Journal articles: 'Fe-Co square complexes'

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Balouch, Aamna, Najma Memon, Muhammad I. Bhanger, and Muhammad Y. Khuhawar. "Utilization of Picolinaldehyde-4-phenyl-3-thiosemicarbazone in Sodium Dodecylsulfate Micelles for the Spectrophotometric Determination of Iron, Vanadium, and Cobalt Following Partial Least-Squares Regression Analysis." Journal of AOAC INTERNATIONAL 92, no. 1 (January 1, 2009): 248–56. http://dx.doi.org/10.1093/jaoac/92.1.248.

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Abstract Partial least-squares regression was applied for the simultaneous determination of iron, vanadium, and cobalt after complexation with picolinaldehyde-4-phenyl-3-thiosemicarbazone (PAPT) in the presence of anionic sodium dodecylsulfate (SDS) micelles. These 3 complexed metal ions exhibited overlapping spectra in the 390510 nm region with a maximum absorbance at 415 nm at pH 3.0 and enhanced absorbance in the presence of SDS. The data for the simultaneous determination of these metal ions were analyzed using a simple partial least-squares (SIMPLS) algorithm. Formation constants (log Kf) were found to be 4.65, 3.29, and 4.85 for PAPT complexes of Fe, V, and Co, respectively, and the detection limits for Fe, V, and Co were 0.013, 0.002, and 0.010 g/mL, respectively. Common anions and cations did not interfere with the proposed method. The method was validated by calculating root mean square error of cross-validation, root mean square error of calibration, and root mean square error of prediction and was applied to determine these 3 metal ions in real crude oil samples.

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Pascualini, M. E., S. A. Stoian, A. Ozarowski, N. V. Di Russo, A. E. Thuijs, K. A. Abboud, G. Christou, and A. S. Veige. "Synthesis and characterization of a family of M2+ complexes supported by a trianionic ONO3− pincer-type ligand: towards the stabilization of high-spin square-planar complexes." Dalton Transactions 44, no. 46 (2015): 20207–15. http://dx.doi.org/10.1039/c5dt03960f.

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Journal, Baghdad Science. "Synthesis of Some Mixed ligands Complexes of (2-hydroxy benzaldine)-4-amino Antipyrine and 1,10-phenanthroline and Studying their antibacterial activity." Baghdad Science Journal 14, no. 1 (March 5, 2017): 39–47. http://dx.doi.org/10.21123/bsj.14.1.39-47.

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Complexes from the ligand (2-hydroxy benzaldine)-4-aminoantipyrine with some transition metal ions V(l?),Cr(lll),Fe(lll) and Co(ll) were prepared in the presence of the co-ligand 1,10-phenanthroline in alcoholic medium. These compounds were characterized by the available techniques: FT-IR ,UV-Visible ,magnetic susceptibility, Flame atomic absorption technique as well as elemental analysis and conductivity mesurments .From these spectral studies, a square pyramidal structure proposed for V(IV) complex and an octahedral geometry for Cr(III),Fe(III) and Co(II) complexes. The biological activity of the ligands and their complexes were evaluated by a gar plate diffusion technique against three human pathogenic bacterial strains: Pseudomonas aerogenuosa, E.schriachia coli. and Staphlococcus arureus. Some of the complexes were found to have a good antibacterial activity a gainst these pathogens.

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Neelamma, M., P. Venkateswar Rao, and G. H. Anuradha. "Synthesis and Structural Studies on Transition Metal Complexes Derived from 4-Hydroxy-4-methyl–2-pentanone-1H-benzimidazol-2-yl-hydrazone." E-Journal of Chemistry 8, no. 1 (2011): 29–36. http://dx.doi.org/10.1155/2011/323404.

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Transition metal complexes of Cr(III), Fe(III), Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) with a tridentate ligand, 4-hydroxy-4-methyl-2-pentanone-1H-benzimidazole-2yl-hydrazone (H-HPBH) derived from the condensation of 2-hydrazinobenzimidazole and diacetone alcohol was synthesized. Characterization has been done on the basis of analytical, conductance, thermal and magnetic data, infrared,1H NMR, electronic, mass and ESR spectral data. From analytical and thermal data, the stoichiometry of the complexes has been found to be 1:1 (metal: ligand). Divalent complexes have the general formula [M(HPBH)Cl(H2O)2] in octahedral geometry, [M(HPBH)Cl] in tetrahedral and square planar stereochemistries and trivalent complexes [M(HPBH)Cl2(H2O)] in octahedral disposition. Infrared spectral data suggest that the ligand HPBH behaves as a monobasic tridentate ligand with N: N: O donor sequence towards the metal ions. On the basis of the above physicochemical data, octahedral, tetrahedral and square planar geometries were assigned for the complexes. The ligand and metal complexes were screened for their physiological activities againstE. coliandS. aureus. The order of physiological activity has been found to be Cu(II) > Ni(II) > Zn(II) > Co(II) > Cr(III) > Mn(II) > Fe (III) > ligand againstE.coliand Ni(II) > Cu(II) > Zn(II) > Mn(II) > Cr(III) > Fe(III) > Co(II) > ligand againstS. aureus.

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Munde, Achut, Amarnath Jagdale, Sarika Jadhav, and Trimbak Chondhekar. "Synthesis, characterization and thermal study of some transition metal complexes of an asymmetrical tetradentate Schiff base ligand." Journal of the Serbian Chemical Society 75, no. 3 (2010): 349–59. http://dx.doi.org/10.2298/jsc090408009m.

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Complexes of Cu(II), Ni(II), Co(II), Mn(II) and Fe(II) with an asymmetric tetradentate Schiff base ligand derived from dehydroacetic acid, 4-methyl- o-phenylenediamine and salicylic aldehyde were synthesized and characterized by elemental analysis, conductometry, magnetic susceptibility, UV-Vis, IR, 1H-NMR spectroscopy, X-ray diffraction analysis of powdered samples and thermal analysis, and screened for antimicrobial activity. The IR spectral data suggested that the ligand behaves as a dibasic tetadentate ligand towards the central metal ion with an ONNO donor atoms sequence. From the microanalytical data, the stoichiometry of the complexes 1:1 (metal:ligand) was found. The physico-chemical data suggested square planar geometry for the Cu(II) and Ni(II) complexes and octahedral geometry for the Co(II), Mn(II) and Fe(II) complexes. The thermal behaviour (TGA/DTA) of the complexes was studied and kinetic parameters were determined by Horowitz-Metzger and Coats-Redfern methods. The powder X-ray diffraction data suggested a monoclinic crystal system for the Co(II), Mn(II) and Fe(II) complexes. The ligand and their metal complexes were screened for antibacterial activity against Staphylococcus aureus and Escherichia coli and fungicidal activity against Aspergillus niger and Trichoderma viride.

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Holland, Amanda M., Allen G. Oliver, and Vlad M. Iluc. "Iron pyrrole-based PNP pincer ligand complexes as catalyst precursors." Acta Crystallographica Section C Structural Chemistry 73, no. 7 (June 28, 2017): 569–74. http://dx.doi.org/10.1107/s2053229617009287.

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The structure of a pincer ligand consists of a backbone and two `arms' which typically contain a P or N atom. They are tridentate ligands that coordinate to a metal center in a meridional configuration. A series of three iron complexes containing the pyrrole-based PNP pincer ligand 2,5-bis[(diisopropylphosphanyl)methyl]pyrrolide (PNpyrP) has been synthesized. These complexes are possible precursors to new iron catalysts. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}carbonylchlorido(trimethylphosphane-κP)iron(II), [Fe(C18H34NP2)Cl(C3H9P)(CO)] or [Fe(PNpyrP)Cl(PMe3)(CO)], (I), has a slightly distorted octahedral geometry, with the Cl and CO ligands occupying the apical positions. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}chlorido(pyridine-κN)iron(II), [Fe(C18H34NP2)Cl(C5H5N)] or [Fe(PNpyrP)Cl(py)] (py is pyridine), (II), is a five-coordinate square-pyramidal complex, with the pyridine ligand in the apical position. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}dicarbonylchloridoiron(II), [Fe(C18H34NP2)Cl(CO)2] or [Fe(PNpyrP)Cl(CO)2], (III), is structurally similar to (I), but with the PMe3 ligand replaced by a second carbonyl ligand from the reaction of (II) with CO. The two carbonyl ligands are in a cis configuration, and there is positional disorder of the chloride and trans carbonyl ligands.

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Journal, Baghdad Science. "Synthesis, Structural Studies of Some New Transition Metals Complexes of Semicarbazide hydro chloride Schiff Base Derivatives." Baghdad Science Journal 10, no. 3 (September 1, 2013): 583–96. http://dx.doi.org/10.21123/bsj.10.3.583-596.

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A new series of transition metal complexes of Cu(II), Ni(II), Co(II) and Fe(III) have been synthesized from the Schiff base (L1) and (L2) derived from Semicarbazide hydro chloride and 4-chlorobenzaldehyde or 4-bromobenzaldehyde. The structural features have been arrived from their elemental analyses, magnetic susceptibility, molar conductivity, IR, UV-Vis. and 1H NMR spectral studies. The data show that the complexes have composition of [M(L)2](NO3)2 and [Fe(L)2 (NO3)2](NO3) where the M=Co(II),Ni(II) and Cu(II) ;L=L1and L2 type. The magnetic susceptibility and UV-Vis spectral data of the complexes suggest a square planer geometry for Co(II) and Cu(II) but Fe(III) octahedral geometry and Ni(II) tetrahedral geometry around the central metal ion.Hyper Chem-6 program has been used to predict structure geometries of compounds in gas phase .The electrostatic potential of the free ligands were calculated to investigate the reactive sites of the molecules .The heat of formation(?Hf ?) and binding energy(?Eb) at 298K for the free ligands and its metal complexes were calculated by using PM3 method.

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Perez-Gavilan, Ariane, Patrick J. Carroll, and Larry G. Sneddon. "Syntheses and structural characterizations ofcloso and nido 10-vertex metallatricarbanonaboranes." Collection of Czechoslovak Chemical Communications 75, no. 9 (2010): 905–17. http://dx.doi.org/10.1135/cccc2010055.

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Deboronation of the 11-vertex metallatricarbadecaboranes 1-(η5-C5H5)-2-Ph-closo-1,2,3,4-M-C3B7H9 [M = Ru, Fe] and 1,1,1-(CO)3-2-Ph-closo-1,2,3,4-M-C3B7H9 [M = Re] with tetrabutylammonium fluoride (TBAF) produced the first examples of the 10-vertex families of closo and nido metallatricarbanonaborane complexes, 2-(η5-C5H5)-10-Ph-closo-2,1,6,10-M-C3B6H8 [M = Ru (1), Fe (2)] and 5,5,5-(CO)3-10-Ph-nido-5,6,9,10-Re-C3B6H9– (3). Crystallographic characterizations of 1 and 3 confirmed geometries, based on a bicapped square antiprism for 1 and a bicapped square antiprism with one missing vertex for 3, that are consistent with their respective 22 (closo) and 24 (nido) skeletal-electron counts.

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Yadav, M., and Debasis Behera. "Synthesis, Characterization, and Biological Activity of Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) Complexes of N-Thiophenoyl-N′-Phenylthiocarbohydrazide." Journal of Chemistry 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/721397.

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Mn(II), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complex of N-thiophenoyl -N′-phenylthiocarbohydrazide (H2TPTH) have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, infrared, NMR, electronic, and ESR spectral studies. The complexes were found to have compositions [Mn(H TPTH)2], [Co(TPTH) (H2O)2], [Ni(TPTH) (H2O)2], [Cu(TPTH)], [Zn(H TPTH)], [Cd(H TPTH)2], and [Fe(H TPTH)2(EtOH)]. The magnetic and electronic spectral studies suggest square planar geometry for [Cu(TPTH)], tetrahedral geometry for [Zn(TPTH)] and [Cd(H TPTH)2], and octahedral geometry for rest of the complexes. The infrared spectral studies of the 1 : 1 deprotonated complexes suggest bonding through enolic oxygen, thiolato sulfur, and both the hydrazinic nitrogens. Thus, H2TPTH acts as a binegative tetradentate ligand. H2TPTH and its metal complexes have been screened against several bacteria and fungi.

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Santoro, Amedeo, Carlo Sambiagio, Patrick C. McGowan, and Malcolm A. Halcrow. "Synthesis and coordination chemistry of 1,1,1-tris-(pyrid-2-yl)ethane." Dalton Transactions 44, no. 3 (2015): 1060–69. http://dx.doi.org/10.1039/c4dt02824d.

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The complexes [ML₂]ⁿ⁺(Mⁿ⁺= Fe²⁺, Co²⁺, Co³⁺, Cu²⁺and Ag⁺), [PdCl₂L] and [CuI(L)] are described. [AgL₂]⁺is an unusual square planar silver(i) centre (left). Exposure of [CuI(L)] to air affords mono- or dinuclear copper(ii)/carbonato products. Two of the copper complexes form crystalline hydrates with complicated hydrogen bond networks (right).

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Chan, Yu-Te, and Ming-Kang Tsai. "CO2 reduction catalysis by tunable square-planar transition-metal complexes: a theoretical investigation using nitrogen-substituted carbon nanotube models." Physical Chemistry Chemical Physics 19, no. 43 (2017): 29068–76. http://dx.doi.org/10.1039/c7cp06024f.

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The CO₂ reduction capabilities of transition-metal-chelated nitrogen-substituted carbon nanotube models (TM-4N2v-CNT, TM = Fe, Ru, Os, Co, Rh, Ir, Ni, Pt or Cu) are characterized by density functional theory.

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Deshpande, Dr Vilas G. "Study of Metal Complexes with Schiff Base Derived from 2-Amino-4, 6-dimethylbenzothiazole and Pyrrole-2- aldehyde." International Journal for Research in Applied Science and Engineering Technology 9, no. VIII (August 15, 2021): 931–36. http://dx.doi.org/10.22214/ijraset.2021.37518.

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As it is proved that the transition metal complexes have drug activities, hence we have synthesized heterocyclic Schiff bases. Six complexes of Co(II), Ni(II), Fe(III), Mn(II), Cr(II) and Cu(II) Schiff bases have been prepared. All ligands and its metal complexes the structures of the complexes have been proposed by analytical data, conductivity measurement, magnetic moment, IR, 1H NMR spectra and thermal studies. Analytical data confirmed 1:2 (metal:ligand) stoichiometry and the spectral data suggest that all Fe(III), Mn(II), Cr(II), Ni(II) and Co(II) complexes have octahedral geometry where as the Cu(II) metal complex shows the square planar geometry. The molar conductance values of metal complexes suggest their non electrolytic nature. The IR spectral data reveals that the ligand behaves as bidentate with O,N donor atoms sequence towards central metal ion. Antibacterial and antifungal activities of ligands and its metal complexes were performed in vitro against E.coli, S. typhi, S. aureus, B. subtilis and against various fungi like P.chrysogenum, A. niger, F. moniliformae, and A.Flavus. The complexes show more activity compare to the ligand.

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Liu, Yuan-Zhong, Jing Wang, Yue Zhao, Lei Chen, Xue-Tai Chen, and Zi-Ling Xue. "Four-coordinate Co(ii) and Fe(ii) complexes with bis(N-heterocyclic carbene)borate and their magnetic properties." Dalton Transactions 44, no. 3 (2015): 908–11. http://dx.doi.org/10.1039/c4dt02537g.

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Both square planar and tetrahedral isomers of the four-coordinate Co(ii) complex with a bis(N-heterocyclic carbene)borate ligand were isolated while only a tetrahedral configuration was found for the Fe(ii) analogue.

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Melnik, Milan, and Peter Mikus. "Stereochemistry of heterobinuclear Pt-M complexes." Reviews in Inorganic Chemistry 37, no. 3-4 (November 27, 2017): 131–46. http://dx.doi.org/10.1515/revic-2017-0009.

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AbstractIn this review, the structural parameters of almost 30 isomers of heterobinuclear Pt-M (M=Sn, Tl, Cu, Ag, Ti, W, Cr, Fe, Co, Ni, Mn, Pd, or Rh) complexes are summarized and analyzed. There are three types of isomers: distortion (by far the prevailing type), polymerization, and mixed isomers. On the basis of Pt-M distance, there are two groups of complexes: one in which the Pt-M bond distances are <3.0 Å (M=Sn, Tl, W, Cr, Mn, Ni, or Pd) and the other one in which the Pt-M separations are >3.0 Å (M=Cu, Ag, Ti, W, Fe, Co, or Rh). Platinum atoms exist in two oxidation states: +2 and +4. The former by far prevails with a square-planar arrangement with varying degrees of distortion. The Pt(IV) atoms are six-coordinated. The inner coordination spheres about M atoms range from two-coordinated (AgNCl) to sandwiched (FeC10). There is wide variety of donor atoms (ligands) (H, OL, NL, CL, BL, Cl, SL, PL, Br, or I) that build up the respective inner coordination spheres about central metal atoms.

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El-Boraey, Hanaa A., and Ohyla A. EL-Gammal. "Novel (N4) Macrocyclic Metal Complexes: Synthesis, Characterization, Spectral Studies and Anticancer Activity." Open Chemistry Journal 5, no. 1 (June 29, 2018): 51–63. http://dx.doi.org/10.2174/1874842201805010051.

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Introduction:A new series of mononuclear Fe(II), Co(II), Ni(II), Cu(II) and Pd(II) complexes correspond to tetradentate macrocyclic nitrogen ligandi.e.naphthyl-3,4:10,11-dibenzo,7-methylene,8-methyl,6-phenyl-1,5,9,13-tetraazacyclohexadecane-5,8-diene-2,12-dione metal(II) complexes, have been synthesized by the template condensation reaction.Methods:The complexes have been characterized by elemental analysis, spectral (IR, UV–Vis, and ESR, molar conductivity, and magnetic as well as thermal analysis measurements.Results:On the basis of above studies, an octahedral geometry has been proposed for all complexes except Cu(II) nitrate complex that adopt square pyramidal geometry, and square planar geometry for Pd(II) chloride complex, respectively.Conclusion:The thermal behavior and the kinetic parameters of degradation were determined using Coats-Redfern and Horowitz-Metzger methods. Moreover, thein vitroantitumor activity of the some synthesized complexes against human breast and human hepatocarcinoma cell lines (MCF-7) and (HePG2), respectively has been studied.

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Hanan, Garry S., Dirk Volkmer, and Jean-Marie Lehn. "Coordination arrays Synthesis and characterization of tetranuclear complexes of grid-type." Canadian Journal of Chemistry 82, no. 10 (October 1, 2004): 1428–34. http://dx.doi.org/10.1139/v04-092.

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A series of tetranuclear metal complexes of grid-type consisting of four bis-tridentate ligands and four divalent transition metal ions were synthesized and characterized. The 1H NMR spectra of diamagnetic complexes containing Zn(II), Cd(II), Fe(II), and Ru(II) was correlated to the radius of the metal ion. The UVvis and electrochemical results indicated that the bridging ligand π* orbital and the dπ metal orbital are stabilized by complexation of more than one metal ion. Furthermore, the Co(II) and Fe(II) grids exhibit metalmetal interaction mediated by the bis-tridentate ligands as indicated by electrochemical and spectroscopic methods. These results provide guidelines for the design of larger grids bearing several metal centres in a square arrangement, which also represent potential components of molecular electronic devices.Key words: complexes with nitrogen ligands, octahedral metal ions, self-assembly, supramolecular chemistry.

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Malarvizhi, M., G. Subramanian, and PR Athappan. "Template Synthesis, Spectral and Redox Behavior of Metal Complexes of Macrocyclic Tetraaza Schiff Base and their Interaction with Herring Sperm DNA." Materials Science Forum 699 (September 2011): 205–29. http://dx.doi.org/10.4028/www.scientific.net/msf.699.205.

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This paper documents the detailed investigation of the relationship between molecular structure and biological activity of few tetraaza macrocyclic metal (II) complexes equipped by the template condensation of o-bromoaniline, ethylenediamine and salbenz in 2:1:1 ratio with metal (II) salts (1mM). All these complexes are found to be stable in air and soluble in CN3CN or DMSO, and are characterized through spectral (UV-Vis, IR, EPR) and electrochemical methods. A square planar geometry is proposed for Cu(II), Ni(II) and Co(II) complexes, while an octahedral geometry is suggested for Mn(II) and Fe(II). The IR spectra indicate that the NH groups of the amine exist as such even after complexation without deprotonation, and all the complexes show a strong band in 1580-1590 cm-1region corresponding to ν(C=N), due to coordinated azomethine group to the metal. The solution electronic spectra of these complexes show intense LMCT bands around 400 nm. Intense electronic absorption spectra as well as the four line pattern in EPR spectra with broad g⊥suggests that the copper(II) complexes have distorted square planar geometry. On titration with herring sperm DNA, CuN4,CoN4,NiN4and MnN4complexes exhibit an abrupt amend in their electronic spectrum and cyclic voltammogram. The intense intraligand π-π* transition in the region 350–420 nm is found to show hypochromicity on titration with DNA in all these complexes, due to their electrostatic interaction with DNA. All these complexes show one well–defined quasi-reversible redox couple with values ranging from ∆Ep 137 to 337 mV. Their spectral and electrochemical outcome designate that the square planar complexes Cu(II), Co(II) and Ni(II) interact much better than the axially coordinated octahedral complexes Mn(II) and Fe(II). The decrease found in the negative absorption peak, characteristic peak due to helicity of DNA, in circular dichroism studies reflects the perversion in the helical nature of B-DNA upon the addition of complex. The binding of plasmid DNA by these complexes has also been investigated by agarose gel electrophoresis, remarkably Ni(II) complex was found to cleave the DNA double helix.

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Hassan, Zainab M., Rawaa A. Alattar, Suhad Kareem Abass, Hayder Hamied Mihsen, Zainab Fadhil Abbas, and Khalid A. Hussain. "Synthesis, Characterization and Biological Activity of Mixed Ligand (Imine of Benzidine and 1,10-Phenanthroline) Complexes with Fe(II), Co(II), Ni(II) and Cu(II) Ions." Chemistry & Chemical Technology 16, no. 1 (February 20, 2022): 15–24. http://dx.doi.org/10.23939/chcht16.01.015.

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In this paper, binuclear metal complexes of the metal ions Fe(II), Co(II), Ni(II) and Cu(II) were synthesized by the reaction of the primary ligand (imine of benzidine) (H2L) and the secondary ligand (1,10-phenanthroline) (L`) with these metal ions in a molar ratio of 1:2:2, respectively. The complexes were characterized using CHN elemental analysis, FT-IR, UV-Vis, magnetic susceptibility, molar conductivity, 1H NMR, and TGA-DTA thermogravimetric analysis. According to the results obtained from the elemental analysis and spectral measurements where complexes of Fe(II), Co(II) and Ni(II) have octahedral geometry, while the complex with Cu(II) has a square planar geometry. All the prepared complexes are wholly stable and can keep for months without any significant change. The antibacterial activities of the prepared compounds were evaluated with regard to two bacteria species, gram-negative Proteus and Kelbsiella, by using diffusion agar plates. The inhibition zone diameter around the holes indicated the sensitivity of the bacteria to these compounds, where the Klebsiella bacteria were revealed to be more highly sensitive to these compounds than Proteus bacteria. All synthesized complexes showed more significant effects against Kelbsiella and Protea than the antibiotic (Amikacin).

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Journal, Baghdad Science. "Synthesis, characterization and antimicrobial Studies of complexes of some metal ions with 5(2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole." Baghdad Science Journal 7, no. 1 (March 7, 2010): 585–92. http://dx.doi.org/10.21123/bsj.7.1.585-592.

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A new series of Fe (III) , Co (II) , Ni (II) and Cu (II) complexes of the Schiff base, 5 (2-hydroxy benzylidine) -2-thio ether -1, 3, 4-thiadiazole were prepared and characterized .The imine behaves as a bidentate. The nature of bonding and the stereochemistry of the complexes were deduced from metal analyses, infrared, electronic spectra,magnetic susceptibility and conductivity measurements, an octahedral geometry was suggested for all complexes except the copper complex has a square planar geometry .preliminary in vitro tests for antimicrobial activity show that all the prepared compounds except iron complex display good activity to gram positive Staphelococcus aures and gram negative Escherchia coli.

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De, Siddhartha, Juan-Ramón Jiménez, Yanling Li, Lise-Marie Chamoreau, Alexandrine Flambard, Yves Journaux, Azzedine Bousseksou, and Rodrigue Lescouëzec. "One synthesis: two redox states. Temperature-oriented crystallization of a charge transfer {Fe2Co2} square complex in a {FeIILSCoIIILS}2 diamagnetic or {FeIIILSCoIIHS}2 paramagnetic state." RSC Advances 6, no. 21 (2016): 17456–59. http://dx.doi.org/10.1039/c6ra00191b.

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The reaction of [Fe^III(Tp)(CN)₃]⁻ with [Co^II(vbik)₂(S)₂]²⁺ leads selectively to the crystallization of cyanide-bridged diamagnetic {FeIILSCoIIILS}₂ charge-transfer complexes at 5 °C or paramagnetic {FeIIILSCoIIHS}₂ ones at 35 °C.

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Dhanmane, Sushilkumar, Melwin D'souza, Raj Badekar, and Arun Kadu. "Synthesis, Spectral and Theoretical Characterization and Antimicrobial and Cytotoxic Studies of Some Transition Metal Complexes of 4-[(2E)-2-Benzylidenehydrazinyl]-7H-pyrrolo[2,3-d]pyrimidine." Asian Journal of Chemistry 35, no. 8 (2023): 1963–68. http://dx.doi.org/10.14233/ajchem.2023.28007.

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Present work describes the synthesis and characterization of complexes of 4-[(2E)-2-benzylidenehydrazinyl]-7H-pyrrolo[2,3-d]pyrimidine with Fe(II), Mn(II), Co(II), Ni(II), Pd(II), Zn(II), Cu(II), Cd(II) and Hg(II). The results of the elemental and spectroscopic analyses suggest a 1:2 metal-ligand ratio, [ML2]. The electronic spectra and magnetic moments of the metal(II) complexes suggest that Fe(II), Mn(II), Co(II) and Ni(II) complexes are in an octahedral geometry, while Pd(II) in a square planar ligand geometry. In contrast, the Cu(II), Zn(II), Cd(II) and Hg(II) are in tetrahedral geometry. The conductance measurements in nitrobenzene suggest the non-electrolytic nature of all the metal-coordination compounds. The tested biological species viz. Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Bacillus cereus, Proteus mirabilis, Klebsiella oxytoca, Aspergillus niger, A. flavus and Rhizopus stolonifer exhibited the moderate to strong antimicrobial activity. At 10 mg/mL concentration in nitrobenzene, cobalt(II) complex is observed to be a more promising antimicrobial than any other metal(II) complexes synthesized. The antioxidant potential of the synthesized metal(II) compounds was also evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and shows the high DPPH radical scavenging activity. The nickel complex had the highest DPPH radical scavenging activity compared to the other metal(II) complexes.

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Emama, Sanaa M., Saeyda A. AbouEl-Enein, Sanaa A. Othman, and Eman M. El-Mahdey. "Novel metal chelates with thiourea and nicotinic acid: Synthesis, structural characterization, and biological properties." Current Chemistry Letters 12, no. 2 (2023): 317–34. http://dx.doi.org/10.5267/j.ccl.2022.12.007.

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The interaction of nicotinic acid and thiourea with the chloride salts of Ca(II), Mg(II), Co(II), Ni(II), Cu(II), and Fe(III) ions led to the synthesis of a unique series of metal chelates. All formed metal complexes were clarified using a variety of analytical and spectral techniques, besides magnetic moment and thermal tests. The electronic and magnetic measurements indicated that the paramagnetic chelates (3) and (4), as well as the diamagnetic complexes (1) and (2), were responsible for the tetrahedral geometrical structure. The outcomes also led to the production of square-planar, and high-spin octahedral structures for chelates (5) and (6). Thermodynamic studies using activation energy values revealed that complex (1) is more thermally stable than complex (2) and complex (3) is more stable than complex (4). Fe(III) complex exhibits higher antibacterial and antifungal activities than other metal complexes. Chelate (6) exhibits the highest rate of germination in wheat.

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Mohammed, Enas Hazim, Sahbaa Ali Ahmed, and Sariya Waleed Zedan. "Synthesis, characterization and spectral studies of mononuclear and binuclear Fe(II), Co (II), Ni (II), Zn(II) complexes with 2,4-dinitrophenylhydrazine dithiocarbamate." Journal of Physics: Conference Series 2063, no. 1 (November 1, 2021): 012030. http://dx.doi.org/10.1088/1742-6596/2063/1/012030.

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Abstract New complexes of dithiocarbamate of the general formula [M(2,4-dinitrphenhydra - dtc)2], [MM’(2,4-dinithrphenhydra-dtc)4] where: M=Fe (II), Co(II), Ni(II), M’=Zn(II), 2,4- dinitrphenhydra-dtc=2,4- di nitro phenyl hydrazine dithiocarbamate and [M(l,10-phen)3][M’(2,4 – dinitrphenhydra-dtc)4], [M(1,10- phen)3][M’2(2,4-dinitrphenhydra - dtc)6] Where: M=Co(II), Ni(II), M’=Zn(II), (1,10-phen)= 1,10-phenanthroline monohydrate. Have been prepared and characterized by atomic absorption spectroscopy infrared, conductance measurements, electronic absorption spectra, nuclear magnetic resonance and magnetic susceptibility measurements. Magnetic moments and electronic spectra indicate that the complexes of the type [M(2,-dinitrphenhydra-dtc)2], [MM’(2,4-dinitrphenhydra - dtc)4] are of square planner geometry while the complexes of the type [M(1,10-phen)3][M’(2,4-dinitrphenhydra-dtc)4] and [M(1,10 phen)3][M’2(2,4-dinitrphenhydra-dtc)6] have octahedral geometry.

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24

Matemadombo, Fungisai, M. David Maree, Kenneth I. Ozoemena, Philippe Westbroek, and Tebello Nyokong. "Synthesis, electrochemical and spectroelectrochemical studies of octaphenylthio-substituted phthalocyanines." Journal of Porphyrins and Phthalocyanines 09, no. 07 (July 2005): 484–90. http://dx.doi.org/10.1142/s1088424605000605.

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Cobalt (4) and iron (5) phenylthio-substituted phthalocyanines ( MPc ( SR )8) have been synthesized and characterized. Cyclic square wave voltammetry in dimethylformamide containing tetrabutylammonium perchlorate revealed five and six redox processes, respectively, for complexes 4 and 5. The complexes are easier to reduce compared to the corresponding unsubstituted MPc and to butylthio substituted derivatives. The first oxidation and reduction occurs on the metal for both complexes. Spectroelectrochemistry (in dimethylformamide containing tetrabutylammonium perchlorate) was employed to assign the cyclic voltammetry peaks, and gave spectra characteristic of Fe I Pc for reduction of 5 and Co I Pc for the reduction of 4. The spectrum of the former is particularly of importance since such species have not received much attention in the literature.

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25

Spînu, C., M. Pleniceanu, and C. Tigae. "Biologically active new Fe(II), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes of N-(2-thienylmethylene)methanamine." Journal of the Serbian Chemical Society 73, no. 4 (2008): 415–21. http://dx.doi.org/10.2298/jsc0804415s.

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Iron(II), cobalt(II), nickel (II), copper (II), zinc(II) and cadmium(II) complexes of the type ML2Cl2, where M is a metal and L is the Schiff base N- -(2-thienylmethylene)methanamine (TNAM) formed by the condensation of 2- -thiophenecarboxaldehyde and methylamine, were prepared and characterized by elemental analysis as well as magnetic and spectroscopic measurements. The elemental analyses suggest the stoichiometry to be 1:2 (metal:ligand). Magnetic susceptibility data coupled with electronic, ESR and M?ssbauer spectra suggest a distorted octahedral structure for the Fe(II), Co(II) and Ni(II) complexes, a square-planar geometry for the Cu(II) compound and a tetrahedral geometry for the Zn(II) and Cd(II) complexes. The infrared and NMR spectra of the complexes agree with co-ordination to the central metal atom through nitrogen and sulphur atoms. Conductance measurements suggest the non-electrolytic nature of the complexes, except for the Cu(II), Zn(II) and Cd(II) complexes, which are 1:2 electrolytes. The Schiff base and its metal chelates were screened for their biological activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the metal chelates were found to possess better antibacterial activity than that of the uncomplexed Schiff base.

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Journal, Baghdad Science. "Some new transition metal complexes of bis (2-methyl furfuraldene)-4,4`-methylene bis (cyclohexylamine) ligand." Baghdad Science Journal 10, no. 3 (September 1, 2013): 569–82. http://dx.doi.org/10.21123/bsj.10.3.569-582.

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New Fe(II),Co(II),Ni(II),Cu(II) and Zn(II) Schiff base complexes which have the molar ratio 2:1 metal to ligand of the general formula [M2( L) X4] (where L=bis(2-methyl furfuraldene)-4-4`-methylene bis(cyclo-hexylamine) ) were prepared by the reaction of the metal salts with the ligand of Schiff base derived from the condensation of 2:1 molar ratio of 2-acetyl furan and 4-4`-methylene bis (cyclohexylamine). The complexes were characterized by elemental analysis using atomic absorption spectrophotometer ,molar conductance measurements, infrared, electronic spectra,and magnetic susceptibility measurement. These studies revealed binuclear omplexes. The metal(II) ion in these complexes have four coordination sites giving the most expected tetrahedral structure and square planar for Cu(II)ion.

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27

Yang, Xuemei, Allen Lunsford, and Marcetta Y. Darensbourg. "Connecting Main-Group Metals (Al, Ga, In) and Tungsten(0) Carbonyls via the N2S2 Metallo-Ligand Strategy." Inorganics 7, no. 9 (September 13, 2019): 115. http://dx.doi.org/10.3390/inorganics7090115.

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Tetradentate N2S2 ligands (such as bismercaptoethanediazacycloheptane in this study) have seen extensive use in combination with transition metals. Well-oriented N2S2 binding sites are ideal for d8 transition metals with square planar preferences, especially NiII, but also as a square pyramidal base for those metals with pentacoordinate preferences, such as [V≡O]2+, [Fe(NO)]2+, and [Co(NO)]2+. Further reactivity at the thiolate sulfurs generates diverse bi, tri, and tetra/heterometallic compounds. Few N2S2 ligands have been explored to investigate the possibility of binding to main group metals, especially group III (MIII) metals, and their utility as synthons for main group/transition metal bimetallic complexes. To open up this area of chemistry, we synthesized three new five-coordinate main group XMN2S2 complexes with methyl as the fifth binding ligand for M = Al, and chloride for M = Ga and In. The seven-membered diazacycle, dach, was engaged as a rigid stabilized connector between the terminal thiolate sulfurs. The pentacoordinate XMN2S2 complexes were characterized by 1H-NMR, 13C-NMR, +ESI-Mass spectra, and X-ray diffraction. Their stabilities and reactivities were probed by adding NiII sources and W(CO)5(THF). The former replaces the main group metals in all cases in the N2S2 coordination environment, demonstrating the weak coordinate bonds of MIII–N/S. The reaction of XMN2S2 (XM = ClGaIII or ClInIII) with the labile ligand W(0) complex W(CO)5(THF) resulted in Ga/In–W bimetallic complexes with a thiolate S-bridge. The synthesis of XMN2S2 complexes provide examples of MIII–S coordination, especially Al–S, which is relatively rare. The bimetallic Ga/In–S–W complex formation indicates that the nucleophilic ability of sulfur is retained in MIII–S–R, resulting in the ability of main group MIII–N2S2 complexes to serve as metalloligands.

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28

KAKARLA, Ramana Kumar, Raghavendra Guru Prasad ALURU, Srilalitha VINNAKOTA, and RAO KRISHNA RAO, Ravindranath LAKSHMANA. "SYNTHESIS AND CHARACTERIZATION OF MALONIC ACID DIHYDRAZIDE AND ITS METAL COMPLEXES." Periódico Tchê Química 12, no. 24 (January 20, 2013): 26–33. http://dx.doi.org/10.52571/ptq.v11.n20-21.2013.26_periodico20e21_pgs_26_33.pdf.

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A new series of complexes was synthesized by the reaction between malonyl dihydrazide (MAH) and manganese, copper, nickel, zinc, cadmium, cobalt and ferric salts in methanolic medium. The complexes were characterized by elemental analysis, molar conductance measurements, electronic, IR and 1H NMR spectral studies. Based on the results obtained, the stoichiometry of Fe(III)-MAH and Co(III)-MAH was proposed to be 1:3 and that for Cu(II)-MAH, Cd(II)-MAH, Zn(II)-MAH, Mn(II)-MAH, Ni(II)-MAH was proposed to be 1:2 (M:L). It was suggested that the nitrogen present in the azomethine (>C=N-) group of the enolic form present in the ligand was involved in the formation of complexes. A clear picturisation indicating the bonding sites were depicted for each complex. The metal complexes exhibit different geometries such as tetrahedral, square planar and octahedral arrangements.

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29

Fabiyi, Festus Sunday, and Adesoji Alani Olanrewaju. "Synthesis, Characterization, Thermogravimetric and Antioxidant Studies of New Cu(II), Fe(II), Mn(II), Cu(II), Zn(II), Co(II) and Ni(II) Complexes with Benzoic Acid and 4,4,4-Trifluoro-1-(2-naphthyl)-1,3-butanedione." International Journal of Chemistry 11, no. 1 (April 7, 2019): 60. http://dx.doi.org/10.5539/ijc.v11n1p60.

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Six new Mn(II), Fe(II), Co(II), Ni (II), Cu(II) and Zn(II) complexes with benzoic acid (L) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (L1), of the molecular formulae [MnLL1]·H2O (1), [FeLL1]·H2O (2), [CoLL1] (3), [NiLL1]·H2O (4), [CuLL1] (5) and [ZnLL1] (6), respectively, have been synthesized. The molecular structures of the complexes were determined by spectrophotometric studies using ir, 1H and 13C nmr, es and mass spectrophotometry revealed that the geometries of the complexes 1, 2, 3, and 6 are tetrahedral, while 4 and 5 have square planar geometry. These geometries were supported by their magnetic moments data. The coordination of the ligands to the metal ion are through their oxygen atoms. TGA studies showed that they are thermally stable. Their antioxidant studies revealed that they are good antioxidants.

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30

N. Borase, Jitendra, and Shankarsing S. Rajput. "DESIGN, SYNTHESIS AND BIOLOGICAL PROPERTIES OF TRANSITION METAL COMPLEXES OF SCHIFF BASE LIGAND DERIVED FROM PYRIDINE DERIVATIVES." Journal of Advanced Scientific Research 13, no. 10 (December 3, 2022): 12–24. http://dx.doi.org/10.55218/jasr.2022131003.

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Novel classes of heterocyclic Schiff base ligand were prepared from the condensation of 2-methoxy benzaldehyde and 2-amino 4-methyl pyridine in absolute ethanol in presence of catalytic amount of dilute HCl. The resulted novel class ofheterocyclic ligand was treated with metal salt or acetate results in the formation of Fe (III), Co (III), Ni (II) & Cu (II)complexes. All newly synthesized resulted ligand its metal complexes were characterized by elemental analysis and FTIR,Magnetic susceptibility, Antimicrobial, Antioxidant, ESR spectrum for Copper complex in DMF solvent recorded atroom temperature. The Electronic spectra and magnetic susceptibility measurements indicates that square planer andoctahedral geometry of these complexes also suggest their structure in which (N, O) group acts as bidentate ligand. Thethermal stability, decomposition behavior has been investigated by using thermo gravimetric analysis at heating rate 10°Cper minute with nitrogen atmosphere and their and kinetic parameter was also calculated by using Freeman Carrollmethod. Screening results of antimicrobial, antioxidant activity of transition metal complexes shows good antibacterialand antifungal activity and excellent antioxidant activity.

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31

Pham, Duyen N. K., Mrittika Roy, Ava Kreider-Mueller, James A. Golen, and David R. Manke. "More crystal field theory in action: the metal–4-picoline (pic)–sulfate [M(pic) x ]SO4 complexes (M = Fe, Co, Ni, Cu, Zn, and Cd)." Acta Crystallographica Section C Structural Chemistry 75, no. 5 (April 15, 2019): 568–74. http://dx.doi.org/10.1107/s2053229619004625.

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Seven crystal structures of five first-row (Fe, Co, Ni, Cu, and Zn) and one second-row (Cd) transition metal–4-picoline (pic)–sulfate complexes of the form [M(pic) x ]SO4 are reported. These complexes are catena-poly[[tetrakis(4-methylpyridine-κN)metal(II)]-μ-sulfato-κ2 O:O′], [M(SO4)(C6H7N)4] n , where the metal/M is iron, cobalt, nickel, and cadmium, di-μ-sulfato-κ4 O:O-bis[tris(4-methylpyridine-κN)copper(II)], [Cu2(SO4)2(C6H7N)6], catena-poly[[bis(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)2] n , and catena-poly[[tris(4-methylpyridine-κN)zinc(II)]-μ-sulfato-κ2 O:O′], [Zn(SO4)(C6H7N)3] n . The Fe, Co, Ni, and Cd compounds are isomorphous, displaying polymeric crystal structures with infinite chains of M II ions adopting an octahedral N4O2 coordination environment that involves four picoline ligands and two bridging sulfate anions. The Cu compound features a dimeric crystal structure, with the CuII ions possessing square-pyramidal N3O2 coordination environments that contain three picoline ligands and two bridging sulfate anions. Zinc crystallizes in two forms, one exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a tetrahedral N2O2 coordination containing two picoline ligands and two bridging sulfate anions, and the other exhibiting a polymeric crystal structure with infinite chains of ZnII ions adopting a trigonal bipyramidal N3O2 coordination containing three picoline ligands and two bridging sulfate anions. The structures are compared with the analogous pyridine complexes, and the observed coordination environments are examined in relation to crystal field theory.

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32

Kirschbaum, Kristin, Uta Bönnighausen, Ewald Gesing, Klaus Greiwe, Ulrich Kuhlmann, Henry Strasdeit, Bernt Krebs, and Gerald Henkel. "Eisen- und Cobaltkomplexe mit Schwefelliganden: Darstellung und Kristallstrukturen von [Me4N][FeCl{S2P(OMe)2}2], [Me4N][CoCl{S2P(OMe)2}2], [Et4N][FeCl{S2P(p-C6H4Me)2}2], [Et4N]2[FeCl{ S2PS(OMe) } 2] und [Fe { S2P(OMe)2 }3] / Iron and Cobalt Complexes with Sulfur-Containing Ligands: Preparation and Crystal Structures of [Me4N][FeCl{S2P(OMe)2}2],[Me4N][CoCl{S2P(OMe)2}2], [Et4N][FeCl{S2P(p-C6H4Me)2}2], [Et4N]2[FeCl{S2PS(OMe)}2] and [Fe{S2P(OMe)2}3]." Zeitschrift für Naturforschung B 45, no. 2 (February 1, 1990): 245–57. http://dx.doi.org/10.1515/znb-1990-0219.

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The reaction systems MCl2/K{S2P(OMe)2} (M = Fe(II), Co(II)), FeCl2/Na{S2S2P(p-C6H4Me)2}, and FeCl3/K2{S2PS(OMe)} in methanol afford the mononuclear complexes [FeCl{S2P(OMe)2}2]-, [CoCl{S2P(OMe)2}2]-, [FeCl{S2P(p-C6H4Me)2}2]-, and [FeCl{S2PS(OMe)}2]2-, which were isolated as salts [Me4N][FeCl{S2P(OMe)2}2] (1), [Me4N][CoCl{S2P(OMe)2}2] (2), [Et4N][FeCl{S2P(p-C6H4Me)2}2] (3) and [Et4N]2[FeCl{S2PS(OMe)}2] (4), respectively. Crystals of [Me4N][MCl{S2P(OMe)2}2] are triclinic, space group P 1 (Z = 2): Fe(II), a = 7.165(3), b = 8.628(3), c = 16.526(6)Å, α = 83.98(3), β = 85.32(3), γ = 89.80(3)°; Co(II), a = 7.164(2), b = 8.612(2), c = 16.504(4)Å, α = 84.59(2), β = 84.63(2), γ = 89.41(2)°. The structures of 1 and 2 were refined to R (Rw) = 0.034 (0.043) and 0.028 (0.032), respectively. Compound 3 is monoclinic, space group C2/c, Z = 4 with a = 23.831(5), b = 10.536(3), c = 17.133(4)Å, β = 114.43(3)°. Its structure was refined to R (Rw) = 0.046 (0.052). 4 crystallizes in the orthorhombic space group Pccn with a = 13.310(2), b = 12.982(2), c = 18.968(3) Å, and Z = 4. The refinement converged to R (Rw) = 0.042 (0.039). The anions of the compounds 1—4 contain five-coordinated metal centers which reside in distorted trigonal-bipyramidal (1, 2, and 3) or square pyramidal (4) S4Cl-environments. The neutral complex [Fe{S2P(OMe)2}3] (5) with six-coordinated metal sites was isolated from the reaction system FeCl3/K{S2P(OMe)2} in CH2Cl2. 5 is monoclinic, space group C 2/c (Z = 4) with a = 14.211(2), b = 11.115(2), c = 12.823(2) Å, β = 97.23(1)°. The refinement converged to R (Rw) = 0.022 (0.031). The anions of 1, 2, and 3 represent the first examples of structurally defined mononuclear Fe(II) and Co(II) complexes containing 1,1-dithiolate groups and halide ions simultaneously.

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33

Lin, Wenhua, Liping Zhang, Jiahao Gao, Qiuyue Zhang, Yanping Ma, Hua Liu, and Wen-Hua Sun. "6-Arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)-iminopyridylmetal (Fe and Co) Complexes as Highly Active Precatalysts for Ethylene Polymerization: Influence of Metal and/or Substituents on the Active, Thermostable Performance of Their Complexes and Resultant Polyethylenes." Molecules 25, no. 18 (September 16, 2020): 4244. http://dx.doi.org/10.3390/molecules25184244.

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A series of 6-arylimino-2-(2-(1-phenylethyl)naphthalen-1-yl)iminopyridines and their iron(II) and cobalt(II) complexes (Fe1–Fe5, Co1–Co5) were synthesized and routinely characterized as were Co3 and Co5 complexes, studied by single crystal X-ray crystallography, which individually displayed a distorted square pyramidal or trigonal bipyramid around a cobalt center. Upon treatment with either methyluminoxane (MAO) or modified methyluminoxane (MMAO), all complexes displayed high activities regarding ethylene polymerization even at an elevated temperature, enhancing the thermostability of the active species. In general, iron precatalysts showed higher activities than their cobalt analogs; for example, 10.9 × 106 g(PE) mol−1 (Co) h−1 by Co4 and 17.0 × 106 g(PE) mol−1 (Fe) h−1 by Fe4. Bulkier substituents are favored for increasing the molecular weights of the resultant polyethylenes, such as 25.6 kg mol−1 obtained by Co3 and 297 kg mol−1 obtained by Fe3. A narrow polydispersity of polyethylenes was observed by iron precatalysts activated by MMAO, indicating a single-site active species formed.

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Journal, Baghdad Science. "Synthesis, Characterization, Thermal Analysis and Structural Studies of New Complexes with Tetradentate Ligand." Baghdad Science Journal 12, no. 2 (June 7, 2015): 379–93. http://dx.doi.org/10.21123/bsj.12.2.379-393.

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Some new complexes of 4-(5-(1,5-dimethyl-3-oxo-2-phenyl pyrazolidin-4- ylimino)-3,3-dimethyl cyclohexylideneamino) -1,5- dimethyl-2- phenyl -1H- pyrazol -3(2H) –one (L) with Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Pd(II), Re(V) and Pt(IV) were prepared. The ligand and its metal complexes were characterized by phisco- chemical spectroscopic techniques. The spectral data were suggested that the (L) as a neutral tetradentate ligand is coordinated with the metal ions through two nitrogen and two oxygen atoms. These studies revealed Octahedral geometries for all metal complexes, except square planar for Pd(II) complex. Moreover, the thermodynamic activation parameters, such as ?E*, ?H, ?S, ?G and K are calculated from the TGA curves using Coats –Redfern method. Hyper Chem -8 program has been used to predict structural geometries for compounds in gas phase. The heat of formation (?Hf) and bin ding energy (?Eb) at 298 °K for the free ligand and its metal complexes were calculated by PM3 method. The synthesized ligands and their metal complexes were screened for their biological activity against bacterial species, two Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa).

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35

Beteringhe, Adrian, Ciprian Racuciu, Constantin Balan, Elena Stoican, and Luminita Patron. "Molecular Docking Studies Involving Transitional Metal Complexes (Zn(II), Co(II), Cu(II), Fe(II), Ni(II) with Cholic Acid (AC) as Ligand against Aurora A Kinase." Advanced Materials Research 787 (September 2013): 236–40. http://dx.doi.org/10.4028/www.scientific.net/amr.787.236.

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Colorectal cancer is a malignant tumor, one of the main types of cancer which produces a large number of deaths each year in many countries around the world. The main objective of this work is to employ various bioinformatics tools to perform docking of the transitional metal complexes (Zn (II), Co (II), Cu (II), Fe (II), Ni (II)) with cholic acid (AC) as ligand against Aurora A Kinase (RCSB Protein Data Bank code: 2X6E). Molegro Virtual Docker (MVD) was used for the docking process. The molecular docking score and the values of the statistic parameter Root Mean Square Deviation (RMSD) are presented in Table 1. The results obtained in this study serve to design new complex combinations with potential action against Aurora A Kinase inhibitor.

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Podlahová, Jana, Josef Šilha, and Jaroslav Podlaha. "Structure of the complexes of ethylenediphosphinetetraacetic acid in solution." Collection of Czechoslovak Chemical Communications 50, no. 2 (1985): 445–53. http://dx.doi.org/10.1135/cccc19850445.

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Ethylenediphosphinetetraacetic acid is bonded to metal ions in aqueous solutions in four ways, depending on the type of metal ion: 1) through an ionic bond of the carboxylic groups to form weak complexes with a metal:ligand ratio of 1 : 1 (Ca(II), Mn(II), Zn(II), Pb(II), La(III)); 2) through type 1) bond with contributions from weak interaction with the phosphorus (Cd(II)); 3) through coordination of the ligand as a monodentate P-donor with the free carboxyl groups with formation of 2 : 1 and 1 : 1 complexes (Cu(I), Ag(I)); 4) through formation of square planar or, for Hg(II), tetrahedral complexes with a ratio of 1 : 2 with the ligand as a bidentate PP-donor with the free carboxyl groups (Fe(II), Co(II), Ni(II), Pd(II), Pt(II)). On acidification of the complex solution, the first two protons are bonded to the carboxyl groups. The behaviour during further protonation depends on the type of complex: in complexes of types 1) and 2) phosphorus is protonated and the complex dissociates; in complexes of types 3) and 4) the free carboxyl groups are protonated and the phosphorus-metal bond remains intact. The results are based on correlation of the stability constants, UV-visible, infrared, 1H and 31P NMR spectra and magnetic susceptibilities of the complexes in aqueous solution.

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Körner, Volkmar, Alexander Asam, Gottfried Hüttner, Laszlo Zsolnai, and Michael Büchner. "Fünffach koordinierte Komplexe vom Typ [tripodM-(ortho-(X)(Y)C6H4)]n (X, Y = O, S) bei d5-, d6- und d7-systemen. synthese, struktur, elektrochemie und esr-spektren / Five-coordinate complexes [tripodM-(ortho-(X)(Y)C6H4)]n (X, Y = O, S) with d5-,d6- and d7-Systems. Synthesis, Structure, Electrochemistry and ESR-Spectra." Zeitschrift für Naturforschung B 49, no. 9 (September 1, 1994): 1183–92. http://dx.doi.org/10.1515/znb-1994-0906.

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The d6-Co(III)-species [tripodCo-(ortho-(X)(Y)C6H4)]+ (X, Y = O, S, tripod = CH3C(CH2PPh2)3) 1 are reversibly reduced to the neutral d7-Co(II)-compounds [tripodCo-(ortho-(X)(Y)C6H4)] (X, Y = O, S) 2. Both species show fivefold coordination of cobalt with coordination polyhedra in between the limits of the square pyramid and the trigonal bipyramid respectively. The low-spin d7-species 2 give clearly resolved ESR-spectra revealing the coexistence of two geometric isomers above -80 °C, with only one isomer persistent at temperatures around 100 K.As an analogous d5-system [benzyltripodFe-(ortho-(S)(S)C6H4)]+ 3 (benzyltripod = C6H5CH2C(CH2PPh2)3) has been obtained from [benzyltripodFe(NCCH3)3]2+ and C6H6S2. Alternatively complexes of this type, e.g. [tripodFe-(ortho-(S)(S)C6H4)]+ 4, may be prepared from Fe(H2O)6(BF4)2/tripod/C6H6S2 when the reaction mixture is activated by acidification with HBF4. The geometry of the d5-species 3 and 4 is close to a trigonal bipyramid

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Jędrzejowska, Katarzyna, Jedrzej Kobylarczyk, Dorota Glosz, Emilia Kuzniak-Glanowska, Dominika Tabor, Monika Srebro-Hooper, Jakub J. Zakrzewski, Katarzyna Dziedzic-Kocurek, Tadeusz M. Muzioł, and Robert Podgajny. "Supramolecular cis-“Bis(Chelation)” of [M(CN)6]3− (M = CrIII, FeIII, CoIII) by Phloroglucinol (H3PG)." Molecules 27, no. 13 (June 26, 2022): 4111. http://dx.doi.org/10.3390/molecules27134111.

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Studies on molecular co-crystal type materials are important in the design and preparation of easy-to-absorb drugs, non-centrosymmetric, and chiral crystals for optical performance, liquid crystals, or plastic phases. From a fundamental point of view, such studies also provide useful information on various supramolecular synthons and molecular ordering, including metric parameters, molecular matching, energetical hierarchy, and combinatorial potential, appealing to the rational design of functional materials through structure–properties–application schemes. Co-crystal salts involving anionic d-metallate coordination complexes are moderately explored (compared to the generality of co-crystals), and in this context, we present a new series of isomorphous co-crystalline salts (PPh4)3[M(CN)6](H3PG)2·2MeCN (M = Cr, 1; Fe, 2; Co 3; H3PG = phloroglucinol, 1,3,5-trihydroxobenzene). In this study, 1–3 were characterized experimentally using SC XRD, Hirshfeld analysis, ESI-MS spectrometry, vibrational IR and Raman, 57Fe Mössbauer, electronic absorption UV-Vis-NIR, and photoluminescence spectroscopies, and theoretically with density functional theory calculations. The two-dimensional square grid-like hydrogen-bond {[M(CN)6]3−;(H3PG)2}∞ network features original {[M(CN)6]3−;(H3PG)4} supramolecular cis-bis(chelate) motifs involving: (i) two double cyclic hydrogen bond synthons M(-CN⋅⋅⋅HO-)2Ar, {[M(CN)6]3−;H2PGH}, between cis-oriented cyanido ligands of [M(CN)6]3− and resorcinol-like face of H3PG, and (ii) two single hydrogen bonds M-CN⋅⋅⋅HO-Ar, {[M(CN)6]3−;HPGH2}, involving the remaining two cyanide ligands. The occurrence of the above tectonic motif is discussed with regard to the relevant data existing in the CCDC database, including the multisite H-bond binding of [M(CN)6]3− by organic species, mononuclear coordination complexes, and polynuclear complexes. The physicochemical and computational characterization discloses notable spectral modifications under the regime of an extended hydrogen bond network.

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39

Harrison, Daniel J., Alan J. Lough, and Ulrich Fekl. "A new structural model for NiFe hydrogenases: an unsaturated analogue of a classic hydrogenase model leads to more enzyme-like Ni—Fe distance and interplanar fold." Acta Crystallographica Section E Crystallographic Communications 74, no. 9 (August 14, 2018): 1222–26. http://dx.doi.org/10.1107/s2056989018010939.

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The complex cation in the title compound, (carbonyl-1κC)(1η5-pentamethylcyclopentadienyl)(μ-2,3,9,10-tetramethyl-1,4,8,11-tetrathiaundeca-2,9-diene-1,11-diido-1κ2 S,S′′′:2κ4 S,S′,S′′,S′′′)ironnickel(Fe—Ni) hexafluorophosphate, [FeNi(C10H15)(C11H18S4)(CO)]PF6 or [Ni(L′)FeCp*(CO)]PF6, is composed of the nickel complex fragment [Ni(L′)] coordinated as a metalloligand (using S1 and S4) to the [FeCp*(CO)]+ fragment, where (L′)2− is [S—C(Me)=C(Me)—S—(CH2)3—S—C(Me)=C(Me)—S]2− and where Cp*− is cyclo-C5(Me)5 − (pentamethylcyclopentadienyl). The ratio of hexafluorophosphate anion per complex cation is 1:1. The structure at 150 K has orthorhombic (Pbcn) symmetry. The atoms of the complex cation are located on general positions (multiplicity = 8), whereas there are two independent hexafluorophosphate anions, each located on a twofold axis (Wyckoff position 4c; multiplicity = 4). The structure of the new dimetallic cation [Ni(L′)FeCp*(CO)]+ can be described as containing a three-legged piano-stool environment for iron [Cp*Fe(CO)`S2'] and an approximately square-planar `S4' environment for Ni. The NiS2Fe diamond-shaped substructure is notably folded at the S—S hinge: the angle between the NiS2 plane and the FeS2 plane normals is 64.85 (6)°. Largely because of this fold, the nickel–iron distance is relatively short, at 2.9195 (8) Å. The structural data for the complex cation, which contains a new unsaturated `S4' ligand (two C=C double bonds), provide an interesting comparison with the known NiFe hydrogenase models containing a saturated `S4'-ligand analogue having the same number of carbon atoms in the ligand backbone, namely with the structures of [Ni(L)FeCp(CO)]+ (as the PF6 − salt, CH2Cl2 solvate) and [Ni(L)FeCp*(CO)]+ (as the PF6 − salt), where (L)2− is [S—CH2—CH2—S—(CH2)3—S—CH2—CH2—S]2− and Cp− is cyclopentadienyl. The saturated analogues [Ni(L)FeCp(CO)]+ and [Ni(L)FeCp*(CO)]+ have similar Ni—Fe distances: 3.1727 (6), 3.1529 (7) Å (two independent molecules in the unit cell) and 3.111 (5) Å, respectively, for the two complexes, whereas [Ni(L′)FeCp*(CO)]+ described here stands out with a much shorter Ni—Fe distance [2.9196 (8) Å]. Also, [Ni(L)FeCp(CO)]+ and [Ni(L)FeCp*(CO)]+ show interplanar fold angles that are similar between the two: 39.56 (5), 41.99 (5) (independent molecules in the unit cell) and 47.22 (9) °, respectively, whereas [Ni(L′)FeCp*(CO)]+ possesses a much more pronounced fold [64.85 (6)°]. Given that larger fold angles and shorter Ni—Fe distances are considered to be structurally closer to the enzyme, unsaturation in an `S4'-ligand of the type (S—C2—S—C3—S—C2—S)2− seems to increase structural resemblance to the enzyme for structural models of the type [Ni(`S4')FeCp R (CO)]+ (Cp R = Cp or Cp*).

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40

Thị Hue, Nguyen, Nguyen Van Hop, Hoang Thai Long, Nguyen Hai Phong, Tran Ha Uyen, Le Quoc Hung, and Nguyen Nhi Phuong. "Determination of Chromium in Natural Water by Adsorptive Stripping Voltammetry Using In Situ Bismuth Film Electrode." Journal of Environmental and Public Health 2020 (May 14, 2020): 1–15. http://dx.doi.org/10.1155/2020/1347836.

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Development of adsorptive stripping voltammetry (AdSV) combined with in situ prepared bismuth film electrode (in situ BiFE) on glassy carbon disk surface using diethylenetriamine pentaacetic acid (DTPA) as a complexing agent and NO3− as a catalyst to determine the trace amount of chromium (VI) is demonstrated. According to this method, in the preconcentration step at Edep = −800 mV, the bismuth film is coated on the surface of glassy carbon electrodes simultaneously with the adsorption of complexes Cr(III)-DTPA. In addition to the influencing factors, the stripping voltammetry performance factors such as deposition potential, deposition time, equilibration time, cleaning potential, cleaning time, and technical parameters of differential pulse and square wave voltammetries have been investigated, and the influence of Cr(III), Co(II), Ni(II), Ca(II), Fe(III), SO42−, Cl−, and Triton X has also been investigated. This method gained good repeatability with RSD <4% (n = 9) for the differential pulse adsorptive stripping voltammetry (DP-AdSV) and RSD < 3% (n = 7) for the square wave adsorptive stripping voltammetry (SqW-AdSV), and low limit of detection: LOD = 12.10−9 M ≈ 0.6 ppb (at a deposition potential (Edep) of −800 mV and the deposition time (tdep) of 50 s) and LOD = 2.10−9 M ≈ 0.1 ppb (at Edep = −800 mV and tdep = 160 s) for the DP-AdSV and SqW-AdSV, respectively. This method has been successfully applied to analyze chromium in natural water.

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41

H. Sumrra, S., M. Anees, A. Asif, M. N. Zafar, K. Mahmood, M. F. Nazar, M. Khalid, M. A. Nadeem, and M. U. Khan. "Synthesis, structural, spectral and biological evaluation of metals endowed 1,2,4-triazole." Bulletin of the Chemical Society of Ethiopia 34, no. 2 (October 28, 2020): 335–51. http://dx.doi.org/10.4314/bcse.v34i2.11.

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Biologically active triazole Schiff base ligand 2,4-dichloro-6-[(1H-1,2,4-triazol-3-ylimino)methyl]phenol (A) has been synthesized by the condensation reaction of an equimolar amount of 1H-1,2,4-triazole-3-amine and 3,5-dichlorosalicylaldehyde and then it coordinated with salts of metals [VO(IV), Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)] in 2:1 molar ratio to derive a series of transition metal chelates (1)-(6). All the compounds were characterized by various physical, spectral, analytical techniques and elemental analysis. Spectral characterization and magnetic moment data of complexes revealed square pyramidal geometry for vanadium complex and octahedral for remaining (2)-(6) complexes. Quantum chemical calculation has been carried out to explore optimized geometry and electronic structure of the ligand. Density functional theory (DFT) with B3LYP/6-311+g(d,p) method was performed to determine vibrational bands, frontier molecular orbitals (FMOs) and natural bond analysis (NBO) of the ligand. NBO analysis showed that the ligand bears higher molecular stability because of hyper conjugate interactions. Computational study results revealed that there was a close interaction of theoretical and experimental spectroscopic data. Global reactivity descriptors calculated by the energies of FMOs, indicated ligand to be bioactive. The synthesized compounds were studied for antibacterial, antifungal, antioxidant and antiglycation activity and the results revealed that ligand has remarkable activity which considerably increased upon chelation. KEY WORDS: Triazole ligand, Transition metal chelates, Antibacterial, Antifungal, Antioxidant, Computational study Bull. Chem. Soc. Ethiop. 2020, 34(2), 335-351 DOI: https://dx.doi.org/10.4314/bcse.v34i2.11

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42

Cullen, William R., Steven J. Rettig, and Tu Cai Zheng. "Preparation and characterization of the osmium cluster complexes H2Os3(CO)8L(EtFcPCMe) (L = CO or PEt2Fc) and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)]." Canadian Journal of Chemistry 71, no. 3 (March 1, 1993): 399–409. http://dx.doi.org/10.1139/v93-059.

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Thermolysis of Os3(CO)11(PEt2Fc) (Fc = (η-C5H4)Fe(η-C5H5)) in octane for 8 h affords H2Os3(CO)9(EtFcPCMe), 10, and H2Os3(CO)8[(η-C5H3PEt2)Fe(η-C5H4)], 9e, in 15 and 65% yield, respectively. Heating Os3(CO)12 and PEt2Fc in 1:2 molar ratio in xylene for 10 h gives two isomers of H2Os3(CO)8(PEt2Fc)(EtFcPCMe), 11, in about 40% yield. Two crystalline modifications of the complex 9e have been obtained from the same solvent: 9eA, triclinic, a = 15.653(1), b = 15.799(1), c = 11.257(1) Å, α = 90.388(7)°, β = 109.740(6)°, γ = 82.445(6)°, Z = 4 (two molecules per asymmetric unit), space group [Formula: see text]; and 9eB, monoclinic, a = 9.889(2), b = 13.632(3), c = 18.927(4) Å, β = 97.36(2)°, Z = 4, space group P21/n. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.033 and 0.037 for 8131 and 5145 reflections with I ≥ 3σ(I), respectively.

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43

Belani, Ramesh M., Brian R. James, David Dolphin, and Steven J. Rettig. "Catalytic decarbonylation of aldehydes using iron(II) porphyrin complexes, and the crystal structure of (5,10,15,20-tetraphenylporphinato)bis(tri-n-butylphosphine)iron(II)." Canadian Journal of Chemistry 66, no. 8 (August 1, 1988): 2072–78. http://dx.doi.org/10.1139/v88-332.

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The complex (5, 10, 15, 20-tetraphenylporphinato)bis(tri-n-butylphosphine)iron(II), 1, has been isolated in a triclinic crystal form, a = 12.499(3), b = 12.528(2), c = 12.039(2) Å, α = 116.39(1), β = 109.79(1), γ = 98.13(1)°, Z = 1, space group [Formula: see text]. The structure was solved by conventional heavy atom methods and was refined by full-matrix least-squares procedures to R = 0.060 and Rw = 0.070 for 3551 reflections with I ≥ 3σ(I). The molecule, which has crystallographic [Formula: see text], symmetry, displays a relatively undistorted pseudo-octahedral coordination geometry with Fe—P = 2.346(1) and Fe—N = 1.998(3) and 1.993(3) Å. In CH2Cl2 solution, 1 reacts with CO and aldehydes to generate the carbonyl(phosphine) derivative, and decarbonylation of phenylacetaldehyde to toluene becomes catalytic under an Ar stream. The aldehyde decarbonylations involve radical pathways via carbonyl loss from [Formula: see text]. The hydrogen abstraction/initiation reaction probably utilizes trace O2 (and possibly trace (water); speculative mechanisms are discussed.

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44

Cullen, William R., Steven J. Rettig, and Tu Cai Zheng. "Crystal and molecular structures of two triosmium carbonyl cluster complexes containing ortho-metalated phenylphosphines (μ-H)Os3(CO)8L[PFcPh(C6H4)] (L = PFcPh2 or CO)." Canadian Journal of Chemistry 70, no. 8 (August 1, 1992): 2215–23. http://dx.doi.org/10.1139/v92-278.

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Pyrolysis of Os3(CO)11(PFcPh2), 7, and Os3(CO)10(PFcPh2)2, 8, (FcH = (Fe(η-C5H5)2 affords (μ-H)Os3(CO)9[PFcPh(C6H4)], 5, and (μ-H)Os3(CO)8(FcPPh2)[PFcPh(C6H4)], 6, respectively. The structures of 5 and 6 are analogous; they both contain a bridging hydride and a μ3-PFcPh(C6H4) moiety resulting from the ortho-metalation of one phenyl group and subsequent formation of a η2-bond from that metalated phenyl to the third osmium atom. Crystals of 5, are triclinic, a = 11.380(2), b = 15.930(3), c = 9.467(1) Å, α = 92.82(1)°, β = 100.32(1)°, 7 = 71.55(1)°, Z = 2, space group [Formula: see text], and those of 6•CH2Cl2, are also triclinic, a = 13.151(3), b = 17.177(4), c = 12.619(3) Å, α = 91.98(2)°, β = 104.18(2)°, γ = 67.72(2)°, Z = 2, space group [Formula: see text]. The structures were solved by heavy atom methods and were refined by full-matrix least-squares procedures to R = 0.028 and 0.026 by using 8080 and 9336 reflections with I ≥ 3σ(I), respectively.

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45

O’Hanlon, James A., Robert D. Chapman, Frank Taylor, and Melissa A. Denecke. "Quantification of common aminopolycarboxylic acids in trench leachate from the Low Level Waste Repository." Journal of Radioanalytical and Nuclear Chemistry 322, no. 3 (November 11, 2019): 1915–29. http://dx.doi.org/10.1007/s10967-019-06895-x.

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Abstract The aminopolycarboxylic acids (APCAs), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA) and nitrilotriacetic acid (NTA), are used as decontamination agents throughout the nuclear industry; therefore, APCAs are often found in radioactive waste. Limits of acceptance on APCAs are imposed on wastes consigned to the Low Level Waste Repository (LLWR) because, when present in the waste, the ligands have the potential to mobilise otherwise surface-bound or solid radionuclides, making them available for transport to groundwater and ultimately to the bio-sphere. A selective and sensitive methodology to detect and quantify these ligands in a range of complex matrices is advantageous in supporting waste acceptance processes. A reversed-phase high-performance liquid chromatography (HPLC) procedure has been applied for quantification of EDTA, DTPA and NTA in their Fe(III)-complex form. Method validation results show linearity (r2 > 0.999), precision (intra/inter-day %RSD ≤ 10%), accuracy (recovery = 100 ± 3%), sensitivity (minimum limits of detection = 0.31, 0.38 and 4.3 μM for EDTA, DTPA and NTA, respectively) and selectivity (simultaneous determination of the three APCA complexes achieved with baseline resolution) for Fe(III)-APCAs in aqueous solution. Chromatographic peak overlap is observed for samples containing Fe(III)- and Co(III)-EDTA; two deconvolution methods (2D least-squares fitting vs. PARAFAC) were applied to resolve the peaks and the performances compared. The optimised HPLC method was applied to trench leachate samples from the LLWR site. EDTA was detected with 0.4 μM < concentrations < 1 μM in samples from four of the six sampling locations tested. The levels are not considered sufficient to increase the risk of radionuclide mobilisation. The technique is considered to be robust and will be considered further in informing limits of acceptance on APCAs.

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46

Shaker, Shayma, Hamid Khaledi, and Hapipah Ali. "Spectroscopic investigations and physico-chemical characterization of newly synthesized mixed-ligand complexes of 2-methylbenzimidazole with metal ions." Chemical Papers 65, no. 3 (January 1, 2011). http://dx.doi.org/10.2478/s11696-011-0003-8.

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AbstractSome mixed ligand complexes containing 2-methylbenzimidazole and thiocyanate ion were synthesized. Free ligands and their metal complexes were characterized using elemental analysis, determination of metal, magnetic susceptibility, molar conductivity, infrared, UV-VIS, and (1H, 13C) NMR spectra, and X-ray structure analysis. The results suggest that the Ag(I) complex has linear geometry, Fe(II), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) have tetrahedral geometry, Pd(II) complex has square planar geometry, VO(IV) square pyramidal geometry, Pb(II) irregular tetrahedral geometry, and that the Cr(III) and Mn(II) complexes have octahedral geometry. The following general formulae were proposed for the prepared complexes: [AgBX], [CrB3X3], (HB)2[MnB2X4] · 2B and [MB2X2], where B = 2-methylbenzimidazole, HB = 2-methylbenzimidazolium, X = thiocyanate ion, and M = VO(IV), Fe(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Cd(II), and Pb(II). Molar conductance of a 10−3 M solution in N,N-dimethyl formamide (DMF) indicates that all the complexes are non-electrolytes except the Mn(II) complex which is an electrolyte because the molar conductivity of its solution in DMF is high.

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47

SOĞUKÖMEROĞULLARI, Hatice Gamze, and Eyüp BAŞARAN. "Synthesis and Characterization of New Hydrazone Derivatives Fe(II), Co(II), Ni(II) and Cu(II) Complexes." Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi, August 20, 2022, 216–22. http://dx.doi.org/10.19113/sdufenbed.1031209.

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N-((2-hydroxynaphthalen-1-yl)methylene)nicotinohydrazide ligand derived from the condensation reaction of 2-hydroxynaphthaldehyde and nicotinic hydrazide was obtained. New hydrazone metal complexes L2Fe, L2Co, L2Ni and L2Cu2 were synthesized from the reaction of N-((2-hydroxynaphthalen-1-yl)methylene)nicotinohydrazide ligand and Fe(II), Co(II), Ni(II) and Cu(II) acetate salts in a 2:1 stoichiometric ratio, respectively. The synthesized compounds were characterized by techniques such as FT-IR, NMR (ligand only), UV-Vis, elemental analysis, molar conductivity measurement, magnetic susceptibility. Magnetic susceptibility measurements were recorded as 5.96 BM, 1.03 BM, 1.08 BM and 1.61 BM for the L2Fe, L2Co L2Ni and L2Cu2 complexes, respectively. It has been determined that the L2Cu2, L2Ni and L2Co complexes have antiferromagnetic properties. The L2Fe, L2Co and L2Ni complexes have octahedral geometry, while the L2Cu2 complex has a square plane geometry. The molar conductivity values of the complexes are between 1.31-2.61 μS/cm and do not have conductivity properties.

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48

"Synthesis and Optical Studies of the 3,4-dimethoxy Benzaldehyde [5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]Hydrazone Metal Complexes." University of Thi-Qar Journal of Science, December 7, 2020, 95–100. http://dx.doi.org/10.32792/utq/utjsci/vol7/2/22.

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The aim of the present study is to synthesize and optical studies of 3,4-dimethoxy benzaldehyde [5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl]hydrazone metal complexes. Firstly, the 3,4-dimethoxybenzaldehyde [5-(2-hydroxyphenyl)-1,3,4-oxadiazol-2-yl] hydra zone was synthesized by the reaction of the 2-(5-hydrazino-1,3,4-oxadiazol-2-yl)phenol with 2,3-dimethoxybenzaldehyde in the ethanol as a solvent . Scondly, its complexes of Cr(III), Fe(III), Co(II) and Ni (II) have been synthesized. The synthesized coumpounds and its metal complexes were characterized by the FTIR, Mass spectra and UV-vis absorption. The results confirmed the suggested square planar geometry of the Ni (II) complex and tetrahedral geometry of the Co(II) complex, while Cr (III), Fe(III) complexes were assigned octahedral geometrics. The optical absorption spectra of those complexes in the wavelength range from 200-900 nm were studied.The results showed that the optical absorption is due to indirect allowed transitions of the compound and its complexes, the energy gap (Eg) of these compounds decreases in the order L> Ni (II)> Fe(III)> Co(II) and > Cr(III), the absorption coefficient (α), real and imaginary parts (ɛr,ɛi), and optical conductivity (σopt)were estimated.

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49

AGBO, N. J., and P. O. UKOHA. "SYNTHESISAND ANTIMICROBIAL STUDIES OF SCHIFF BASE DERIVED FROM2-THENOYLTRIFLUOROACETONE AND 4-AMINOANTIPYRINEAND ITSCo(II), Fe(III), Ni(II) AND Cu(II) COMPLEXES." Journal of Chemical Society of Nigeria 48, no. 4 (August 23, 2023). http://dx.doi.org/10.46602/jcsn.v48i4.902.

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A new ligand, 3-[2-(1, 5-dimethyl-3-oxo-2-phenyl-2, 3-dihydro-1H-pyrazol-4-yl) hydrazinylidene]-2-thenoyltrifluoroacetone (HPDP) was prepared by diazotization of 4-aminoantipyrine and coupling of the obtained diazonium salt with 2-thenoyltrifluoroacetone. It’s Co(II), Fe(III), Cu(II), Ni(II) complexes were synthesized by refluxing the ligand(HPDP) with the metal chlorides in absolute ethanol for 6 hrs. Obtained compounds were characterized by means of melting point, conductivity, elemental analysis UV-Visible, FT-IR, 1H and 1 3C NMR.The molar conductivity values indicated that,[Fe(PDP)(H2O)Cl2], [Co(PDP)Cl2(OH2)], [Cu(HPDP)Cl2], [Ni(PDP)Cl2(OH2)] complexes were electrolytes when compared with CuSO4 and KCl salts respectively. The chloride analysis determination revealed the presence of chloride ions inside the coordination sphere of all the complexes. The Uv-Vis, IR, 1H and 13CNMR data of the complexes suggest square-planar geometry around Co (II), Cu (II), Ni (II) and octahedral geometry around Fe (III) ions. The ligand is tridentate and the complexes crystalized as M (HPDP). The ligand coordinated through the carbonyl oxygens and nitrogen atom of the azomethine –C=N group. The antimicrobial screening of the ligand and complexes with B.subtilis, E.coli, and P.mirabilis,S. aureus, S. intermediusS. typhi and S. pneumoniae showed more activities for the complexes than the ligand in comparison with standard drugs (Ampicillin and Ciprofloxacin), this implies that the synthesized compounds have potency for possible use as antbacterial agents against resistant strains.

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50

Al-Mohammadi, Noor Al-Huda A. H., Aeed S. M. Al-Fahdawi, and Sattar S. I. Al-Janabi. "Design and Characterization of New Dinuclear Macrocyclic Dithiocarbamate Complexes by the Preparation of a Free Ligand Derived from Isopropylamine." Iraqi Journal of Science, January 30, 2021, 1–15. http://dx.doi.org/10.24996/ijs.2021.62.1.1.

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The synthesis and structural characterization of new dithiocarbamate (DTC) ligand and some of its dinuclear transition metal complexes are described. The free dithiocarbamate ligand was prepared through several synthetic routes, including Schiff-base formation. The reaction of 2-aminopropane with terephthaldehyde leads to the formation of Schiff_base which is reduced by methanolic NaBH4 to the corresponding secondary diamine. Diamine( N,N'_ (1,4 phenylenebis (methylene)) bis(propan-2 amine)) reacts with (CS2) in a basic solution of (KOH) to provide the corresponding bis(dithiocarbamate) free_ligand, which undergoes complexation with the appropriate metal (II) chloride to constitute macrocyclic complexes. Characterization of the ligand and its complexes was achieved by FTIR, UV-Vis, melting points, conductance, magnetic susceptibility, and 1H, 13C NMR spectroscopy. The analytical and spectroscopic data were employed to obtain the suggested geometries around metal centres. These studies revealed the formation of dinuclear macrocyclic complexes of the general formula [M(L)]2 (where M= Mn(II) , Fe(II), Co(II), Ni(II), Cu(II) and Zn(II)), with tetrahedral. geometries for Mn(II) , Fe(II), Co(II) and Zn(II), and square. planar geometry with Ni(II) and Cu(II) complexes.

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Journal articles on the topic 'Fe-Co square complexes'

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