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Journal articles on the topic 'Complexes de cobalt(III)'

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Published: 29 March 2025

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1

Ali Mohamed, Ahmed Y. "STUDIES ON THE BACTERIAL ACTIVITY OF COBALT(III) COMPLEXES. PART III. COBALT(III) CARBOXYLATE COMPLEXES." Journal of Coordination Chemistry 29, no. 4 (August 1993): 233–46. http://dx.doi.org/10.1080/00958979308037429.

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2

Mohamed, Ahmed Y. Ali. "STUDIES ON THE BACTERIAL ACTIVITY OF COBALT(III) COMPLEXES. PART III. COBALT(III) CARBOXYLATE COMPLEXES." Journal of Coordination Chemistry 29, no. 3 (July 1993): 233–46. http://dx.doi.org/10.1080/00958979308045670.

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3

Arderne, Charmaine, Kyle Fraser Batchelor, Bhawna Uprety, Rahul Chandran, and Heidi Abrahamse. "Reactivity trends of cobalt(III) complexes towards various amino acids based on the properties of the amino acid alkyl chains." Acta Crystallographica Section C Structural Chemistry 76, no. 7 (June 5, 2020): 663–72. http://dx.doi.org/10.1107/s2053229620007123.

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The reactivity of the cobalt(III) complexes dichlorido[tris(2-aminoethyl)amine]cobalt(III) chloride, [CoCl2(tren)]Cl, and dichlorido(triethylenetetramine)cobalt(III) chloride, [CoCl2(trien)]Cl, towards different amino acids (L-proline, L-asparagine, L-histidine and L-aspartic acid) was explored in detail. This study presents the crystal structures of three amino acidate cobalt(III) complexes, namely, (L-prolinato-κ2 N,O)[tris(2-aminoethyl)amine-κ4 N,N′,N′′,N′′′]cobalt(III) diiodide monohydrate, [Co(C5H8NO2)(C6H18N4)]I2·H2O, I, (L-asparaginato-κ2 N,O)[tris(2-aminoethyl)amine-κ4 N,N′,N′′,N′′′]cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), II, and (L-prolinato-κ2 N,O)(triethylenetetramine-κ4 N,N′,N′′,N′′′)cobalt(III) chloride perchlorate, [Co(C4H7N2O3)(C6H18N4)](Cl)(ClO4), V. The syntheses of the complexes were followed by characterization using UV–Vis spectroscopy of the reaction mixtures and the initial rates of reaction were obtained by calculating the slopes of absorbance versus time plots. The initial rates suggest a stronger reactivity and hence greater affinity of the cobalt(III) complexes towards basic amino acids. The biocompatibility of the complexes was also assessed by evaluating the cytotoxicity of the complexes on cultured normal human fibroblast cells (WS1) in vitro. The compounds were found to be nontoxic after 24 h of incubation at concentrations up to 25 mM.

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4

Salib, Kamal A. R., Samy M. Abu El-Wafa, Salah B. El-Maraghy, and Saied M. El-Sayed. "Sulfitoamine Complexes of Cobalt(III)." Phosphorus, Sulfur, and Silicon and the Related Elements 46, no. 3-4 (December 1989): 131–38. http://dx.doi.org/10.1080/10426508909412058.

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5

Massoud, Salah S., Franz A. Mautner, Morsy Abu-Youssef, and Nadia M. Shuaib. "Azido–amine–cobalt(III) complexes." Polyhedron 18, no. 17 (July 1999): 2287–91. http://dx.doi.org/10.1016/s0277-5387(99)00106-0.

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6

Lindner, Leonie, and Peter Klüfers. "Cobalt(III) Complexes ofD-Galactosylamine." Zeitschrift für anorganische und allgemeine Chemie 641, no. 11 (July 14, 2015): 1869–73. http://dx.doi.org/10.1002/zaac.201500224.

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7

Veeralakshmi, Selvakumar, Selvan Nehru, Gopal Sabapathi, Sankaralingam Arunachalam, Ponnambalam Venuvanalingam, Ponnuchamy Kumar, Chidambaram Anusha, and Vilwanathan Ravikumar. "Single and double chain surfactant–cobalt(iii) complexes: the impact of hydrophobicity on the interaction with calf thymus DNA, and their biological activities." RSC Advances 5, no. 40 (2015): 31746–58. http://dx.doi.org/10.1039/c5ra02763b.

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8

Alam, M. M., S. M. S. Islam, S. M. M. Rahman, and M. M. Rahman. "Simultaneous Preparation of Facial and Meridional Isomer of Cobalt-Amino Acid Complexes and their Characterization." Journal of Scientific Research 2, no. 1 (December 29, 2009): 91–98. http://dx.doi.org/10.3329/jsr.v2i1.2032.

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Preparation and characterization of various complexes of cobalt (III)-amino acid system, especially cobalt (III) glycinato and cobalt (III) alaninato complexes are reported. The identification of the various isomers of these complexes is also reported. The various isomers are separated from their mixture by fractional crystallization. Each of these complexes has been characterized by observing physical characteristics, chemical analysis, UV-visible spectroscopy and IR-spectroscopy. The direct impact of geometry of the complexes to IR stretching frequencies and UV-visible spectral data of amino and carboxyl group in the complexes provided sufficient information about the geometry. A prediction about the geometries of the synthesized has also been focused. Keywords: Cobalt; Amino acid; Isomers; UV-visible; IR. © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i1.2032 J. Sci. Res. 2 (1), 91-98 (2010)

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9

Uprety, Bhawna, Rahul Chandran, Charmaine Arderne, and Heidi Abrahamse. "Anticancer Activity of Urease Mimetic Cobalt (III) Complexes on A549-Lung Cancer Cells: Targeting the Acidic Microenvironment." Pharmaceutics 14, no. 1 (January 17, 2022): 211. http://dx.doi.org/10.3390/pharmaceutics14010211.

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Tumour cells maintain a local hypoxic and acidic microenvironment which plays a crucial role in cancer progression and drug resistance. Urease is a metallohydrolases that catalyses the hydrolysis of urea into ammonia and carbon dioxide, causing an abrupt increase of pH. This enzymatic activity can be employed to target the acidic tumour microenvironment. In this study, we present the anticancer activities of urease mimetic cobalt (III) complexes on A549 cells. The cells were treated with different doses of cobalt (III) complexes to observe the cytotoxicity. The change in cellular morphology was observed using an inverted microscope. The cell death induced by these complexes was analysed through ATP proliferation, LDH release and caspase 3/7 activity. The effect of extracellular alkalinization by the cobalt (III) complexes on the efficacy of the weakly basic drug, doxorubicin (dox) was also evaluated. This combination therapy of dox with cobalt (III) complexes resulted in enhanced apoptosis in A549 cells, as evidenced by elevated caspase 3/7 activity in treated groups. The study confirms the urease mimicking anticancer activity of cobalt (III) complexes by neutralizing the tumour microenvironment. This study will motivate the applications of transition metal-based enzyme mimics in targeting the tumour microenvironment for effective anticancer treatments.

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10

Ali-Mohamed, Ahmed Y., and M. �l-Khedri. "Studies on the bacterial activity of cobalt(III) complexes. Part I. Cobalt(III) amine complexes." Transition Metal Chemistry 13, no. 6 (December 1988): 434–36. http://dx.doi.org/10.1007/bf01043705.

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11

Ali-Mohamed, Ahmed Y., and Abdulla A. R. Abdulla. "Studies on the bacterial activity of cobalt(III) complexes. Part II. Cobalt(III) aminoacidato-complexes." Transition Metal Chemistry 14, no. 3 (June 1989): 181–84. http://dx.doi.org/10.1007/bf01043790.

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12

Nikovskii, I. A., D. A. Babakina, G. L. Denisov, Yu V. Nelyubina, and E. A. Khakina. "Study of the Reduction of Cobalt(III) Complexes by In Situ NMR Spectroscopy." Координационная химия 49, no. 1 (January 1, 2023): 27–35. http://dx.doi.org/10.31857/s0132344x22700037.

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An approach for monitoring the redox activation of drug delivery in cobalt(III) complexes by in situ NMR spectroscopy is proposed. The reduction of the heteroleptic cobalt(III) complexes containing the 6,7-dihydroxycoumarin molecule applied as a model drug is studied using the proposed approach. The replacement of the bipyridine ligand in the cobalt(III) complex by phenanthroline considerably increases the redox-activated release rate of the drug.

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13

Fang, Jiaxin, Philipp Gerschel, Kuldip Singh, Ulf-Peter Apfel, and Kogularamanan Suntharalingam. "Cobalt(III)–Macrocyclic Scaffolds with Anti-Cancer Stem Cell Activity." Molecules 29, no. 12 (June 8, 2024): 2743. http://dx.doi.org/10.3390/molecules29122743.

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Cobalt(III) compounds with tetradentate ligands have been widely employed to deliver cytotoxic and imaging agents into cells. A large body of work has focused on using cobalt(III)–cyclam scaffolds for this purpose. Here, we investigate the cytotoxic properties of cobalt(III) complexes containing 14-membered macrocycles related to cyclam. A breast cancer stem cell (CSC) in vitro model was used to gauge efficacy. Specifically, [Co(1,4,7,11-tetraazacyclotetradecane)Cl2]+ (1) and [Co(1-oxa-4,8,12-triazacyclotetradecane)Cl2]+ (2) were synthesised and characterised, and their breast CSC activity was determined. The cobalt(III) complexes 1 and 2 displayed micromolar potency towards bulk breast cancer cells and breast CSCs grown in monolayers. Notably, 1 and 2 displayed selective potency towards breast CSCs over bulk breast cancer cells (up to 4.5-fold), which was similar to salinomycin (an established breast CSC-selective agent). The cobalt(III) complexes 1 and 2 were also able to inhibit mammosphere formation at low micromolar doses (with respect to size and number). The mammopshere inhibitory effect of 2 was similar to that of salinomycin. Our studies show that cobalt(III) complexes with 1,4,7,11-tetraazacyclotetradecane and 1-oxa-4,8,12-triazacyclotetradecane macrocycles could be useful starting points for the development of new cobalt-based delivery systems that can transport cytotoxic and imaging agents into breast CSCs.

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14

Hanack, Michael, and Carola Hedtmann-Rein. "Elektrisch leitfähiges μ-Cyano(tetrabenzoporphyrinato)cobalt(III)/ Electric Conductive Electric Conductive //-Cyano(tetrabenzoporphyrinato)cobalt(III)-Cyano(tetrabenzoporphyrinato)cobalt(III)." Zeitschrift für Naturforschung B 40, no. 8 (August 1, 1985): 1087–89. http://dx.doi.org/10.1515/znb-1985-0817.

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AbstractThe preparation of tetrabenzoporphyrinatocobalt(II) and tetrabenzoporphyrinatocobalt(III)- cyanide derivatives either with terminal or bridging cyanide is described. The IR and the 1H NMR spectra as well as magnetic measurements are in accordance with the proposed structures and the oxidation states of the complexes. μ-Cyano(tetrabenzoporphyrinato)cobalt(III) (4) exhibits a powder conductivity of σRT = 4 ·10-2 S/cm, without additional external doping.

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15

Emara, Adel A. A., Faten S. M. Abd El-Hameed, and Saied M. E. Khalil. "TELLURITO COMPLEXES: MIXED LIGAND COMPLEXES OF COBALT(III)." Phosphorus, Sulfur, and Silicon and the Related Elements 112, no. 1-4 (May 1, 1996): 115–20. http://dx.doi.org/10.1080/10426509608046354.

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16

Ali-Mohamed, Ahmed Y. "Bacterial activity of cobalt(III) complexes. Part IV: Diethylenetriaminemonoacetatocobalt(III) complexes." Transition Metal Chemistry 16, no. 1 (February 1991): 14–17. http://dx.doi.org/10.1007/bf01127862.

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17

O'Neill, E. S., J. L. Kolanowski, G. H. Yin, K. M. Broadhouse, S. M. Grieve, A. K. Renfrew, P. D. Bonnitcha, and E. J. New. "Reversible magnetogenic cobalt complexes." RSC Advances 6, no. 36 (2016): 30021–27. http://dx.doi.org/10.1039/c6ra04643f.

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18

Izmesteva, V. A., and A. M. Elokhov. "EXTRACTION OF CHLORIDE AND THIOCYATE ACIDOCOMPLEXES OF METALS IN SALTING-OUT AGENT – MONOALKYLPOLYETHYLENE GLYCOL – WATER SYSTEMS." Вестник Пермского университета. Серия «Химия» = Bulletin of Perm University. CHEMISTRY 11, no. 4 (2021): 244–53. http://dx.doi.org/10.17072/2223-1838-2021-4-244-253.

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Distribution of iron (III), thallium (III, gallium, titanium (IV) chloride complexes in sodium chloride – synthanol DS-10 – water and ammonium sulfate – synthanol DS-10 – water systems, as well as iron (III), cobalt , nickel, cadmium and copper (II) thiocyanate complexes in the ammonium sulfate – synthanol DS-10 – water system investigated. It was found that the main influence on extraction is exerted by solution acidity and nature of the salting-out agent. The conditions for quantitative extraction of thallium (III) and gallium in the form of chloride complexes, as well as the conditions for maximum extraction of iron (III), zinc and cobalt thiocyanate complexes are established.

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19

Deblitz, Raik, Cristian G. Hrib, Steffen Blaurock, Peter G. Jones, Georg Plenikowski, and Frank T. Edelmann. "Explosive Werner-type cobalt(iii) complexes." Inorg. Chem. Front. 1, no. 8 (2014): 621–40. http://dx.doi.org/10.1039/c4qi00094c.

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A series of potentially explosive Werner-type cobalt(iii) complexes comprising the anions azotetrazolate, nitrotetrazolate, picrate and dipicrylamide have been prepared via simple metathetical routes. Representative studies of the energetic properties (impact and friction sensitivity, combustion) revealed that some of the new compounds are primary explosives.

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20

Brewer, John C., Terrence J. Collins, Milton R. Smith, and Bernard D. Santarsiero. "Neutral square planar cobalt(III) complexes." Journal of the American Chemical Society 110, no. 2 (January 1988): 423–28. http://dx.doi.org/10.1021/ja00210a018.

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21

Kapanadze, T. Sh, G. V. Tsintsadze, Yu V. Kokunov, and Yu A. Buslaev. "Linkage isomerism in cobalt(III) complexes." Polyhedron 9, no. 11 (January 1990): 1379–82. http://dx.doi.org/10.1016/s0277-5387(00)84019-x.

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22

Ghosh, Manik C., Prabir Bhattacharya, and Pradyot Banerjee. "Anation Reactions of Cobalt(III) complexes." Coordination Chemistry Reviews 91 (November 1988): 1–34. http://dx.doi.org/10.1016/0010-8545(88)80012-2.

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23

Delehanty, James B., Jason E. Bongard, Dzung C. Thach, D. Andrew Knight, Thomas E. Hickey, and Eddie L. Chang. "Antiviral properties of cobalt(III)-complexes." Bioorganic & Medicinal Chemistry 16, no. 2 (January 2008): 830–37. http://dx.doi.org/10.1016/j.bmc.2007.10.022.

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24

Klein, Hans-Friedrich, Stefan Haller, Hongjian Sun, Xiaoyan Li, Thomas Jung, Caroline Röhr, Ulrich Flörke, and Hans-Jürgen Haupt. "Hydrido(acylphenolato)cobaIt(III)-Verbindungen mit Trimethylphosphan-Liganden / Hydrido(acylphenolato)cobalt(III) Compounds Containing Trimethylphosphane Ligands." Zeitschrift für Naturforschung B 53, no. 5-6 (June 1, 1998): 587–98. http://dx.doi.org/10.1515/znb-1998-5-617.

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Abstract Salicylaldehyde derivatives and related β-hydroxo aldehydes CHO-CR=CR′-OH react with CoMe(PMe3)4 via oxidative substitution to form low-spin d6 complexes mer-CoH(CO-CR=CR-O)(PMe3)3. Reductive elimination of acyl and hydride functions from cis positions at the metal is less favourable than in carbonyl cobalt intermediates through a pronounced stabilization by neutral phosphane σ-donor and dianionic acylenolato chelate ligands. Reactions of the hydride complexes with iodomethane or with protic acids HX afford octahedral molecular complexes mer-CoX(CO-CR=CR′-O)(PMe3)3 (X =I, OAc) and mer-CoX(CO-CR=CR′-O)(PMe3)2 (X = OAc, O-CR′=CR-CHO) without opening of the acylenolato chelate ring.

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25

Laan, Ramon G. W., Tona Verburg, H. Th Wolterbeek, and Jeroen J. M. de Goeij. "Photodegradation of Iron(III)-EDTA: Iron Speciation and Domino Effects on Cobalt Availability." Environmental Chemistry 1, no. 2 (2004): 107. http://dx.doi.org/10.1071/en04025.

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Environmental Context. Aquatic life requires access to sufficient nutrients and trace metals in the surrounding waters. Measuring the speciation (in solution or precipitated, free ionic or complexed) of trace metals is a traditional procedure to assess the potential of waters for life. Iron, an important nutrient, is relatively insoluble, and metal–ligand complexes are required to keep the iron in solution and bioavailable. Sunlight often degrades these metal–ligand complexes, and the subsequently released iron can outcompete other (trace) metals for their ligands. A ‘domino’ effect on weaker metal–ligand complexes will occur which complicates the actual dynamic speciation and its measurements. Abstract. The effect of photodegradation of iron(iii)-EDTA on the chemical speciation of both iron and cobalt has been tested both in a simple medium and in a more complex algal growth medium. In both media, the photodegradation of iron(iii)-EDTA caused iron(iii) to be released as a free ionic species. Released iron(iii) could be modelled as engaged in precipitation and in competition with cobalt, initially also bound to EDTA. Cobalt appeared as free ionic species after a certain lag. The length of this lag phase was proportional to the amount of EDTA added to the media, which indicated that the surplus of EDTA was first targetted by iron(iii)-EDTA photodegradation, after which iron(iii) out-competed cobalt for the EDTA in the metal–EDTA pool. All data were fitted, using a model on speciation kinetics for cobalt-EDTA and iron(iii)-EDTA, taking into account photodegradation rates of iron(iii)-EDTA and precipitation of free iron(iii). The modelled rate of iron(iii)-EDTA photodegradation was compared to direct HPLC measurements of the disappearance of iron(iii)-EDTA due to photodegradation, the latter, however, with a different iron(iii)-EDTA concentration regime. The results suggest that photodegradation is a complex process which is greatly influenced by experimental conditions (e.g. light intensity/spectrum, iron(iii), and EDTA concentrations). Iron(iii)-desferrioxamine B (DFO-B) was suggested as a possible alternative for EDTA in experimental media: photostability was shown for prolonged experimental periods.

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26

Geisenberger, Josef, Jürgen Erbe, Jürgen Heidrich, Ulrich Nagela, and Wolfgang Beck. "Pseudohalogenometallverbindungen, LXV [1] Synthese von Tetrazolen und Triazolen über die 1,3-dipolare Cycloaddition an die Azid-Liganden von polymeren Cobalt(III)-und Palladium(II)-Komplexen. Darstellung und Struktur von 5-TrichlormethyItetrazol / Pseudohalogeno Metal Compounds, LXV [1] Synthesis of Tetrazoles and Triazoles via 1,3-Dipolar Cycloaddition to the Azido Ligands of Polymerie Cobalt(III) and Palladium(II) Complexes. Synthesis and Structure of 5-Trichloromethyltetrazole." Zeitschrift für Naturforschung B 42, no. 1 (January 1, 1987): 55–64. http://dx.doi.org/10.1515/znb-1987-0112.

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Abstract The cycloaddition of nitriles and of dimethylacetylenedicarboxylate to the azide ligand of polymeric Schiff Base cobalt(III) and phosphine palladium(II) complexes gives the corresponding tetrazolate and triazolate complexes from which the heterocycles could be cleaved by hydrogen chloride. Usually the yields are low; if the heterocycle is soluble in ether or sublimable, yields up to 30% have been obtained. Using this method the hitherto unknown 5-trichlormethyltetrazole could be prepared which was characterized by an X-ray structural analysis. Similarly, the cyclo-addition of azido(tetraphenylporphinato)cobalt(III) with nitriles, cyclohexylisocyanide and MeO2CC≡CCO2 Me affords the corresponding complexes with heterocyclic ligands. The prepa-ration of tetraphenylporphyrinato(tricyanmethanido)cobalt(III), (TPP)CoN=CC(CN)2 , is reported.

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27

Sudhakar, Kolanu, Atif Mahammed, Natalia Fridman, and Zeev Gross. "Iodinated cobalt corroles." Journal of Porphyrins and Phthalocyanines 21, no. 12 (December 2017): 900–907. http://dx.doi.org/10.1142/s108842461750095x.

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Cobalt(III) complexes of selectively [Formula: see text]-pyrrole-iodinated corroles were prepared and characterized for the first time. X-ray crystallographic data reveals that the corrole macrocycle remains quite planar despite of the presence of multiple iodine substituents. The redox potentials increase linearly with the number of iodine substituents, much more for reduction than for oxidation, in a similar pattern to that of previously reported gold(III), gallium(III), and aluminum(III) complexes of [Formula: see text]-pyrrole-iodinated corroles. Their effect on reduction potential is much larger than what is observed for analogous gallium(III) and aluminum(III) corroles, wherein the chelated element is not redox active. Interestingly, the effect of iodine is similar to that of the much more electronegative halides, which is attributed to a stronger [Formula: see text]-back donation by the latter. One advantage of achieving selective iodination, in terms of the number and positioning, is that is provides an entry to further functionalization of the corrole skeleton via nucleophilic aromatic substitution.

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28

Djordjevic, Ivana, Jelena Vukasinovic, Tamara Todorovic, Nenad Filipovic, Marko Rodic, Alekandar Lolic, Gustavo Portalone, Mario Zlatovic, and Sonja Grubisic. "Synthesis, structures and electronic properties of Co(III) complexes with 2-quinolinecarboxaldehyde thio- and selenosemicarbazone: A combined experimental and theoretical study." Journal of the Serbian Chemical Society 82, no. 7-8 (2017): 825–39. http://dx.doi.org/10.2298/jsc170412062d.

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Cobalt(III) complexes derived from thio- and selenosemicarbazone ligands have been studied to elucidate the nature and consequences of S to Se substitution on their possible biological activity. Solid state structures of cobalt(III) complexes with bis-tridentate coordinated 2-quinolinecarboxaldehyde thio- and selenosemicarbazone were determined by single crystal X-ray diffraction analysis. The complexes were also characterized by spectroscopic methods and cyclic voltammetry. Electronic properties of the complexes were studied using DFT and TD?DFT methods. Finally, evident in vitro antioxidant activity of the complexes was demonstrated.

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29

Nishiura, Toshiki, Takehiro Ohta, Takashi Ogura, Jun Nakazawa, Masaya Okamura, and Shiro Hikichi. "The Conversion of Superoxide to Hydroperoxide on Cobalt(III) Depends on the Structural and Electronic Properties of Azole-Based Chelating Ligands." Molecules 27, no. 19 (September 28, 2022): 6416. http://dx.doi.org/10.3390/molecules27196416.

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Conversion from superoxide (O2‒) to hydroperoxide (OOH‒) on the metal center of oxygenases and oxidases is recognized to be a key step to generating an active species for substrate oxidation. In this study, reactivity of cobalt(III)-superoxido complexes supported by facially-capping tridentate tris(3,5-dimethyl-4-X-pyrazolyl)hydroborate ([HB(pzMe2,X)3]‒; TpMe2,X) and bidentate bis(1-methyl-imidazolyl)methylborate ([B(ImN-Me)2Me(Y)]‒; LY) ligands toward H-atom donating reagent (2-hydroxy-2-azaadamantane; AZADOL) has been explored. The oxygenation of the cobalt(II) precursors give the corresponding cobalt(III)-superoxido complexes, and the following reaction with AZADOL yield the hydroperoxido species as has been characterized by spectroscopy (UV-vis, resonance Raman, EPR). The reaction of the cobalt(III)-superoxido species and a reducing reagent ([CoII(C5H5)2]; cobaltocene) with proton (trifluoroacetic acid; TFA) also yields the corresponding cobalt(III)-hydroperoxido species. Kinetic analyses of the formation rates of the cobalt(III)-hydroperoxido complexes reveal that second-order rate constants depend on the structural and electronic properties of the cobalt-supporting chelating ligands. An electron-withdrawing ligand opposite to the superoxide accelerates the hydrogen atom transfer (HAT) reaction from AZADOL due to an increase in the electrophilicity of the superoxide ligand. Shielding the cobalt center by the alkyl group on the boron center of bis(imidazolyl)borate ligands hinders the approaching of AZADOL to the superoxide, although the steric effect is insignificant.

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30

Boyd, Simon, Kenneth P. Ghiggino, and W. David McFadyen. "Photochemistry of Anthracene-Appended Cobalt(III) Cyclam Complexes." Australian Journal of Chemistry 61, no. 8 (2008): 585. http://dx.doi.org/10.1071/ch08189.

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The photochemistry of two anthracene-appended cobalt(iii) cyclam complexes is explored with a view to demonstrate a photoactivated ligand release process. The ligand exchange processes that occur in the complexes cis-[CoL(NO2)(ONO)]+ and trans-[CoL(NO2)(ONO)]+ in which L = 6-(anthracen-9-ylmethyl)-1,4,8,11-tetraazacyclotetradecane were monitored upon illumination of the anthracenyl chromophore at 360 nm in the presence of a large excess of thiocyanate. The trans-[CoL(NO2)(ONO)]+ complex underwent a ligand exchange reaction in the absence of light and displayed an enhancement of the reaction upon illumination. In contrast the cis-[CoL(NO2)(ONO)]+ complex was stable in the dark but displayed a significant quantum yield of photoactivated ligand release (Φ = 0.19). It is proposed that in cis-[CoL(NO2)(ONO)]+ the photoexcited anthracenyl chromophore undergoes efficient energy transfer to the cobalt(iii) cyclam before ligand exchange. Complexes based on the anthracenylcyclam–cobalt(iii) framework may be potentially useful candidates as photoactivated ligand release systems.

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31

Klein, Hans-Friedrich, Stefan Haller, Hongjian Sun, Xiaoyan Li, Thomas Jung, Caroline Röhr, Ulrich Flörke, and Hans-Jürgen Haupt. "Halogeno(acylphenolato)cobalt(III)-Verbindungen mit Trimethylphosphan-Liganden/ Halogeno(acylphenolato)cobalt(III) Compounds Containing Trimethylphosphane Ligands." Zeitschrift für Naturforschung B 53, no. 8 (August 1, 1998): 856–64. http://dx.doi.org/10.1515/znb-1998-0814.

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Abstract Complexes mer-CoH(CO-CR=CR′-O)(PMe3)3 react with haloalkanes RX (X = Br, I) or with acids HX (X = Cl, Br) under elimination of dihydrogen. In both reactions a change of configuration at the metal is brought about by directional steering through the hard/soft (acyl)enolato chelate ligands to form octahedral complexes mer-CoX(CO-CR=CR′-C))(PMe3)3 or sterically crowded ionic compounds [Co(CO-CR=CR′-O)(PMe3)4(3)]+ X-(X = ClO4) without opening of the (acyl)enolato chelate ring.

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32

Aiyelabola, Temitayo, Ezekiel Akinkunmi, Isaac Ojo, Efere Obuotor, Clement Adebajo, and David Isabirye. "Syntheses, Characterization, Resolution, and Biological Studies of Coordination Compounds of Aspartic Acid and Glycine." Bioinorganic Chemistry and Applications 2017 (2017): 1–15. http://dx.doi.org/10.1155/2017/2956145.

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Enantiomerically enriched coordination compounds of aspartic acid and racemic mixtures of coordination compounds of glycine metal-ligand ratio 1 : 3 were synthesized and characterized using infrared and UV-Vis spectrophotometric techniques and magnetic susceptibility measurements. Five of the complexes were resolved using (+)-cis-dichlorobis(ethylenediamine)cobalt(III) chloride, (+)-bis(glycinato)(1,10-phenanthroline)cobalt(III) chloride, and (+)-tris(1,10-phenanthroline)nickel(II) chloride as resolving agents. The antimicrobial and cytotoxic activities of these complexes were then determined. The results obtained indicated that aspartic acid and glycine coordinated in a bidentate fashion. The enantiomeric purity of the compounds was in the range of 22.10–32.10%, with (+)-cis-dichlorobis(ethylenediamine)cobalt(III) complex as the more efficient resolving agent. The resolved complexes exhibited better activity in some cases compared to the parent complexes for both biological activities. It was therefore inferred that although the increase in the lipophilicity of the complexes may assist in the permeability of the complexes through the cell membrane of the pathogens, the enantiomeric purity of the complexes is also of importance in their activity as antimicrobial and cytotoxic agents.

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33

Selvi, M. Amutha, S. Preethi Sherina Mary, and R. Chandradevi. "Synthesis, Characterization and Structural Analysis of Cobaloximes Complexes." Asian Journal of Chemistry 34, no. 6 (2022): 1575–80. http://dx.doi.org/10.14233/ajchem.2022.23703.

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A series of bioactive cobalt(III) complexes were synthesized with bidentate ligand have been investigated as vitamin B12 models. The experiment was two pot snythesis, in the first part was green microcrystalline dihalo(dimethylglyoximato)cobalt(III) and second part was brown microcrystalline halo(pyridine based ligand) cobaloximes. Final part of synthesized complexes was characterized by IR, electronic and NMR spectral studies. Infrared spectra of metal complexes indicated the formation of Co-N axial bond and Co-N equatorial bond. Thermal analysis revealed that the Co(III) complexes were stable up to 350 ºC. The experimental results of antimicrobial were showed good zone of inhibition towards selected microbes.

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34

Creaser, II, T. Komorita, AM Sargeson, AC Willis, and K. Yamanari. "New Macrocyclic Complexes Derived From Cobalt(III) Cage Complexes." Australian Journal of Chemistry 47, no. 3 (1994): 529. http://dx.doi.org/10.1071/ch9940529.

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The synthesis and partial characterization of several green complexes, derived from the products of the reactions between [Co(Cl2-sar)]3+ (Cl2-sar = 1,8-dichloro-3,6,10,13,16,19- hexaazabicyclo [6.6.6] icosane ) and zinc powder in water, are described. Most of the complexes appear to have [CoCl2(N4)] chromophores , where N4 denotes the tetraaza macrocyclic ligand , 6,13-dimethylene-1,4,8,11-tetraazacyclotetradecane (L1). For trans-[CoCl2(L1)]+, three isomers due to different configurations about the asymmetric nitrogen donor centres were obtained and characterized by the electronic absorption and 13C n.m.r. spectra. Their stereochemistry is discussed and compared with that of 1,4,8,11-tetraazacyclotetradecane on the basis of strain energy minimized calculations. A trans-[CoCl2(H2L2)]3+ complex containing a related macrocycle with a pendant ethane-1,2-diamine arm [H2L2+, 6-(4-ammonio-2-azoniabutyl)-13-methylene-1,4,8,11-tetraazacyclotetradecane] was also isolated and characterized by X-ray crystallographic analysis. All these molecules are derived from the decomposition of zinc alkyl complexes formed by oxidative addition of zinc to the parent [CoII(Cl2-sar)]2+ ion in aqueous solution.

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35

Eaton, Donald R., and Alex O'Reilly. "Oxidation of cobalt(II) amine complexes to mononuclear cobalt(III) complexes by dioxygen." Inorganic Chemistry 26, no. 25 (December 1987): 4185–88. http://dx.doi.org/10.1021/ic00272a010.

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36

Bond, AM, R. Colton, DR Mann, and JE Moir. "Characterization of Tris(Diselenocarbamato)Cobalt(III) and Pentakis(Diselenocarbamato)Dicobalt(III) Complexes by Electrochemical, Cobalt-59 N.M.R. and Mass-Spectrometric Techniques. Comparisons With Dithiocarbamate Analogs." Australian Journal of Chemistry 39, no. 9 (1986): 1385. http://dx.doi.org/10.1071/ch9861385.

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A series of Co(RR′dsc)3 and [Co2(RR′dsc)5]+ complexes (R, R′ = two alkyl groups or one heterocyclic group; dsc = NCSe2) have been synthesized and their redox behaviour, chemical reactivity and spectroscopic properties compared with the corresponding dithiocarbamate (RR′dtc) complexes. Electrochemical oxidation of Co(RR′dsc)3 in dichloromethane at platinum electrodes occurs at potentials about 0.34 V less positive than for Co(RR′dsc)3. The formally cobalt(IV) complexes [Co(RR′dsc)3]+ can be identified as a product which is then converted into [Co2(RR′dsc)5]+ via dimerization and an internal redox reaction. Despite the enhanced thermodynamic stability implied by the redox potentials, [Co(RR′dsc)3]+ has similar kinetic stability to the analogous dithiocarbamate complexes. Co(RR′dsc)3 is reduced at fairly negative potentials on both platinum and mercury electrodes with extremely rapid loss of [RR′dsc]-. [Co(RR′dsc)3]- is therefore thermodynamically and kinetically more unstable than [Co(RR′dtc)3]- . The [Co2(RR′dsc)5]+ complexes are also more readily oxidized and harder to reduce than the sulfur analogues. Oxidation of [Co2(RR′dsc)5]+ produces [Co2(RR′dsc)5]2+ at low temperatures and fast scan rates, but no stable reduced form of the dimer is accessible on the voltammetric time scale examined. The reduction process for the dimer is consistent with the reaction [Co2(RR′dsc)5]+ +e- → Co(RR′dsc)3+ Co(RR dsc)2. Electrochemical oxidation data obtained at mercury electrodes for the diselenocarbamate complexes are complicated by adsorption but are similar to that found at platinum electrodes. This contrasts with the dithiocarbamates where a mercury electrode specific pathway is observed. Cobalt-59 n.m.r. spectroscopy in dichloromethane shows the non- equivalence of the two cobalt atoms in [Co2(RR′dsc)5]+. The chemical shifts for Co(RR′dsc)3 complexes exhibit similar substituent effects to the dithiocarbamates in cobalt-59 n.m.r. measurements as was the case in oxidative electrochemistry. Cobalt-59 n.m.r. spectroscopy and mass spectrometry demonstrate that exchange, substitution and redox reactions can lead to the formation of mixed ligand diselenocarbamate complexes and mixed dithiocarbamate/diselenocarbamate complexes for both the cobalt(III) monomers and dimers.

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37

Nagababu, Penumaka, J. Naveena Lavanya Latha, P. Pallavi, S. Harish, and S. Satyanarayana. "Studies on antimicrobial activity of cobalt(III) ethylenediamine complexes." Canadian Journal of Microbiology 52, no. 12 (December 1, 2006): 1247–54. http://dx.doi.org/10.1139/w06-087.

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A series of cobalt(III) mixed ligand complexes of type [Co(en)2L]+3, where L is bipyridine, 1,10-phenanthroline, imidazole, methylimidazole, ethyleimidazole, dimethylimidazole, urea, thiourea, acetamide, thioacetamide, semicarbazide, thiosemicarbazide, or pyrazole, have been isolated and characterized. The structural elucidation of these complexes has been explored by using absorption, infrared, and 1H NMR nuclear magnetic resonance spectral methods. The infrared spectral data of all these complexes exhibit a band at 1450/cm and 1560–1590/cm, which correspond to C = C and C = N, a band at 575/cm for Co-N (en), and a band at 480/cm for Co-L (ligand). All these complexes were found to be potent antimicrobial agents. The antibacterial activity was studied in detail in terms of zone inhibition, minimum bactericidal, and time period of lethal action. Among all, complexes bipyridine, 1,10-phenanthroline, dimethylimidazole, and pyrazole, possess the highest antibacterial activity. Antifungal activity was done by disc-diffusion assay and 50% inhibitory concentrations that possess high antifungal activity.Key words: cobalt(III) complexes, ethylenediamine, antimicrobial, antifungal.

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38

Srivastava, Shilpi. "SYNTHESIS, SPECTROSCOPIC, THERMAL AND BIOLOGICAL STUDIES ON MANGANESE(III), IRON(III) AND COBALT(III) COMPLEXES WITH BIS(MERCAPTO AZOLES)." International Journal of Advanced Research 9, no. 11 (November 30, 2021): 351–62. http://dx.doi.org/10.21474/ijar01/13750.

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Complexes of bis(mercapto azoles) i.e. bis(mercapto triazoles), bis(mercapto thiadiazoles) and bis(mercapto oxadiazoles) (LH2) with manganese(III), iron(III) and cobalt(III) have been prepared in methanol in the presence of sodium hydroxide and binuclear products of the type Na[M(L)2(H2O)2] have been isolated. Tentative structural conclusions are drawn for these complexes based upon elemental analyses, electrical conductance, magnetic moment and spectral (electronic, infrared and 1H NMR) data. The thermal stability and mode of decomposition for the complexes have been studied by TG, DTA and DSC techniques. The antifungal, antiviral and antibacterial activities of the ligands and their corresponding complexes were also investigated.

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39

Mulyana, Yanyan, Kerwyn G. Alley, Kristian M. Davies, Brendan F. Abrahams, Boujemaa Moubaraki, Keith S. Murray, and Colette Boskovic. "Dinuclear cobalt(ii) and cobalt(iii) complexes of bis-bidentate napthoquinone ligands." Dalton Trans. 43, no. 6 (2014): 2499–511. http://dx.doi.org/10.1039/c3dt52811a.

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Seven dinuclear cobalt complexes with bridging bis-bidentate naphthoquinone ligands reveal the steric influence of the ancillary capping ligand on the redox potential of the cobalt centres, with metal-catalysed derivatisation of the bridging ligand also observed.

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40

Fang, Jiaxin, Kuldip Singh, and Kogularamanan Suntharalingam. "Anti-Cancer Stem Cell Cobalt(III)-Polypyridyl Complexes Containing Salicylic Acid." Inorganics 12, no. 8 (July 27, 2024): 202. http://dx.doi.org/10.3390/inorganics12080202.

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Metal-containing compounds are an important class of chemotherapeutics used to treat various manifestations of cancer. Despite the widespread clinical use and success of metallopharmaceuticals, they are ineffective towards a sub-population of tumours called cancer stem cells (CSCs). CSCs evade current chemotherapeutic regimens (including metallopharmaceuticals) and promote cancer relapse and metastasis. Here, we report the synthesis, characterisation and anti-breast CSCs properties of a series of cobalt(III)-polypyridyl complexes with salicylic acid. The lead cobalt(III) complex 6 (containing 3,4,7,8-tetramethyl-1,10-phenanthroline) displayed low micromolar potency towards breast CSCs, significantly lower than the gold-standard anti-breast CSC agent, salinomycin, and the clinically used metallodrug, cisplatin. Mechanistic studies indicate that the cobalt(III) complex 6 induces its anti-breast CSC effect by entering breast CSCs, penetrating the nuclei, damaging nuclear DNA and triggering caspase-dependent apoptosis. The cytotoxic mechanism of action of the cobalt(III) complex 6 is also dependent on the modulation of cyclooxygenase-2 (COX-2) expression. This work highlights the anti-breast CSC properties of cobalt(III) coordination complexes with non-steroidal anti-inflammatory drugs (NSAIDs) and more widely spotlights the importance of metallopharmaceuticals in the development of new anticancer agents that can tackle chemotherapeutic-resistant sub-populations.

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41

Mochizuki, Katsura, Seiichiro Higashiya, Masaki Uyama, and Tomoyo Kimura. "Selective syntheses of heterobinuclear cobalt(III)–nickel(II) and cobalt(III)–copper(II) complexes with a bimacrocyclic ligand via‘lariat nickel(II) or cobalt(III) complexes’." J. Chem. Soc., Chem. Commun., no. 23 (1994): 2673–74. http://dx.doi.org/10.1039/c39940002673.

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42

Yamanari, Kazuaki, Makiko Kida, Takashi Fujihara, Akira Fuyuhiro, and Sumio Kaizaki. "Hetero-Ligand Assembly onto Cobalt(III) Complexes." Chemistry Letters 24, no. 8 (August 1995): 673–74. http://dx.doi.org/10.1246/cl.1995.673.

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43

Robinson, K. D., I. F. Burshtein, and A. L. Poznyak. "Chloromercurates of two aminecarboxylate cobalt(III) complexes." Acta Crystallographica Section A Foundations of Crystallography 52, a1 (August 8, 1996): C303. http://dx.doi.org/10.1107/s0108767396087387.

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44

Fourmigué, M., and V. Perrocheau. "Two Heteroleptic Cobalt(III) Cyclopentadienyl/Dithiolene Complexes." Acta Crystallographica Section C Crystal Structure Communications 53, no. 9 (September 15, 1997): 1213–15. http://dx.doi.org/10.1107/s0108270197005544.

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45

Tsubomura, Taro, Shigenobu Yano, and Sadao Yoshikawa. "Cobalt(III) Complexes Containing an Aldonic Acid." Bulletin of the Chemical Society of Japan 61, no. 10 (October 1988): 3497–501. http://dx.doi.org/10.1246/bcsj.61.3497.

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46

Nath, Jayanta Kumar, and Jubaraj B. Baruah. "Azide containing bipyridine complexes of cobalt(III)." Polyhedron 36, no. 1 (April 2012): 1–5. http://dx.doi.org/10.1016/j.poly.2012.01.009.

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47

Bacchi, A., F. Ferranti, and G. Pelizzi. "Structures of two cobalt(III) sepulchrate complexes." Acta Crystallographica Section C Crystal Structure Communications 49, no. 6 (June 15, 1993): 1163–69. http://dx.doi.org/10.1107/s0108270192012265.

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48

Kumar, Challa V., and Jyotsna Thota. "Photocleavage of Lysozyme by Cobalt(III) Complexes." Inorganic Chemistry 44, no. 4 (February 2005): 825–27. http://dx.doi.org/10.1021/ic0488233.

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49

Kostyanovsky, Remir G., Vladimir Yu Torbeev, and Konstantin A. Lyssenko. "Spontaneous resolution of chiral cobalt(III) complexes." Tetrahedron: Asymmetry 12, no. 19 (October 2001): 2721–26. http://dx.doi.org/10.1016/s0957-4166(01)00480-3.

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50

Yasui, Takaji, Tomoharu Ama, and Hiroshi Kawaguchi. "Stereoselective isomerization of chiral cobalt(III) complexes." Polyhedron 13, no. 13 (July 1994): 1963–68. http://dx.doi.org/10.1016/s0277-5387(00)83478-6.

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