Journal articles: 'Metal-arene compounds'

1

Harris, Ronald L. "Bis(arene)metal compounds." Journal of Organometallic Chemistry 299, no. 1 (January 1986): 105–10. http://dx.doi.org/10.1016/0022-328x(86)84037-2.

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Pekachaki, Henrik Margharian, Saeed Taghvaei-Ganjali, Fereshteh Motiee, and Mandana Saber-Tehrani. "APPLICATION OF CALIXARENE DERIVATIVES AS TACKIFIER RESIN IN RUBBER COMPOUNDS FOR TIRE APPLICATIONS." Rubber Chemistry and Technology 92, no. 3 (July 1, 2019): 467–80. http://dx.doi.org/10.5254/rct.19.81510.

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ABSTRACT The effect of p-tert-Butylcalix[4]arene on rubber-nylon-6 fabric and rubber-metal bead wire adhesion strength was quantified. For this purpose, two typically used rubber compounds were employed for two reinforcing motorcycle tire components: ply and bead. The standard pull-out tests of rubber–fabric and rubber–metal showed improvements in adhesion strength by incorporating p-tert-Butylcalix[4]arene into rubber compounds. However, the maximum values of adhesion force to pull the polyamide fabrics and brass-coated metal wires out of the rubber compounds were observed when only 1.0 phr of p-tert-Butylcalix[4]arene was used. The adhesion performance of both fabric and metal wire decreased with higher loading amounts of p-tert-Butylcalix[4]arene. The effect of a commercial phenolic tackifying resin was also evaluated in bead compound. Very similar adhesion results to p-tert-Butylcalix[4]arene were obtained when using 1.0 phr phenolic resin.

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Hansen, Valerie M., Jonathan L. Male, and Roland K. Pomeroy. "Arene–manganese and arene–rhenium compounds of formula (arene)M(CO)2(SiCl3)." Canadian Journal of Chemistry 75, no. 5 (May 1, 1997): 531–35. http://dx.doi.org/10.1139/v97-062.

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Derivatives of formula (arene)M(CO)2(SiCl3) (M = Mn, Re) have been prepared in moderate to good yield by the reaction of M(CO)5(SiCl3) and the appropriate arene (with heptane in those cases where the arene was a solid) in an evacuated sealed tube at 230–260 °C for 12–24 h, depending on the arene and the metal. Carefully purified reagents were necessary to obtain satisfactory yields. The (η6-1,4-C6H4tBu2)M(CO)2(SiCl3) complexes in solution exhibit free rotation of the arene ring about the metal atom to −120 °C as ascertained by 1H NMR spectroscopy. The manganese compound did show the onset of decoalescence of two of the signals due to the arene ligand in the 13C{1H} NMR spectrum in CD2Cl2, solution below −90 °C. This, however, is interpreted in terms of restricted rotation of the tert-butyl substituent rather than restricted rotation of the arene ring. Keywords: arene, manganese, rhenium, restricted rotation.

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Wang, Jie, Hongyu Guan, Chunhua Ge, Ping Fan, Xijuan Xing, and Yunshan Shang. "Azocalix[4]arene with three distal ethyl ester residues as a highly selective chromogenic sensor for Ca2+ ions." Heterocyclic Communications 24, no. 3 (June 27, 2018): 147–50. http://dx.doi.org/10.1515/hc-2017-0239.

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AbstractThree azocalix[4]arenes with distal ethyl ester residues, 5-phenylazo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (2), 5-(o-methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (3), 5-(p-Methylphenyl)azo-25,26,27-tris[(ethoxycarbonyl)methoxy]-28-hydroxycalix[4]arene (4), were synthesized and their binding properties with metal ions were investigated by ultraviolet (UV)/visible spectroscopy. The chromogenic behavior of these compounds upon metal ion complexation indicates a specific selectivity toward Ca2+ ion in the presence of other cations tested. The stoichiometry of 3 to Ca2+ ion in the complex is 1:1 and the stability constant of the complex is 1.28×104m−1.

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Zhi, Sanjun, Hongjun Yao, and Wei Zhang. "Difunctionalization of Dienes, Enynes and Related Compounds via Sequential Radical Addition and Cyclization Reactions." Molecules 28, no. 3 (January 23, 2023): 1145. http://dx.doi.org/10.3390/molecules28031145.

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Radical reactions are powerful in creating carbon–carbon and carbon–heteroatom bonds. Designing one-pot radical reactions with cascade transformations to assemble the cyclic skeletons with two new functional groups is both synthetically and operationally efficient. Summarized in this paper is the recent development of reactions involving radical addition and cyclization of dienes, diynes, enynes, as well as arene-bridged and arene-terminated compounds for the preparation of difunctionalization cyclic compounds. Reactions carried out with radical initiators, transition metal-catalysis, photoredox, and electrochemical conditions are included.

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Schneider, Jörg J., and Dirk Wolf. "Mechanistische Untersuchungen zum reversiblen Gleichgewicht von metallorganischen Tripeldecker- und Sandwichkomplexen des Typs [Bis{(η5-CpR)Co}-μ-{η4:η4-aren}] und [(η5-CpR)Co(η6-aren)] / Mechanistic Studies towards the Reversible Equilibrium between Metal Organic Triple Decker and Sandwich Complexes [Bis{(η5 -CpR)Co}-μ-{η4 :η4-arene}] and [{(η5-CpR)Co(η6-arene)]." Zeitschrift für Naturforschung B 53, no. 11 (November 1, 1998): 1267–72. http://dx.doi.org/10.1515/znb-1998-1105.

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The arene ligand exchange mechanism of slipped arene triple deckers [Bis{(η5-CpR)Co}-μ-{η4:η4-arene}] (R = Me5, 1,2,4 tri-tert butyl, arene = benzene, toluene) 1 was studied by 1H-NMR spectroscopy for different concentrations and solvents. It has been found that triple deckers of type 1 decompose slowly in solution. A unique equilibrium, between these triple deckers and the mixed sandwich complexes [(η6-arene)Co(η5-CpR)] and 14 e [(η5-Cp)Co]solv fragments generated in situ by decomposition o f 1 exists. In addition to this equilibrium arene lability of the thus formed mixed sandwich complex type has been detected by NMR making slipped triple deckers 1 ideal single source compounds for the generation of two [(η5-Cp)Co] fragments in one reaction step. Such fragments are valuable metal ligand components with high synthetic utility in organometallic chemistry.

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7

Küppers, Luca, and Walter Frank. "Investigation of mesitylene-solvated group 13 mixed-metal halides: syntheses and crystal structures of bis(1,3,5-trimethylbenzene)gallium(I) tetrachlorido- and tetrabromidoaluminate(III) and (1,3,5-trimethylbenzene)gallium(I) tetraiodidoaluminate(III). Variation of the gallium-π-arene bond strength." Zeitschrift für Naturforschung B 74, no. 10 (October 25, 2019): 773–82. http://dx.doi.org/10.1515/znb-2019-0139.

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AbstractBis(1,3,5-trimethylbenzene)gallium(I) tetrachloridoaluminate(III), [(1,3,5-(CH3)3C6H3)2Ga][AlCl4] (1), bis(1,3,5-trimethylbenzene)gallium(I) tetrabromidoaluminate(III), [(1,3,5-(CH3)3C6H3)2Ga][AlBr4] (2) and (1,3,5-trimethylbenzene)gallium(I) tetraiodidoaluminate(III), [1,3,5-(CH3)3C6H3Ga][AlI4] (3) were synthesized from the corresponding subvalent GaI/AlIII mixed metal halides and characterized via C,H analysis, Raman spectroscopy, X-ray powder diffraction and X-ray single crystal diffraction. Compound 1 crystallizes in the noncentrosymmetric monoclinic space group Cc isotypic to [(1,3,5-(CH3)3C6H3)2Ga][GaCl4]. For 2 and 3 the monoclinic space group P21/n is found, however, they are neither isotypic nor homotypic. While 2 is isotypic to [(1,3,5-(CH3)3C6H3)2In][InBr4], 3 establishes a new structure type. In the solids of all three title compounds coordination polymeric chains are found, in 1 and 2 built up from bis(arene)-coordinated, in 3 from mono(arene)-coordinated Ga+ ions and the corresponding AlX4− anions in a 1κCl:2κCl′ (1), 1κCl,Cl′:2κCl″ (2) or 1κCl,Cl′:2κCl″:3κCl‴ (3) bridging mode. Taking into account the weaker coordinating character of the AlCl4− as compared to the AlBr4− anion, in line with expectations the number of gallium halogen contacts is increased and the strength of the π-arene bonding is reduced in the bromide 2 as compared to the chloride 1. Finally, with the even more strongly coordinating AlI4− anion the arene coordination is limited to one molecule. Considering mesitylene complexes of gallium, the formation of a mono(arene) complex is unprecedented and even considering group 13 elements in general, the formation of a mono(mesitylene) complex like 3 is unusual. Furthermore, compound 3 is the first structurally characterized arene solvate of a main group metal tetraiodidometallate.

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8

Preda, Ana-Maria, Małgorzata Krasowska, Lydia Wrobel, Philipp Kitschke, Phil C. Andrews, Jonathan G. MacLellan, Lutz Mertens, et al. "Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study." Beilstein Journal of Organic Chemistry 14 (August 15, 2018): 2125–45. http://dx.doi.org/10.3762/bjoc.14.187.

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The dispersion type Bi···π arene interaction is one of the important structural features in the assembly process of arylbismuth compounds. Several triarylbismuth compounds and polymorphs are discussed and compared based on the analysis of single crystal X-ray diffraction data and computational studies. First, the crystal structures of polymorphs of Ph3Bi (1) are described emphasizing on the description of London dispersion type bismuth···π arene interactions and other van der Waals interactions in the solid state and the effect of it on polymorphism. For comparison we have chosen the substituted arylbismuth compounds (C6H4-CH═CH2-4)3Bi (2), (C6H4-OMe-4)3Bi (3), (C6H3-t-Bu2-3,5)3Bi (4) and (C6H3-t-Bu2-3,5)2BiCl (5). The structural analyses revealed that only two of them show London dispersion type bismuth···π arene interactions. One of them is the styryl derivative 2, for which two polymorphs were isolated. Polymorph 2a crystallizes in the orthorhombic space group P212121, while polymorph 2b exhibits the monoclinic space group P21/c. The general structure of 2a is similar to the monoclinic C2/c modification of Ph3Bi (1a), which leads to the formation of zig-zag Bi–arenecentroid ribbons formed as a result of bismuth···π arene interactions and π···π intermolecular contacts. In the crystal structures of the polymorph 2b as well as for 4 bismuth···π arene interactions are not observed, but both compounds revealed C–HPh···π intermolecular contacts, as likewise observed in all of the three described polymorphs of Ph3Bi. For compound 3 intermolecular contacts as a result of coordination of the methoxy group to neighboring bismuth atoms are observed overruling Bi···π arene contacts. Compound 5 shows a combination of donor acceptor Bi···Cl and Bi···π arene interactions, resulting in an intermolecular pincer-type coordination at the bismuth atom. A detailed analysis of three polymorphs of Ph3Bi (1), which were chosen as model systems, at the DFT-D level of theory supported by DLPNO-CCSD(T) calculations reveals how van der Waals interactions between different structural features balance in order to stabilize molecular arrangements present in the crystal structure. Furthermore, the computational results allow to group this class of compounds into the range of heavy main group element compounds which have been characterized as dispersion energy donors in previous work.

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9

Hanif, Muhammad, Patricia Schaaf, Wolfgang Kandioller, Michaela Hejl, Michael A. Jakupec, Alexander Roller, Bernhard K. Keppler, and Christian G. Hartinger. "Influence of the Arene Ligand and the Leaving Group on the Anticancer Activity of (Thio)maltol Ruthenium(II)–(η6-Arene) Complexes." Australian Journal of Chemistry 63, no. 11 (2010): 1521. http://dx.doi.org/10.1071/ch10232.

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Maltol and its metal complexes have shown promising applications in medicinal chemistry. We report here the synthesis and characterization of Ru(η6-arene)(halido) coordination compounds bearing maltol or thiomaltol ligands and studies on their behaviour in aqueous solution, their reactions with the DNA model guanosine 5′-monophosphate (5′-GMP) and their in vitro anticancer activity in human tumour cell lines. The compounds hydrolyze rapidly and quantitatively to the respective aqua species by exchange of the halido ligand. With pKa values of >8, such species would also be present in biological media and they proved reactive to 5′-GMP. The thiomaltol compounds show promising in vitro activity with IC50 values (50% inhibitory concentration) in the low micromolar range, whereas activity of the maltol complexes is marginal. Variation of the arene ligand (benzene, toluene, p-cymene or biphenyl) resulted only in minor changes in activity.

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10

Profilet, Robert D., Arlene P. Rothwell, and Ian P. Rothwell. "Surface-supported group 5 metal organometallic compounds for catalytic arene hydrogenation." Journal of the Chemical Society, Chemical Communications, no. 1 (1993): 42. http://dx.doi.org/10.1039/c39930000042.

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11

Kniazeva, Mariia V., Alexander S. Ovsyannikov, Daut R. Islamov, Aida I. Samigullina, Aidar T. Gubaidullin, Svetlana E. Solovieva, Igor S. Antipin, and Sylvie Ferlay. "Formation of Unsymmetrical Trinuclear Metallamacrocycles Based on Two Different Cone Calix[4]arene Macrocyclic Rings." Crystals 10, no. 5 (May 1, 2020): 364. http://dx.doi.org/10.3390/cryst10050364.

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A combination of tetrasulfonylcalix[4]arene (3-4H) together with a calix[4]arene dicarboxylate derivative 2-4H led, in the presence of MII(NO3)2 (M = Co, Ni, Zn), to the formation of three novel isostructural metallomacrocycles of formula [M3(DMF)2(μ3-H2O)-(2-2H)-3]. The structure of the prepared coordination compounds was studied in the solid state using single crystal/powder X-ray diffraction studies. The X-ray diffraction on single crystal revealed that the structure of the obtained supramolecular complexes is composed of a trinuclear metallic cluster [M3]+6 held between one di-deprotonated molecule of (2-2H)2− offering two carboxylate groups for binding metal cations and one tetra-deprotonated compound 34−, where four oxygen atoms, belonging to four deprotonated phenolic moieties and three oxygen atoms coming from three SO2 groups, are coordinated with the cluster core. Thus, an example of an easily reproducible molecular recognition pattern involving two different types of calix[4]arene based ligands, displaying different coordination moieties, and trinuclear metallic clusters, is reported here. In addition, it has been shown that the cone moieties of the calixarene also encapsulate solvent molecules.

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12

Ohto, Keisuke, Nako Fuchiwaki, Hiroaki Furugou, Shintaro Morisada, Hidetaka Kawakita, Marco Wenzel, and Jan J. Weigand. "Comparative Extraction of Aluminum Group Metals Using Acetic Acid Derivatives with Three Different-Sized Frameworks for Coordination." Separations 8, no. 11 (November 8, 2021): 211. http://dx.doi.org/10.3390/separations8110211.

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We prepared acetic acid derivatives using three different frameworks, calix[4]arene, alkenyltrimethylol, and trihydroxytriphenylmethane, which differ in the number and size of their coordination sites. We further investigated the extraction properties for aluminum group metal ions. All three extraction reagents exhibited increased extraction compared with the corresponding monomeric compounds, owing to structural effects. The extraction reaction and extraction equilibrium constants were determined using a slope analysis. Their extraction abilities, separation efficiencies, and potential coordination modes are discussed using the extraction equilibrium constants, half-pH values, and spectroscopic data. The calix[4]arene and trihydroxytriphenylmethane derivatives demonstrated allosteric co-extraction of indium ions (In3+) with an unexpected stoichiometry of 1:2.

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13

Bush, Benjamin F., Vincent M. Lynch, and J. J. Lagowski. "Transition-metal organometallic compounds. 8. Arene exchange reactions of bis(naphthalene)chromium." Organometallics 6, no. 6 (June 1987): 1267–75. http://dx.doi.org/10.1021/om00149a024.

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14

Casagrande, Jr., Osvaldo L., Elton L. S. Gomes, Jairton Dupont, Robert Burrow, and Alan J. Lough. "Heterometallic metal carbonyl compounds derived from (η6-arene)tricarbonylchromium bearing propargyl units." Journal of the Chemical Society, Dalton Transactions, no. 10 (2001): 1634–38. http://dx.doi.org/10.1039/b009591p.

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15

Schwamm, Ryan J., Christopher M. Fitchett, and Martyn P. Coles. "Intramolecular Metal⋅⋅⋅π‐Arene Interactions in Neutral and Cationic Main Group Compounds." Chemistry – An Asian Journal 14, no. 8 (January 16, 2019): 1204–11. http://dx.doi.org/10.1002/asia.201801729.

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16

Bahojb Noruzi, Ehsan, Behrouz Shaabani, Silvano Geremia, Neal Hickey, Patrizia Nitti, and Hossein Samadi Kafil. "Synthesis, Crystal Structure, and Biological Activity of a Multidentate Calix[4]arene Ligand Doubly Functionalized by 2-Hydroxybenzeledene-Thiosemicarbazone." Molecules 25, no. 2 (January 16, 2020): 370. http://dx.doi.org/10.3390/molecules25020370.

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The design and synthesis of a novel tert-butyl-calix[4]arene functionalized at 1, 3 positions of the lower rim with two terminal 2-hydroxybenzeledene-thiosemicarbazone moieties is reported. The new ligand with multi-dentate chelating properties was fully characterized by several techniques: ESI-Mass spectroscopy, FT-IR, 1H-NMR, and single crystal X-ray diffraction. The solid state structure confirms that the calix[4]arene macrocycle has the expected open cone conformation, with two opposite phenyl rings inclined outwards with large angles. The conformation of the two alkoxythiosemicarbazone arms produces a molecule with a C2 point group symmetry. An interesting chiral helicity is observed, with the two thiosemicarbazone groups oriented in opposite directions like a two-blade propeller. A water molecule is encapsulated in the center of the two-blade propeller through multiple H-bond coordinations. The antibacterial, antifungal, anticancer, and cytotoxic activities of the calix[4]arene-thiosemicarbazone ligand and its metal derivatives (Co2+, Ni2+, Cu2+, and Zn2+) were investigated. A considerable antibacterial activity (in particular against E. coli, MIC, and MBC = 31.25 μg/mL) was observed for the ligand and its metal derivatives. Significant antifungal activities against yeast (C. albicans) were also observed for the ligand (MIC = 31.25 μg/mL and MBC = 125 μg/mL) and for its Co2+ derivative (MIC = 62.5 μg/mL). All compounds show cytotoxicity against the tested cancerous cells. For the Saos-2 cell line, the promising anticancer activity of ligand L (IC50 < 25 μg/mL) is higher than its metal derivatives. The microscopic analysis of DAPI-stained cells shows that the treated cells change in morphology, with deformation and fragmentation of the nuclei. The hemo-compatibility study demonstrated that this class of compounds are suitable candidates for further in vivo investigations.

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17

Tabaza, Taha A., Omar T. Tabaza, and Amjad Al-Sakarneh. "CVD Technology for Preparing Chromium Oxide Coatings, Study of the Kinetics of Growth of Coatings." Key Engineering Materials 765 (March 2018): 193–98. http://dx.doi.org/10.4028/www.scientific.net/kem.765.193.

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Metal coating nowadays is very essential in heavy industry and many other applications, however, a coating system is designed and built to obtain pyrolytic Chrome-Oxide Cr2O3, so oxygen is distributed through the coating in order to enhance its properties depending on metal-organic compounds (MOC). A very large number of experiments have been performed to study the effect of oxidant comparing with inert atmosphere. A chemical vapor deposition method for preparing chromium oxide Cr2O3 coatings from bis-arene chromium compounds has been performed, followed by studying the effect of oxidant substances concentration on the kinetics of growth of coatings. The main finding is that coatings exhibit excellent adhesion, high microhardness, and wear resistance. The coating process is characterized by high adaptability and relatively low cost.

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18

PROFILET, R. D., A. P. ROTHWELL, and I. P. ROTHWELL. "ChemInform Abstract: Surface-Supported Group 5 Metal Organometallic Compounds for Catalytic Arene Hydrogenation." ChemInform 24, no. 17 (August 20, 2010): no. http://dx.doi.org/10.1002/chin.199317093.

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19

Harvey, Pierre D., Jonathan Gagnon, Réjean Provencher, Bing Xu, and Timothy M. Swager. "Tungsten and molybdenum oxo complexes of tetrakis(phenyldiazenyl)calix[4]arene substituted derivatives: EHMO calculations, spectroscopic characterization, and perturbations of the photophysical properties by neutral guest molecules." Canadian Journal of Chemistry 74, no. 11 (November 1, 1996): 2279–88. http://dx.doi.org/10.1139/v96-256.

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Bowl-shaped chromophores fabricated with tungsten and molybdenum oxo complexes of calix[4]arenes substituted at the para positions with phenyldiazenyl (R2C6H3N2) derivatives are investigated. The nature of the lowest energy excited states has been addressed theoretically using Extended Hückel Molecular Orbital (EHMO) calculations and experimentally using UV-visible, luminescence, and polarized emission spectroscopy at 77 K. The lowest energy excited states are intraligand (azobenzene fragment) ππ* (S2 and T2) and ππ*states (S1, and T1). The compounds are weakly luminescent in the 600–630 nm range exhibiting emissions arising from the 1(ππ*) states [Formula: see text]. The region located above 900 nm was not investigated. Evidence for guest–host chemistry has been demonstrated by1H-NMR spectroscopy, and the binding constants for two of the compounds with pyridine in toluene as a solvent were obtained by UV–visible spectroscopy. The presence of a guest molecule inside the luminescent metal oxo complex of a calix[4]arene hosts decreases the emission lifetimes.Key words: host–guest, photophysics, calix[4]arene, EHMO, fluorescence

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20

Mokhtari, Bahram, and Kobra Pourabdollah. "Extraction of s-block metals by nano-baskets of calix[4]crown-3." Canadian Journal of Chemistry 90, no. 6 (June 2012): 560–66. http://dx.doi.org/10.1139/v2012-020.

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Three kinds of nano-baskets including 1,2-alternate and cone conformers of di-ionizable p-tert-butylcalix[4]arene-1,2-crown-3 and the cone conformer of p-tert-butylcalix[4]arene-1,2-thiacrown-3 were synthesized and the competitive solvent extractions of alkali and alkaline earth metal cations were studied. The novelty of this study is including three binding units of the calixarene’s bowl, the crown ether’s ring, and electron-donor ionizable moieties in a unique scaffold, in which their sizes were selected based upon their complexation ability to show equal binding tendency towards the cations. The objective of this work is to assess the extraction efficiency, selectivity, and pH1/2 of such complexes. The results of solvent extraction experiments indicated that these compounds were effective extractants of alkali and alkaline earth metal cations. Their selectivities were greatly influenced by the acidity of the solution and the conformations of the calixcrown. One conformer was highly selective to Na+ and the other to Ba2+ in acidic and basic solutions, respectively.

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Saloutin, Victor I., Yulia S. Kudyakova, Marina V. Goryaeva, Yanina V. Burgart, and Oleg N. Chupakhin. "Polyfluoroalkylated 2-ethoxymethylene- 3-oxo esters: synthesis and chemical properties overview." Pure and Applied Chemistry 89, no. 8 (July 26, 2017): 1209–22. http://dx.doi.org/10.1515/pac-2016-1015.

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AbstractThe review focuses on the synthesis and chemical properties of polyfluoroalkylated 2-ethoxymethylene-3-oxo esters. The scope and peculiarities of their use as organic reagents in reactions with various N-, C-, O-, mono- and dinucleophiles are discussed in detail. The high reactivity of such derivatives is employed in the construction of enaminoketone, arene and heterocycle frameworks. Particular attention is paid to applications of these building blocks as chemicals for fine organic synthesis, bioactive compounds and metal complexes synthesis.

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Shahnavaz, Zohreh, Lia Zaharani, Mohd Rafie Johan, and Nader Ghaffari Khaligh. "A Green Alternative for Aryl Iodide Preparation from Aromatic Amines." Current Organic Synthesis 17, no. 2 (May 8, 2020): 131–35. http://dx.doi.org/10.2174/1570179417666200203121437.

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Background: In continuation of our previous work and the applications of saccharin, we encouraged to investigate the one-pot synthesis of the aryl iodides by the diazotization of the arene diazonium saccharin salts. Objective: Arene diazonium salts play an important role in organic synthesis as intermediate and a wide variety of aromatic compounds have been prepared using them. A serious drawback of arene diazonium salts is their instability in a dry state; therefore, they must be stored and handled carefully to avoid spontaneous explosion and other hazard events. Methods: The arene diazonium saccharin salts were prepared as active intermediates in situ through the reaction of various aryl amines with tert-butyl nitrite (TBN) in the presence of saccharin (Sac–H). Then, in situ obtained intermediates were used into the diazotization step without separation and purification in the current protocol. Results: A variety of aryl iodides were synthesized at a greener and low-cost method in the presence of TBN, Sac–H, glacial acetic acid, and TEAI. Conclusion: In summary, a telescopic reaction is developed for the synthesis of aryl iodides. The current methodology is safe, cost-effective, broad substrate scope, and metal-free. All used reagents are commercially available and inert to moisture and air. Also, the saccharine and tetraethylammonium cation could be partially recovered from the reaction residue, which reduces waste generation, energy consumption, raw material, and waste disposal costs.

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23

Ferguson, George, Alan J. Lough, Anna Notti, Sebastiano Pappalardo, Melchiorre F. Parisi, and Giuseppe Resnati. "Synthesis and ESI-MS Alkali Metal Ion Binding Selectivities of Cone, Partial Cone, and 1,3-Alternate 1,3-Bis(α-picolyloxy)-p-tert-butylcalix[4]arene Crown-6 and 1,1'-Binaphthalene-2,2'-diyl Crown-6 Conformers." Collection of Czechoslovak Chemical Communications 69, no. 5 (2004): 1109–25. http://dx.doi.org/10.1135/cccc20041109.

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The syntheses of 1,3-bis(α-picolyloxy)-p-tert-butylcalix[4]arene crown-6 and 1,1'-binaphthalene-2,2'-diyl crown-6 title conformers have been achieved by two complementary synthetic strategies, which differ in the order in which the polyether loop and the pendant picolyl groups are introduced. The structure and conformation of all new compounds have been firmly established by NMR spectroscopy, and further proven by X-ray analysis for the intermediate p-tert-butyl-25,27-(1,1'-binaphthalene-2,2'-diyl-crown-6)-26,28-dihydroxycalix[4]arene. Within each set of conformers, the nature of the polyether chain has little or no influence on the overall conformation of the calixarene platform. The alkali metal ion binding selectivities of the two series of calixarenes have been evaluated in competitive complexation experiments by electrospray ionization mass spectrometry. In the p-tert-butylcalix[4]arene crown-6 series, partial cone and 1,3-alternate conformers show a peak selectivity for the larger Cs+ ions, while the cone one preferentially binds the smaller Na+ ions. On the other hand, the cone and 1,3-alternate binaphthyl-containing analogues show a preference for Na+ ions, the partial cone being quite unselective.

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24

Martins, Felipe Terra, Angélica Faleiros da Silva Maia, Fernando Machado dos Santos, Meiry Edivirges Alvarenga, Leandro Ribeiro, Leonardo da Silva Neto, and Ângelo de Fátima. "Guest-driven unusual conformations in two calix[6]arene solvates and a new calix[8]arene." Zeitschrift für Kristallographie - Crystalline Materials 233, no. 8 (July 26, 2018): 565–78. http://dx.doi.org/10.1515/zkri-2017-2110.

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Abstract Unusual conformations have been found in a new calix[8]arene and in new solvates of two known calix[6]arenes. The chair-like conformation with 2/m point group symmetry was found for the first time in the dimethylformamide (DMF) disolvate of the basic calix[6]arene (1) without substituents in the lower and upper rims. Such symmetry is driven by the guest geometry allowing for two equivalent hydrogen bonding patterns in the chair seat. This avoids cone distortion found in the other chair-like conformers, although they have energies lower than that of new symmetrical conformer. The molecular conformation of hexa(carboxymethoxy)calix[6]arene (2) is also described as a dimethylsulfoxide (DMSO) pentasolvate. Its conformation can be described as a 1,3,5-closed cone with three alternate phenyl rings inclined inwards to the cone, thereby closing the cone entrance. Such a conformation also suggests five acid groups are pointed towards the same side of the calyx base and are able to bind metal ions or basic compounds in the lower rim, while inclusion of guests into the cone cavity is hindered. Both inclusion and cooperative acid binding/coordination abilities are still more hindered in the lowest energy 1,2,3-alternate cone conformer of 2. The role of the solvent in avoiding cone distortion was highlighted by inspecting the conformations of 5,11,17,23,29,35,41,47-octanitro-49,50,51,52,53,54,55,56-octa-n-butoxycalix[8]arene (3) and the known nitro analogues having methyl instead of n-butyl groups. Cone distortion is found in the non-solvated crystal form of 3, while non-classical hydrogen bonds with tetrahydrofuran preclude this in the literature analogue.

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Tu, Chuqiao, Kazimierz Surowiec, and Richard A. Bartsch. "Efficient divalent metal cation extractions with di-ionizable calix[4]arene-1,2-crown-4 compounds." Tetrahedron 63, no. 19 (May 2007): 4184–89. http://dx.doi.org/10.1016/j.tet.2007.02.105.

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Surowiec, Malgorzata, Radu Custelcean, Kazimierz Surowiec, and Richard A. Bartsch. "Alkali metal cation complexation by 1,3-alternate, mono-ionisable calix[4]arene-benzocrown-6 compounds." Supramolecular Chemistry 27, no. 1-2 (April 23, 2014): 59–64. http://dx.doi.org/10.1080/10610278.2014.904869.

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Oktavia, Rizka, and Sumardi Sumardi. "Kemampuan Bacillus sp. Sebagai Bioremediasi Bahan Pencemar." Jurnal Bioterdidik: Wahana Ekspresi Ilmiah 10, no. 2 (September 30, 2022): 110–25. http://dx.doi.org/10.23960/jbt.v10i2.23919.

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The presence of heavy metal sources in inappropriate places can contaminate the surrounding soil, so that it will interfere with human and animal health if they enter the food chain. The purpose of writing this review is to determine the ability of Bacillus in bioremediation of pollutants and to determine the enzymes in Bacillus that are able to remediate pollutants. Monooxygenase enzymes and dioxygenase enzymes produced by bacteria can open carbon bonds in aromatic rings and produce primary alcohols. Dioxygenase enzymes produced by bacteria reduce PAHs and form cis-dihydrodiol. This compound is then dehydrogenated to form dihydroxy-PAH which is a substrate for the ring-opening enzyme. Through the addition of one oxygen molecule, the monooxygenase enzyme can also reduce PAH and form arene oxide, then these molecules will be used by bacteria as a source of nutrition. Bacillus bacteria are able to remediate various kinds of pollutants. These bacteria are able to reduce these pollutants because they have hydrocarbon enzymes that will break down harmful chemical compounds in pollutants into simpler compounds that can be used as energy sources.

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Weber, Jaques, E. Peter Kundig, Annick Goursot, and Edouard Penigault. "The electronic structures of bis(η6-benzene)- and bis(η6-naphthalene)chromium(0)." Canadian Journal of Chemistry 63, no. 7 (July 1, 1985): 1734–40. http://dx.doi.org/10.1139/v85-291.

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SCF MS Xα molecular orbital calculations are reported for the bis(η6-benzene)- and bis(η6-naphthalene)chromium(0) complexes. The bonding may be essentially discussed in terms of the covalent interactions between the metal 3d and ligand π and π* orbitals. The different charges on chromium atom in the two systems are explained by the different balances between ligand-to-metal (bonding) and metal-to-ligand (back-bonding) electron donations. Some resemblances are found between the electronic structures of the two compounds and it is possible to correlate to a large extent the energy levels of their molecular orbitals. However, a shift towards lower values is predicted for the energy levels of the naphthalene complex, together with a large disruption of all the virtual π* and 3d* levels. This would undoubtedly favor nucleophilic attack followed by metal–ring or carbon–carbon bond cleavage, in agreement with the extreme lability of the coordinated arene rings observed in this complex.

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Elsegood, Mark, Lynne Horsburgh, Carl Redshaw, Oliver Rowe, and Simon Teat. "Pillared 2-D MOFs Based on a Lower-Rim Acid-Appended Calix[4]arene." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C1226. http://dx.doi.org/10.1107/s2053273314087737.

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Calixarenes have been the focus of intense research study of both their organic and metal-coordinated chemistry over the past twenty or so years. Calixarenes generally have intrinsic cavities in their cone or partial cone structures, often filled with coordinated or non-coordinated solvent of crystallization, or filled with substituents from neighboring calixarene molecules. Much of this research has generated molecular, or zero-dimensional compounds, rather than oligomeric or polymeric materials. The shape and size of the calixarene molecules and complexes has led to their use in separation science, catalysis, imaging, etc. Over the same time period, studies on metal-organic frameworks (MOFs) have also been prominent, driven mainly by the ambition to store gases like hydrogen or trap CO2. Metal ions form nodes and bond to organic spacers which generate a rigid or flexible poly-dimensional framework with pores. This research contribution marries the two fields and incorporates calixarene molecules, with their inherent pores, into MOFs. Solvothermal reactions of the lower-rim functionalized diacid calix[4]arene 25,27-bis(methoxycarboxylic acid)-26,28-dihydroxy-4-tert-butylcalix[4]arene (LH2) with Zn(NO3)2·6H2O and the dipyridyl ligands 4,4′-bipyridyl (4,4′-bipy), 1,2-di(4-pyridyl)ethylene (DPE) or 4,4′-azopyridyl (4,4′-azopy) afforded a series of 2-D structures of the formulae {[Zn(4,4′-bipy)(L)]·2¼DEF}n (1, Fig. 1.), {[Zn2(L)(DPE)]·DEF}n (2) and {[Zn(OH2)2(L)(4,4′-azopy)]·DEF}n (3) (DEF = diethylformamide)1. Figure 1. {[Zn(4,4′-bipy)(L)]·2¼DEF}n (1)

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Motswainyana, William M., and Peter A. Ajibade. "Anticancer Activities of Mononuclear Ruthenium(II) Coordination Complexes." Advances in Chemistry 2015 (February 19, 2015): 1–21. http://dx.doi.org/10.1155/2015/859730.

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Ruthenium compounds are highly regarded as potential drug candidates. The compounds offer the potential of reduced toxicity and can be tolerated in vivo. The various oxidation states, different mechanism of action, and the ligand substitution kinetics of ruthenium compounds give them advantages over platinum-based complexes, thereby making them suitable for use in biological applications. Several studies have focused attention on the interaction between active ruthenium complexes and their possible biological targets. In this paper, we review several ruthenium compounds which reportedly possess promising cytotoxic profiles: from the discovery of highly active compounds imidazolium [trans-tetrachloro(dmso)(imidazole)ruthenate(III)] (NAMI-A), indazolium [trans-tetrachlorobis(1H-indazole)ruthenate(III)](KP1019), and sodium trans-[tetrachloridobis(1H-indazole)ruthenate(III)] (NKP-1339) to the recent work based on both inorganic and organometallic ruthenium(II) compounds. Half-sandwich organometallic ruthenium complexes offer the opportunity of derivatization at the arene moiety, while the three remaining coordination sites on the metal centre can be functionalised with various coordination groups of various monoligands. It is clear from the review that these mononuclear ruthenium(II) compounds represent a strongly emerging field of research that will soon culminate into several ruthenium based antitumor agents.

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Sahnoun, Riadh, and Claude Mijoule. "Density Functional Study of Metal−Arene Compounds: Mono(benzene)chromium, Bis(benzene)chromium and Their Cations." Journal of Physical Chemistry A 105, no. 25 (June 2001): 6176–81. http://dx.doi.org/10.1021/jp0034271.

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Ward, James P., Jonathan M. White, and Charles G. Young. "Synthesis, characterization and metal ion complexation and extraction capabilities of calix[4]arene Schiff base compounds." Tetrahedron 69, no. 41 (October 2013): 8824–30. http://dx.doi.org/10.1016/j.tet.2013.05.120.

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Ciardelli, Francesco, and Paolo Pertici. "Structure and Reactivity of Aromatic Polymers/Ruthenium Catalysts." Zeitschrift für Naturforschung B 40, no. 2 (February 1, 1985): 133–40. http://dx.doi.org/10.1515/znb-1985-0201.

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Previously prepared (J. Mol. Catalysis 11, 353 (1981)) polystyrene/ruthenium systems have been examined by EXAFS, TEM, IR and Raman spectroscopy. A structure based on small metal clusters bound to the polymer by single ruthenium-arene binding is proposed. The general validity of the approach has been confirmed by preparing a similar product when starting with poly-1- vinylnaphthalene in the place of polystyrene.Both systems are active for the hydrogenation of a large variety of unsaturated groups such as olefinic double bonds, mononuclear aromatic hydrocarbons, ketones, nitriles, nitroaromatic compounds and oximes. Catalytic activity, chemio- and stereoselectivity are discussed in terms of the proposed structure.

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Cay, Seydahmet, Serkan Sayin, and Mehmet Soner Engin. "Calix[4]arene Embedded Polyamide Supported Liquid Membrane for Separation of Heavy Metals from Aqueous Solutions." Turkish Journal of Agriculture - Food Science and Technology 8, no. 2 (February 27, 2020): 387. http://dx.doi.org/10.24925/turjaf.v8i2.387-391.3064.

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In this study, we aimed to prepare new calixaren embedded mercapto groups supported liquid membranes and to use them in the transport of heavy metals. For this purpose 5,11,17,23-tetra-tert-butyl-25,27-bis(3-thiol-1-oxypropane)-26,28-dihydroxylcalix[4]arene was synthesized. The synthesized calixarene compounds were fully characterized by spectroscopic and the other techniques. The prepared compounds were supported polyamide liquid membranes and obtained calix[4]aren embedded supported liquid membranes (C@PSMs). The characterization of C@PSM was carried out by FTIR, TGA and elemental analysis techniques. Transport experiments were carried out with Pb(II), Cd(II) and Zn(II) as trace metals, to transport from donor phase to accept phase. From the results, it was calculated flux (J) and recovery (RF) values. The affinity (the percentage of metal ion transferred from the source solution) of a PIM towards a range of divalent cations was found to follow the order Zn(II)> Cd(II)> Pb(II).

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Yang, Fafu, Yanhua Wang, Hongyu Guo, Jianwei Xie, and Zhiqiang Liu. "Novel lariat calix[4]-1,3-aza-crowns with two branched chains — The excellent phase transfer catalysts for nucleophilic substitution reaction." Canadian Journal of Chemistry 88, no. 7 (July 2010): 622–27. http://dx.doi.org/10.1139/v10-061.

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By reacting calix[4]-1,3-diethoxylaminoethyl derivative (2) with phenyl isothiocyanate, novel dendritic calix[4]arene derivative (3) with two different branched chains was synthesized in a yield of 78%. By reacting compound 2 with 1,6-diisocyanatohexane or N,N′-bis(2-chloracetamide)ethylene in a “1 + 1” intermolecular addition mode, novel lariat calix[4]-1,3-aza-crowns (4 and 5, respectively) with two branched ethoxyl chains were prepared in reasonable yields. The composition, structures, and conformations of all new compounds were confirmed by elemental analyses, IR, ESI-MS, 1H NMR, and so forth. The liquid–liquid extraction experiments showed that all new hosts possessed good extraction abilities towards soft and hard metal cations. The liquid membrane transport experiments suggested that they had good transport abilities for K+ and Ag+. The experiments of phase transfer catalysis indicated that they possessed excellent catalytic properties of aromatic nucleophilic substitution reaction and benzyl nucleophilic substitution. The optimum yields of products in catalytic reaction were as high as approximately 100%.

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Александров, В., V. Aleksandrov, М. Морщилов, and M. Morshchilov. "Formation of wear resistant coatings on aluminum alloys by chromium deposition from gas-phase organometallic compounds." Science intensive technologies in mechanical engineering 1, no. 2 (February 28, 2016): 34–38. http://dx.doi.org/10.12737/17807.

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The method of coatings producing by chemical vapor deposition from gas phase by pyrolysis of organometallic com-pounds of chromium on the aluminum alloy AL9 is described. For the research the “Barhos” liquid with bis-arene chromium organic compounds, containing bis-ethylbenzene chromium (322 ºC boiling point, decomposition temperature of the metal is 330 ºC), was selected. The chromium content in the liquid is not less than 16%.The deposition process depends on the gas-phase chromium: substrate temperature, reactor pressure, evaporator temperature, process duration. The deposition temperature (substrate temperature) is one of the major factors in the formation of coatings. It is determined, that the pyrolytic chromium coatings are characterized by high hardness (up to 16000 MPa) and wear resistance due to the amorphous structure, which allows them to improve the wear resistance of rubbing parts.

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Kemp, Samuel A., Timothy J. Prior, Huguette Savoie, Ross W. Boyle, and Benjamin S. Murray. "The Application of Reversible Intramolecular Sulfonamide Ligation to Modulate Reactivity in Organometallic Ruthenium(II) Diamine Complexes." Molecules 25, no. 2 (January 7, 2020): 244. http://dx.doi.org/10.3390/molecules25020244.

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Metallation of biomacromolecular species forms the basis for the anticancer activity of many metallodrugs. A major limitation of these compounds is that their reactivity is indiscriminate and can, in principle, occur in healthy tissue as well as cancerous tissue, potentially leading to side effects in vivo. Here we present pH-dependent intramolecular coordination of an arene-tethered sulfonamide functionality in organometallic ruthenium(II) ethylenediamine complexes as a route to controlling the coordination environment about the central metal atom. Through variation of the sulfonamide R group and the length of the tether linking it to the arene ligand the acidity of the sulfonamide NH group, and hence the pH-region over which regulation of metal coordination occurs, can be modulated. Intramolecular sulfonamide ligation controlled the reactivity of complex 4 within the physiologically relevant pH-region, rendering it more reactive towards 5ʹ-GMP in mildly acidic pH-conditions typical of tumour tissue compared to the mildly alkaline pH-conditions typical of healthy tissue. However, the activation of 4 by ring-opening of the chelate was found to be a slow process relative to the timescale of typical cell culture assays and members of this series of complexes were found not to be cytotoxic towards the HT-29 cell line. These complexes provide the basis for the development of analogues of increased potency where intramolecular sulfonamide ligation regulates reactivity and therefore cytotoxicity in a pH-dependent, and potentially, tissue-dependent manner.

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38

Ibrahim, Mohamed, Fahad A. Al-Zahrani, Francisco J. Diaz, Tareq Al-Attas, Hasan Zahir, Syed A. Ali, Mohammed Abdul Bari Siddiqui, and Mohammad M. Hossain. "Experimental Investigation of Metal-Based Calixarenes as Dispersed Catalyst Precursors for Heavy Oil Hydrocracking." Catalysts 12, no. 10 (October 17, 2022): 1255. http://dx.doi.org/10.3390/catal12101255.

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Slurry-phase hydrocracking utilizing metal-containing oil-soluble compounds as precursors of dispersed catalysts is an effective approach for heavy oil upgrading. We propose applying metal-based p-tert-butylcalix[6]arene (TBC[6]s) organic species as dispersed catalyst precursors to enhance catalytic hydrogenation reactions involved in the upgrading of vacuum gas oil (VGO). Co- and Ni-based TBC[6]s were synthesized and characterized by SEM-EDX, ICP, XRD, and FT-IR. The thermogravimetric and calorimetric behaviors of the synthesized complexes, which are key properties of dispersed hydrocracking catalysts, were also explored. The experimental evaluation of the synthesized catalyst precursors show that the synthesized metal-based TBC[6] catalyst precursors improved the catalytic hydrogenation reactions. A co-catalytic system was also investigated by adding a commercial, first-stage hydrocracking supported catalyst in addition to the dispersed catalysts. The naphtha yields increased from 10.7 wt.% for the supported catalyst to 11.7 wt.% and 12 wt.% after adding it along with Ni-TBC[6] and Co-TBC[6], respectively. Mixing the metal-based precursors resulted in elevated yields of liquid products due to the in situ generation of highly active Co–Ni bimetallic dispersed catalysts.

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Okumura, Mikiko, and David Sarlah. "Arenophile-Mediated Photochemical Dearomatization of Nonactivated Arenes." CHIMIA International Journal for Chemistry 74, no. 7 (August 12, 2020): 577–83. http://dx.doi.org/10.2533/chimia.2020.577.

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Aromatic compounds are one of the most abundant classes of organic molecules and find utility as precursors for alicyclic hydrocarbon building blocks. While many established dearomatization reactions are exceptionally powerful, dearomatization with concurrent introduction of functionality, i.e. dearomative functionalization, is still a largely underdeveloped field. This review aims to provide an overview of our recent efforts and progress in the development of dearomative functionalization of simple and nonactivated arenes using arenophile-arene cycloaddition platform. These cycloadducts, formed via a visible-light-mediated [4+2]-photocycloaddition, can be elaborated in situ through olefin chemistry or transition-metal-catalyzed ring-opening with carbon-, nitrogen-, and oxygen-based nucleophiles, providing access to diverse structures with functional and stereochemical complexity. Moreover, the dearomatized products are amenable to further elaborations, which effectively install other functionalities onto the resulting alicyclic carbocycles. The utility of the arenophile-mediated dearomatization methods are also highlighted by the facile syntheses of natural products and bioactive compounds through novel disconnections.

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40

Lu, Bing-Bing, Xue Han, Cheng-Jie Feng, Duo Wang, and Fei Ye. "Two Co(II)-Based MOFs Constructed from Resorcin[4]Arene Ligand: Syntheses, Structures, and Heterogeneous Catalyst for Conversion of CO2." Crystals 11, no. 6 (May 21, 2021): 574. http://dx.doi.org/10.3390/cryst11060574.

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Two Co(II)-based metal–organic frameworks (MOFs) with open channels, [(CH3)2NH2]2[Co5L(H2O)8]·4H2O (1) and [Co6L(DMF)2(H2O)8]·2H2O (2), were synthesized using resorcin[4]arene ligand (H12L). Compounds 1 and 2 exhibit different 3D microporous framework structures: 1 possesses two kinds of open channels parallel to the a-axis (ca. 5.0 × 5.0 Å) and the b-axis (ca. 4.0 × 6.0 Å), and 2 is an open framework with a window size of 5.6 × 5.6 Å. The activated crystal 1 involves many Lewis acid sites; thus, 1 shows prominent activity and recyclability for the reaction of carbon dioxide coupled with epoxides. Most strikingly, catalyst 1 can be reused for five successive cycles and provides outstanding catalytic activity.

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41

Padnya, Pavel, Ksenia Shibaeva, Maxim Arsenyev, Svetlana Baryshnikova, Olga Terenteva, Igor Shiabiev, Artur Khannanov, et al. "Catechol-Containing Schiff Bases on Thiacalixarene: Synthesis, Copper (II) Recognition, and Formation of Organic-Inorganic Copper-Based Materials." Molecules 26, no. 8 (April 17, 2021): 2334. http://dx.doi.org/10.3390/molecules26082334.

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For the first time, a series of catechol-containing Schiff bases, tetrasubstituted at the lower rim thiacalix[4]arene derivatives in three stereoisomeric forms, cone, partial cone, and 1,3-alternate, were synthesized. The structure of the obtained compounds was proved by modern physical methods, such as NMR, IR spectroscopy, and HRMS. Selective recognition (Kb difference by three orders of magnitude) of copper (II) cation in the series of d-metal cations (Cu2+, Ni2+, Co2+, Zn2+) was shown by UV-vis spectroscopy. Copper (II) ions are coordinated at the nitrogen atom of the imine group and the nearest oxygen atom of the catechol fragment in the thiacalixarene derivatives. High thermal stable organic-inorganic copper-based materials were obtained on the base of 1,3-alternate + Cu (II) complexes.

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42

Schmidbaur, Hubert, Theodore Zafiropoulos, Wolfgang Bublak, Paul Burkert, and Frank H. Köhler. "High Resolution and Solid State NMR Investigations of Subvalent Gallium Compounds." Zeitschrift für Naturforschung A 41, no. 1-2 (February 1, 1986): 315–18. http://dx.doi.org/10.1515/zna-1986-1-258.

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The 71Ga NMR spectra of Ga[GaX4] melts and of solutions in benzene and other hydrocarbons show discrete sharp GaI and broad GaIII resonances. In the light of recent structure determinations, the solution GaI signals must be attributed to bis(arene)Ga+ complexes in which the gallium atom is η6-bonded to the hydrocarbons. The low line widths and strong high field shifts are attributed to an almost spherical shielding of the metal nucleus by the 4 s2 electrons. Solid state 69Ga and 71Ga NMR spectra of Ga[GaCl4] crystalline powder show only Ga1 resonances. While the 71GaI line is rather narrow, the 69GaI line has a complex fine structure. Consistent with the crystal structure of Ga[GaCl4], the Ga1 ion is calculated to have a very low quadrupole coupling constant e2q Q/h = 1.7 ± 0.1 MHz and an asymmetry parameter η = 0.44. Experimental and simulated line shapes (using literature models) are in satisfactory agreement, implying that the 69Ga signal splitting is due to second order quadrupolar effects for the central m = + 1/2 ⇋ - 1/2 transition. The analogous splitting of the 71Ga NMR line is too small to be detected.

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43

Ward, James, Li Li, Fiona Regan, Mary Deasy, and Fintan Kelleher. "Bis(spirolactam) 1,3-double-armed calix[4]arene compounds and their application as extractants for the determination of heavy metal ions." Journal of Inclusion Phenomena and Macrocyclic Chemistry 83, no. 3-4 (October 15, 2015): 377–86. http://dx.doi.org/10.1007/s10847-015-0574-z.

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44

Zaki, Mehvash, Suboot Hairat, and Elham S. Aazam. "Scope of organometallic compounds based on transition metal-arene systems as anticancer agents: starting from the classical paradigm to targeting multiple strategies." RSC Advances 9, no. 6 (2019): 3239–78. http://dx.doi.org/10.1039/c8ra07926a.

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45

Danil de Namor, Angela F., and Samir Chahine. "Solvation Effect of Guest, Supramolecular Host, and Host−Guest Compounds on the Thermodynamic Selectivity of Calix(4)arene Derivatives and Soft Metal Cations." Journal of Physical Chemistry B 109, no. 38 (September 2005): 18096–102. http://dx.doi.org/10.1021/jp053134d.

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46

Otsuka, Hideyuki, Yoshio Suzuki, Atsushi Ikeda, Koji Araki, and Seiji Shinkai. "Guest inclusion properties of calix[6]arene-based unimolecular cage compounds. On their high Cs+ and Ag+ selectivity and very slow metal exchange rates." Tetrahedron 54, no. 3-4 (January 1998): 423–46. http://dx.doi.org/10.1016/s0040-4020(97)10261-7.

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47

Mendoza-Ferri, Maria G., Christian G. Hartinger, Alexey A. Nazarov, Rene E. Eichinger, Michael A. Jakupec, Kay Severin, and Bernhard K. Keppler. "Influence of the Arene Ligand, the Number and Type of Metal Centers, and the Leaving Group on thein VitroAntitumor Activity of Polynuclear Organometallic Compounds." Organometallics 28, no. 21 (November 9, 2009): 6260–65. http://dx.doi.org/10.1021/om900715j.

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48

Sivkov, Danil, Olga Petrova, Alena Mingaleva, Anatoly Ob’edkov, Boris Kaverin, Sergey Gusev, Ilya Vilkov, et al. "The Structure and Chemical Composition of the Cr and Fe Pyrolytic Coatings on the MWCNTs’ Surface According to NEXAFS and XPS Spectroscopy." Nanomaterials 10, no. 2 (February 21, 2020): 374. http://dx.doi.org/10.3390/nano10020374.

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The paper is devoted to the structure and properties of the composite material based on multi-walled carbon nanotubes (MWCNTs) covered with pyrolytic iron and chromium. Fe/MWCNTs and Cr/MWCNTs nanocomposites have been prepared by the metal organic chemical vapor deposition (MOCVD) growth technique using iron pentacarbonyl and bis(arene)chromium compounds, respectively. Composites structures and morphologies preliminary study were performed using X-ray diffraction, scanning and transmission electron microscopy and Raman scattering. The atomic and chemical composition of the MWCNTs’ surface, Fe-coating and Cr-coating and interface—(MWCNTs surface)/(metal coating) were studied by total electron yield method in the region of near-edge X-ray absorption fine structure (NEXAFS) C1s, Fe2p and Cr2p absorption edges using synchrotron radiation of the Russian-German dipole beamline (RGBL) at BESSY-II and the X-ray photoelectron spectroscopy (XPS) method using the ESCALAB 250 Xi spectrometer and charge compensation system. The absorption cross sections in the NEXAFS C1s edge of the nanocomposites and MWCNTs were measured using the developed approach of suppressing and estimating the contributions of the non-monochromatic background and multiple reflection orders radiation from the diffraction grating. The efficiency of the method was demonstrated by the example of the Cr/MWCNT nanocomposite, since its Cr2p NEXAFS spectra contain additional C1s NEXAFS in the second diffraction order. The study has shown that the MWCNTs’ top layers in composite have no significant destruction; the MWCNTs’ metal coatings are continuous and consist of Fe3O4 and Cr2O3. It is shown that the interface between the MWCNTs and pyrolytic Fe and Cr coatings has a multilayer structure: a layer in which carbon atoms along with epoxy –C–O–C– bonds form bonds with oxygen and metal atoms from the coating layer is formed on the outer surface of the MWCNT, a monolayer of metal carbide above it and an oxide layer on top. The iron oxide and chromium oxide adhesion is provided by single, double and epoxy chemical binding formation between carbon atoms of the MWCNT top layer and the oxygen atoms of the coating, as well as the formation of bonds with metal atoms.

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Tu, Chuqiao, Dazhan Liu, Kazimierz Surowiec, David W. Purkiss, and Richard A. Bartsch. "Di-ionizable p-tert-butylcalix[4]arene-1,2-crown-5 and -crown-6 compounds in the cone conformation: synthesis and alkaline earth metal cation extraction." Organic & Biomolecular Chemistry 4, no. 15 (2006): 2938. http://dx.doi.org/10.1039/b604218j.

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Umemoto, Teruo, Lloyd M. Garrick, and Norimichi Saito. "Discovery of practical production processes for arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides): Beginning of a new era of “super-trifluoromethyl” arene chemistry and its industry." Beilstein Journal of Organic Chemistry 8 (March 29, 2012): 461–71. http://dx.doi.org/10.3762/bjoc.8.53.

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Various arylsulfur pentafluorides, ArSF5, have long been desired in both academic and industrial areas, and ArSF5 compounds have attracted considerable interest in many areas such as medicines, agrochemicals, and other new materials, since the highly stable SF5 group is considered a “super-trifluoromethyl group” due to its significantly higher electronegativity and lipophilicity. This article describes the first practical method for the production of various arylsulfur pentafluorides and their higher homologues, bis- and tris(sulfur pentafluorides), from the corresponding diaryl disulfides or aryl thiols. The method consists of two steps: (Step 1) treatment of a diaryl disulfide or an aryl thiol with chlorine in the presence of an alkali metal fluoride, and (step 2) treatment of the resulting arylsulfur chlorotetrafluoride with a fluoride source, such as ZnF2, HF, and Sb(III/V) fluorides. The intermediate arylsulfur chlorotetrafluorides were isolated by distillation or recrystallization and characterized. The aspects of these new reactions are revealed and reaction mechanisms are discussed. As the method offers considerable improvement over previous methods in cost, yield, practicality, applicability, and large-scale production, the new processes described here can be employed as the first practical methods for the economical production of various arylsulfur pentafluorides and their higher homologues, which could then open up a new era of “super-trifluoromethyl” arene chemistry and its applications in many areas.

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Journal articles on the topic 'Metal-arene compounds'

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