Search results for "Coordination geometry"
showing 10 items of 100 documents
Crystal and solution structures of di-n-butyltin(IV) complexes of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol and benzoic acid derivatives: E…
2009
Abstract Reactions of nBu2SnCl(L1) (1), where L1 = acid residue of 5-[(E)-2-(4-methoxyphenyl)-1-diazenyl]quinolin-8-ol, with various substituted benzoic acids in refluxing toluene, in the presence of triethylamine, yielded dimeric mixed ligand di-n-butyltin(IV) complexes of composition [nBu2Sn(L1)(L2–6)]2 where L2 = benzene carboxylate (2), L3 = 2-[(E)-2-(2-hydroxy-5-methylphenyl)-1-diazenyl]benzoate (3), L4 = 5-[(E)-2-(4-methylphenyl)-1-diazenyl]-2-hydroxybenzoate (4), L5 = 2-{(E)-4-hydroxy-3-[(E)-4-chlorophenyliminomethyl]-phenyldiazenyl}benzoate (5) and L6 = 2-[(E)-(3-formyl-4-hydroxyphenyl)-diazenyl]benzoate (6). All complexes (1–6) have been characterized by elemental analyses, IR, 1H,…
Synthesis, characterization, and cytotoxic activity of copper(II) and platinum(II) complexes of 2-benzoylpyrrole and X-ray structure of bis[2-benzoyl…
2004
Copper(II) and platinum(II) complexes of 2-benzoylpyrrole (2-BZPH) were synthesized and characterized with IR, 1 H and 1 3 C NMR spectroscopies and coordination geometry with ligands arranged in transoid fashion. The crystal structure of [Cu I I (2-BZP) 2 ] was determined by X-ray diffraction. Death of complex treated Jurkat cells was measured by flow cytometry. The bis-chelate complexes [Cu I I (2-BZP) 2 ] and [Pt I I (2-BZP) 2 ] adopt square-planar coordination geometry with ligands, arranged in transoid fashion. Concentrations of 1-10 μM Platinum(II) complexes reduced cell survival from 100% to 20%, in contrast to the copper(II) complex which caused no cell death at a concentration of 10…
Hydroxo Hydrido Complexes of Iron and Cobalt (Sn−Fe−Sn, Sn−Co−Sn): Probing Agostic Sn⋅⋅⋅H−M Interactions in Solution and in the Solid State
2000
Bis(toluene)iron 9 reacts with Lappert's stannylene [Sn[CH(SiMe3)2]2] (4) to form the paramagnetic bis-stannylene complex [[(eta6-toluene)Fe-Sn-[CH(SiMe3)2]2]2] (10). Compound 10 reacts with H2O to form the hydroxo hydrido complex [(eta6-C7H8)(mu-OH)(H)-Fe-[Sn[CH(SiMe3)2]2]2] (12) in high yield; its solid-state structure has been elucidated by X-ray and neutron diffraction analysis. In agreement with the 1H NMR results, 12 contains a hydridic ligand whose exact coordination geometry could be determined by neutron diffraction. The 1H and 119Sn NMR analysis of 12 suggested a multicenter Sn/Sn/H/Fe bonding interaction in solution, based on significantly large values of J(Sn,H,Fe) = 640+/-30 Hz…
INTERACTIONS OF ORGANOTIN(IV) HALIDES WITH REDUCED GLUTATHIONE IN AQUEOUS-SOLUTION
1993
Abstract Glutathione (GSH) is a compound extremely common among many living organisms in which it plays a fundamental role in the processes of detoxification. Also, organotin(IV) derivatives are more and more commonly used in technological processes or as antitumor drugs. So it seemed interesting to investigate the possible interactions between GSH and organotin compounds in water. Particularly, it has been studied because of its role in the organic radicals linked to the tin center on the stoichiometry and the structure of the adducts. Information was obtained following the reaction between Me n SnCl 4-n (n = 1 to 3) and GSH by Mossbauer and NMR spectroscopies on the assumption that change…
Mixed-ligand copper(ii)–sulfonamide complexes: effect of the sulfonamide derivative on DNA binding, DNA cleavage, genotoxicity and anticancer activity
2013
Four ternary complexes, [Cu(L1)2(bipy)] (1) [HL1 = N-(6-chlorobenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L2)2(bipy)] (2) [HL2 = N-(benzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L3)2(bipy)]·1/2H2O (3) [HL3 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide] and [Cu(L4)2(bipy)] (4) [HL4 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)benzenesulfonamide], were prepared and then characterized by X-ray crystallography, spectroscopy and magnetic measurements. Whereas the molecular structure of 1 and 2 consists of a discrete monomeric copper(II) species with a distorted square planar geometry, that of 3 and 4 consists of two independent molecules. In 3, both molecules pre…
Magnetostructural correlations in parallel square-planar halo-bridged copper(II) dimers. Part II: Structure and magnetic properties of [Cu2(terpy)2Br…
1987
Abstract The crystal and molecular structure of bis-μ- bromo-bis [(2,2′:6′,2″ - terpyridyl) copper (II) ] bis (hexafluorophosphate) has been determined from three dimensional single-crystal X-ray diffraction data, collected by counter techniques. The blue crystals belong to the monoclinic system, space group P21/a, with four formula units in a unit cell of dimensions a=20.40(2), b=13.35(2), c=6.453(8) A and β=97.74(9)°. The structure was solved using a refinement procedure and starting with the atomic positions of the isostructural complex [Cu(terpy)- Cl]2(PF6)2, to final agreement factors R=0.071 (Rw=0.077). The structure consists of dimeric molecules bridged by two bromine atoms. The coor…
Unprecedented heptacopper(ii) cluster with body-centred anti-prismatic topology. Structure, magnetism and density functional study
2011
Using a (2-pyridyl)ethylamine-appended carboxylate ligand a new cluster [Cu(II)(7)(L)(4)(μ(3)-OH)(2)(H(2)O)(2)(DMF)(2)][ClO(4)](4)·4H(2)O (1) [L(2-): N-{CH(2)CH(2)(2-pyridyl)}(CH(2)CH(2)CO(2))(2)] is synthesized, as a result of 'coordination-driven self-assembly'. The structure of 1 is unique and consists of a centrosymmetric carboxylato- and hydroxo-bridged heptanuclear copper(II) cation, with body-centred anti-prismatic topology. The four crystallographically independent copper(II) centres differ markedly in their coordination geometry. In addition to establishing cluster authenticity, the structural analysis of 1 discloses two notable features. The existence of {Cu(II)(3)(μ(3)-OH)}(5+) c…
Synthesis and mössbauer studies of some aquo complexes of tin(IV) with crown ethers
1984
Abstract The preparation, characterization, and 119Sn Mossbauer spectra of a number of tin(IV) complexes with cyclic polyethers are presented. With tin(IV) chloride and methyltin(IV) trichloride, 1:1 and 2:1 metal-to-crown-ether complexes are formed, while dimethyltin(IV) dichloride forms only 2:1 complexes; in every case, two water molecules are present in the solid state structure. An octahedral coordination geometry around the tin(IV) center is proposed on the basis of Mossbauer and IR spectra.
Crystal structure and spectroscopic study of [Cu(BPCA)(OH2)(O2CCH3)·H2O complex; BPC = N-2-pyridinylcarbonyl-2-pyridinecarboximidate anion
1989
Abstract The crystal and molecular structure of the [Cu(BPCA)(OH2)(O 2CCH3]·H2O complex (BPCA = N-2-pyridinylcarbonyl-2-pyridinecarboximidate anion) has been determined by X-ray diffraction methods. It crystallizes in the triclinic space group P l with two formula units in a cell of dimensions: a = 7.416(2), b = 8.632(4), c = 13.034(3) A, α = 74.55(3), β = 84.84(3), γ = 81.04(5)°. Least-squares refinement of 2534 reflections with I > 2.5σ(I) and 218 parameters gave a final R = 0.047 and Rw = 0.049. The structure consists of discrete [Cu(BPCA)(OH2)(O2CCH3)] neutral units linked through hydrogen bonding. The coordination geometry around copper ions can be described as tetragonal square pyrami…
One-dimensional oxalato-bridged copper(II) complexes with 3-hydroxypyridine and 2-amino-4-methylpyridine
2001
Two new one-dimensional oxalato-bridged copper(II) compounds of formula [Cu(ox)L2]n (1) and {[Cu2(ox)2L%3]·L%}n (2) [ox oxalate dianion, L3-hydroxypyridine (pyOH) and L% 2-amino-4-methylpyridine (ampy)] have been synthesized and characterized by FT-IR spectroscopy, variable-temperature magnetic measurements and single-crystal X-ray diffraction. The crystal structure of 1 comprises chains of copper atoms in which cis-[Cu(pyOH)2] 2 units are sequentially bridged by asymmetric bis-bidentate oxalato ligands with an intrachain copper‐copper separation of 5.548(1) A, . Each copper atom is six-coordinated: four oxygen atoms belonging to two bridging oxalato ligands and two nitrogen atoms from two …