共查询到20条相似文献,搜索用时 31 毫秒
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Giampaolo Barone Marina Cotta Ramusino Renato Barbieri Gianfranco La Manna 《Journal of Molecular Structure》1999,469(1-3):143-149
The interaction between a dinucleotide triphosphate duplex (DD), mimicking the DNA molecule, and the dimethyltin(IV) cation is studied by the semiempirical PM3 method. The results show that the interaction can occur involving the tin atom and the electron-donor centres of DD, requiring in some cases the presence of water molecules. In particular, the binding of the dimethyltin(IV) moiety with two adjacent phosphate oxygen atoms is allowed by the presence of water molecules coordinating to the tin atom. In this case the tin environment shows a geometry in agreement with 119Sn Mössbauer and X-ray data. 相似文献
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《Journal of Coordination Chemistry》2012,65(6):1101-1114
The interaction of dimethyltin(IV) dichloride (DMT) with 1,4-piperazine (PIP) was investigated. The complex formation equilibria of the complexes formed in solution were investigated. The stoichiometry and stability constants of the complexes formed in solution phase were determined at different temperatures and in solutions of dioxane–water mixtures of different dielectric constants. The equilibrium constant for the displacement of piperazine coordinated to dimethyltin(IV) by inosine as a representative of DNA was calculated. (DMT)(PIP)·3H2O was synthesized and characterized by elemental analysis, spectral, and thermal techniques. The antitumor activity of the complex was screened. 相似文献
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The interaction between imidazole (L1), 2-isopropylimidazole (L2), 2-amino-benzimidazole (L3) and 2-(2-pyridyl)benzimidazole (L4) (L in general), and dimethyltin chloride in water have been investigated at 25 degrees C and ionic strength of 0.1 M sodium nitrate using the potentiometric technique. The results showed the formation of 1:1 and 1:2 (organotin:ligand) complexes and the corresponding stability constants were determined. The effect of the pKa values of the respective ligands on the stability constants of its complex species was elucidated. The concentration distribution of the complexes in solution was evaluated. Also, their solid complexes of the general formula in diethylether-dichloromethane, give 1:2 (organotin:Ligand) [(L)2 (CH3)2 SnCl2.zH2O][L = L1, z = 0 and L = L2, z = 1] and 1:1 [L (CH3)2 SnCl2.zH2O][L = L3, z = 0 and L = L4, z = 2]. The separated solid products were characterized by elemental analyses (C, H, N, Cl), IR, mass spectra, thermogravimetric analysis (TGA) and magnetic susceptibility. The participation of the ligand functional groups in bonding to the organotin (IV) was discussed. Conductivity and 1H-NMR spectra were used to confirm the behaviour of these complexes in solution. 相似文献
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Abida Kalsoom M. Mazhar Saqib Ali M. F. Mahon K. C. Molloy M. Iqbal Chaudry 《应用有机金属化学》1997,11(1):47-55
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《Journal of Coordination Chemistry》2012,65(7):1240-1253
The complex-formation equilibria of dimethyltin(IV) (DMT) with 4-hydroxymethyl imidazole (HMI) and 2,6-dihydroxymethyl pyridine (PDC) have been investigated. Stoichiometry and stability constants for the complexes formed were determined at different temperatures and 0.1?mol?L?1 NaNO3 ionic strength. The concentration distribution of the complexes in solution was evaluated as a function of pH. The effect of dioxane as a solvent on both protonation constants and formation constants of DMT complexes with HMI and PDC are discussed. The thermodynamic parameters ΔH° and ΔS° calculated from the temperature dependence of the equilibrium constants were investigated. 相似文献
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Aglaia Koutsodimou Nikos Katsaros Dimitra Kovala-Demertzi 《Transition Metal Chemistry》1994,19(3):260-264
Summary The effect of RhCl3 on DNA helix conformation was studied by circular dichroism spectroscopy and compared to the behaviour of Me2SnCl2 and TINO3; the latter metal-DNA systems have been further studied by ultraviolet and thermal denaturation techniques. Both rhodium(III) and tin(IV) react with the bases of DNA and induce appreciable alterations of the double-helical conformation. Rhodium(III) at low binding ratio causes a stabilization of the DNA B conformation, while at higher structural changes are interpreted in terms of a B to C transition. Tin(IV) produces a form geometry; only at high binding ratios does interaction with the phosphate groups seem to occur. The data for thallium(I) are interpreted in terms of a preferential interaction with the phosphate groups of the DNA chain, causing a stabilization of the double-helical structure of DNA. 相似文献
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Some five-coordinated dimethyltin(IV) complexes of the type Me2SnL (where L is the anion of a bifunctional tridentate Schiff base) were synthesized. These Schiff bases are N-(3-hydroxypyridine-2-yl)-3-methoxysalicylideneimine, HOC6H3OCH3CH=NC5H3NOH (1), N-(3-hydroxypyridine-2-yl)-3-ethoxysalicylideneimine, HOC6H3OC2H5CH=NC5H3NOH (2), N-(3-hydroxypyridine-2-yl)-5-chlorosalicylideneimine, HOC6H3ClCH=NC5H3NOH (3), and N-(3-hydroxypyridine-2-yl)-3-methoxy-5-bromosalicylideneimine, HOC6H2OCH3BrCH=NC5H3NOH (4). Dimethyltin(IV) complex of 3 (3a) was characterized by single crystal X-ray diffraction method and a coordination geometry that is nearly halfway between
trigonal–bipyramidal and square pyramidal arrangement was found. Dimethyltin complexes of (1), (2), and (4) were also prepared and characterized by the comparison of their elemental analysis and 1H-NMR-, IR-, UV- and mass spectral data with those of (3a). For example, in the 1H-NMR spectra, the 2J(119Sn-1H) in the Sn-CH3 moiety have values between 80 Hz and 90 Hz, typical of five-coordinated tin species. By using these values in Lockart’s Equations,
H3C–Sn–CH3 angles in the complexes were estimated to lie between 130° and 145°. X-ray diffraction value for 3a, confirms this estimate within 3.4% relative deviation (129.7° exp. Vs. 134.9° estimate). 相似文献
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P. Tavridou U. RussoG. ValleD. Kovala-Demertzi 《Journal of organometallic chemistry》1993,460(2):C16-C18
The results of a single-crystal X-ray diffraction study of the 1:2 adduct between dichlorodimethyltin(IV) and 2-imidazolidone are reported, together with some preliminary IR data. The complex is hexacoordinate and with a distorted cis-octahedral geometry. 相似文献
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《Journal of Coordination Chemistry》2012,65(7):1115-1126
A UV-Vis spectrophotometric study of adduct formation of SalenH2 (1) and MII(Salen), where M?=?Mn (2), Fe (3), Co (4), Ni (5) and Cu (6) as donors with Me2SnCl2 as acceptor have been investigated in chloroform. Adducts (1a–6a) have been characterized by 1H, 13C and 119Sn NMR, IR and electronic spectroscopy and microanalysis. Formation constants and thermodynamic parameters were measured for 1 : 1 and 2 : 1 adducts at various temperatures (T?=?278 to 308 K). The data refinement was carried out with the SQUAD 84 program. The trend of formation constants of MII(Salen) complexes with Me2SnCl2 follows the order: Mn>Fe>Cu>Co>Ni. The formation constants for the free 1 and MII(Salen) with Me2SnCl2 changes according to the following trend: MII(Salen)>SalenH2 相似文献
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Abedien Zabardasti Ali Kakanejadifard Mozaffar Asadi 《Journal of heterocyclic chemistry》2006,43(5):1157-1160
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Georgina M. Rosair Dilip Kumar Dey Brajagopal Samanta Samiran Mitra 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(4):m266-m267
The structure of the title dimethyltin(IV) complex, [2‐(5‐bromo‐2‐oxidobenzylideneamino)benzoato‐κ3O,N,O′]dimethyltin(IV), [Sn(CH3)2(C14H8BrNO3)], features centrosymmetric dimers disposed about a central Sn2O2 core. Each Sn centre has seven‐coordinate pentagonal–bipyramidal geometry, taking into account two moderately long Sn—O contacts about an inversion centre [2.679 (4) and 2.981 (4) Å]. The methyl groups are in an axial orientation. 相似文献