Synthesis, characterization and variable temperature NMR studies on coordination geometry of dimethytin(IV) S(+)-2-(4-isobutylphenyl)propanoate

Dimethytin(IV) S(+)-2-(4-isobutylphenyl)propanoate was synthesized and characterized by elemental analysis and IR and variable temperature NMR spectroscopy. Variable temperature NMR analysis was performed to see the effect of temperature on coordination geometry of organotin complexes in non-coordinating solvent. Spectral data has shown that temperature change does not alter the coordination geometry of the complex, and that it remains greater than four at variable temperatures as well as at room temperature in solution state. This text was submitted by the authors in English.     

Structural chemistry of organotin(IV) complexes

The amazing structural diversity in organotin compounds is discussed in the systems containing -O and -S donor ligands. It is demonstrated that there exist a fascinating range of structural diversity for organotin(IV) complexes, including differences in coordination number and molecular geometry. The difference in structure is correlated with the nature of tin and ligand bonded R groups. Despite the large number of different structures found in organotin(IV) carboxylates, there is limited range of coordination geometries about the Sn atom. The four coordinated Sn atom in triorganotin(IV) complexes is invariably distorted tetrahedral and five coordinated Sn is distorted trigonal bipyramidal. A large range has been observed for diorganotin carboxylate structures, where five, six and seven coordinate geometries have been reported. The Sn atom in mono-organotin has only been demonstrated to exist in distorted octahedral geometries (the single exception being a pentagonal bipyramidal geometry). In the case of organotin(IV) complexes of S donor ligands, it has been shown that there exists a rich diversity in Sn atom geometries and coordination modes of the sulfur donor ligands themselves. As in related carboxylate systems, the assignment of coordination numbers to the Sn centers in some compounds is controversial. As a general trend, it has been shown that, the overall coordination number at the Sn atom decreases with the increasing number of organic substituents at the Sn atom. This phenomenon is usually achieved by increased asymmetry in the mode of coordination of the sulfur donor ligands.     

Organotin(IV) complexes of 4,5-dimethoxy-2-nitrobenzoic acid: Synthesis,characterization, and biological activity

A new series of organotin esters has been derived from the condensation of organotin oxides/halides with 4,5-dimethoxy-2-nitrobenzoic acid. Their spectroscopic investigations have been carried out both in solution and solid state. Experimental details for the preparation and the structural characterization (by FTIR, NMR, XRD, and EI mass spectral analysis) are provided. Based on spectroscopic results, the ligand appeared to coordinate to the Sn atom through the COO moiety. Single crystal analysis has shown a bridging behavior of ligand in tributyltin(lV) derivative. Bioassay results have shown that these compounds have good antibacterial, antifungal and cytotoxicity activity, with few exceptions.     

Coordination behavior of the carboxylate group in organotin(IV) derivatives of 2-[(2′,4′,6′-tribromophenylamido)]benzoic acid and 3-[(2′,4′,6′-tribromophenylamido)]propenoic acid: Spectroscopic studies

The complexes of two organic carboxylates (containing {O,O}-donor atoms) with Me₂Sn^(IV)Cl₂, n-Bu₂Sn^(IV)Cl₂, Bz₂Sn^(IV)Cl₂, Oct₂Sn^(IV)O, Me₃Sn^(IV)Cl, n-Bu₃Sn^(IV)Cl, Ph₃Sn^(IV)Cl, Ph₃Sn^(IV)Cl, and Bz₃Sn^(IV)Cl having ligand-to-metal ratios of 1: 2 and 1: 1 were prepared by two different methods. The FT-IR spectra clearly demonstrated that organotin(IV) moieties react with {O,O}-atoms of the ligands. It was found that in all cases the COO⁻ group was acting as bidentate in the solid state. The ¹¹⁹Sn NMR data revealed that the organotin(IV) moiety has a tetrahedral geometry in non-coordinating solvents. The biological activity of these compounds was compared with that of their precursors, and all the synthesized compounds show significant antibacterial activity. The antifungal activity of the complexes against six plant pathogens has been estimated. The complexes display marked toxicity against these fungi and are more fungitoxic than free acids. The compounds have also shown significant cytotoxicity against Brine Shrimp (Artemia salina). The article was submitted by the authors in English.     

Synthesis, characterization and crystal structure of bis(acetylacetonato)dichlorotin(IV)

The compound bis(acetylacetonato)dichlorotin(IV) [Sn(acac)₂Cl₂] forms a distorted octahedral structure involving both oxygen atoms of the acetylacetone group. The two chlorides occupy the cis position, with Sn-Cl distances of Sn1-Cl1 = 2.380(2) Å, Sn1-O1 = 2.043(2) Å and Sn1-O2 = 2.093(2) Å. We report here a new and simple method for the synthesis of Sn(acac)₂Cl₂, its spectroscopic characterization and, for the first time, we report its crystal structure.     

Coordination chemistry of the transition metal carboxylates synthesized from the ligands containing peptide linkage

Transition metal carboxylates, i.e., 3-[(2,4,6-trichloroanilino)carbonyl]prop-2-enoic acid and 3-[(4-bromoanilino)carbonyl]prop-2-enoic acid have been synthesized. The unimolar and bimolar substituted products have been characterized by elemental analysis, IR, UV-Vis spectroscopy, ¹H NMR, and atomic absorption. IR data show the bidentate nature of the carboxylate group. The transition metal complexes were tested in vitro against a number of microorganisms to assess their biocidal properties. The text was submitted by the authors in English.     

Synthesis,spectroscopic, theoretical study,and biological activities of vanadium(IV) and vanadium(V) complexes with isonipecotic acid

Russian Journal of General Chemistry - Vanadium(IV) and vanadium(V) complexes 1–7 have been synthesized by the reaction of isonipecotic acid with VOSO4 · 3 H2O, VCl3(THF)3, and NH4VO3 at...     

Synthesis of stannic(IV) complexes: Their structural elucidation in solid and solution state and antimicrobial activity

A series of organotin(IV) thiocarboxylates have been synthesized with the general formula R₂SnL₂ and R₃SnL (R = Ph₂(I), Me₃(II), n‐Bu₃(III), Ph₃(IV), Cy₃(V), Me₂(VI), n‐Bu₂(VII), and L = piperidine‐1‐thiocarboxylic acid) in anhydrous toluene under the reflux conditions. The complexes were characterized by microanalysis, IR, ¹H and ¹³C NMR, mass spectrometry, and XRD. NMR data revealed that thiocarboxylic acid acts as bidentate, and complexes exhibit the four‐coordinated geometry in solution state. In solid state, diorganotin complexes exhibit the hexa‐coordinated geometry whereas the triorganotin(IV) compounds show the five‐coordinated geometry. These complexes were also tested for their antimicrobial activity along with the ligand against different animals, plant pathogens, and Artemia salina. All complexes with few exceptions show high activity as compared to the ligand. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:664–674, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20380     

Crystal structure of 1,1-dibutyl-1,1-bis[(4-methyl-1-piperidinyl)dithiocarbamato)] tin(IV)

The dibutyltin(IV) complex of 4-methyl-1-piperidinedithioic acid has been synthesized and characterized by X-ray diffraction. It was found that tin atom has distorted tetragonal geometry with the space group P-1.