N.S. Yashina

The effect of solvent upon the rates and mechanisms of organometallic reactions : III. nqr specta and structures of molecular complexes of methyltin halides and tin tetrahalides

Abstract NQR spectra have been obtained for molecular complexes of methyltin halides or tin tetrahalides containing various electron-donating molecules. The structures have been shown to be a function of the number of methyl groups and halogens present in the methyltin halides and of the nature of the electron donor. An anomalous temperature dependence of the NQR frequencies has been observed in some cases.

The effect of solvent upon the rates and mechanisms of organometallic reactions. : II. Molecular complexes of methyltin halides and tin tetrahalides

Methyltin halides give solid molecular complexes with the organic solvents normally employed in organometallic chemistry. Me3SnBr gives complexes of the type Me3SnBr·L with monodentate ligands (Py, DMSO, DMF, HMPT) and complexes of the type 2Me3SnBr·L with bidentate ligands (dioxane, TMED). Me2SnHal2, MeSnHal3 and SnHal4 give complexes containing either two monodentate ligands or one bidentate ligand.

The effect of the solvent upon the rates and mechanisms of organometallic reactions : V. PMR spectra and structure of molecular complexes of methyltin halides in solutions

The complexation of methyltin halides in electron-donating solvents such as acetone, dioxane, dimethoxyethane, pyridine, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide, and tetramethylethylenediamine has been studied by means of PMR spectroscopy. Equilibrium constants have been evaluated for Me3SnHal·D (D = donor) complexes. The concentration and temperature dependences of J(119SnC1H) in methyltin halides suggest some conclusions on the electron and spatial structures of complexes in solutions.Abstract The complexation of methyltin halides in electron-donating solvents such as acetone, dioxane, dimethoxyethane, pyridine, dimethylformamide, dimethyl sulfoxide, hexamethylphosphoric triamide, and tetramethylethylenediamine has been studied by means of PMR spectroscopy. Equilibrium constants have been evaluated for Me3SnHal·D (D = donor) complexes. The concentration and temperature dependences of J(119SnC1H) in methyltin halides suggest some conclusions on the electron and spatial structures of complexes in solutions.

Synthesis and structure of diethyltindichloride methylenediphosphinato complex: Et2SnCl2 · [Me(i PrO)P(O)]2CH2☆

In the title complex the disphosphinato ligand coordinates in a chelate mode to give a distorted octahedral environment at tin with the ethyl groups in a trans position.

Synthesis and structures of some diethyl- and diphenyltin bishydroxamates

Abstract Diethyl- and diphenyltin derivatives of N-methyl-N-p-bromobenzoylhydroxylamineR2Sn{ON)C6H4Br-p)C(O)C6H4Br-p}2, R=Et, Ph, and N-p-bromophenyl-N-p-bromobenzoylhydroxylamine, R2,Sn{ON(C6H4Br-p)C(O)C6H4Br-p} 2, R = Et, Ph, were made and characterized by IR, Mossbauer and NMR (1H, 13C, 119Sn) spectroscopy and, in the case of EtPin2Sn{ON(Me)C(O)C6H4Br-p}2, by an X-ray diffraction study. The geometry at the tin atom is that of a distorted trans octahedron with two bidentate, nearly equivalent, N-acylhydroxylamine residues and a CSnC angle of 141.1°. On the basis of the Mossbauer data for the diphenyltin hydroxamates, a cis-octahedral structure with bidentate ligation of the hydroxylamine residues is suggested.

Synthesis and structure of 1 : 1 complex of dimethyltin dichloride with meso-1,2-bis(α-diethoxyphosphorylbenzylamino)ethane

Abstract The crystal and molecular structure of the title compound has been determined by single crystal X-ray analysis. The complex is polymeric, the ligand coordinating in a bridging mode via two phosphoryl groups. The coordination environment at tin is octahedral with two methyl groups, two chlorine and two oxygen atoms occupying trans positions.

Syntheses, Structures and Biological Activites of Organogermaniun and Organotin Derivatives of Hydroxamic Acids

OF ORGANOGERMANIUM AND ORGANOTIN DERIVATIVES OF HYDROXAMIC ACIDS Valery S. Petrosyan*, Natalia S. Yashina, and Sergei V. Ponomarev Department of Chemistry, M. V. Lomonosov University, Moscow 119899, Russia Hydroxamic acids as the precursors oftheir organogermanium and organotin derivatives have been themselves intensively studied fi’om the viewpoint of their potential biological activities [1-3]. The wide spectrum of biological activities, from fungicide, bactericide and antiflammatory to psychotropic and antitumor, has been demonstrated for various organic derivatives of hydroxamic acids. Mironov and coworkers [4] at first obtained the C-germylated hydroxamic acids with about 70% yield by the reaction of the methyl ester of 3-trimethylgermylpropionic acid with hydroxylamine chlorohydrate: 0C Me3GeCH2CH2COOCH3 + NH2OH HC1 Me3GeCH2CH2CONHOH HC1 KOH

Syntheses and solid-state structures of some dialkyltin derivatives of α-methoxy- and α-acetoxy-phenylacetic acids

Several di-n-butyltin and diethyltin biscarboxylates and distannoxanes of α-methoxy- and α-acetoxy-phenylacetic acids were synthesized and (two of) their structures were studied by means of X-ray diffraction analysis as well as by means of IR and Mossbauer spectroscopies. It was shown for {[(n-Bu) 2 - SnOC(O)CH(OMe)Ph] 2 O} 2 that there is an interaction between the OMe group and one of the endocyclic tin atoms, resulting in a distorted pentagonal-bipyramidal geometry with the pentagonal plane defined by five O atoms and an uncommon seven coordination number for this tin atom. Spectral data indicate that biscarboxylates have trans-octahedral structures.

X-Ray structure investigation of trimethyltin α-phenyl-α-oxoacetate

Abstract X-Ray structure investigation of trimethyltin α-phenyl-α-oxoacetate Me 3 SnOC(O)CH(OH)Ph was carried out. The unit cell contains two independent molecules with practically identical conformation. Molecules are associated in the chains due to coordination bonds between the oxo-group and the tin atom of the neighbouring molecule. The chains in the crystal are connected with one another by hydrogen bonds between oxo-group protons and carboxyl oxygen atoms.

Cis- and trans-influences in octahedral complexes of methyltin trihalides and tin tetrahalides with tertiary phosphines

Abstract By analysis of 1 J ( 119 Sn 31 P) coupling constants for complexes of methyltin trihalides and tin tetrahalides with mono- and bi-dentate tertiary phosphines, it is proposed that strengthening of the SnP bonds occurs when the phosphine is situated in a trans -position to the most electron-donating substituent, and it is accompanied by a concomitant weakening of the cis -SnP bond.