The structure of bis(trialkyltin) carbonates: Evidence for two non-equivalent tin sites

Bis(tributyltin) oxide or trimethyltin hydroxide react with carbon dioxide to afford the bis(trialkyltin) carbonates, (R₃SnO)₂CO; ¹¹⁹Sn NMR (in the case of R = Bu) or ^119mSn Mössbauer spectroscopy show that these compounds contain 4- and 5-coordinate tin atom sites.     

The preparation and tin-119m mössbauer spectra of tri-n-butylstannyl esters of heterocyclic and substituted aromatic carboxylic acids

The ^119mSn Mössbauer and infrared data are reported for fifteen tributyltin carboxylates. Although the Mössbauer data at 80 K shows them all to be pentacoordinate polymers, the infrared data indicates that, at room temperature, some of the compounds exist as tetracoordinate monomeric species.     

Synthesis and Characterization of Biologically Potent Di‐organotin(IV) Complexes of Mono‐Methyl Glutarate

The synthesis and characterization of some novel compounds of organotin(IV) chlorides with monomethyl glutarate is reported; the ligand molecule appears to be bound to the tin atom through the carbonyl oxygen. The results obtained through ¹H‐¹³C‐¹¹⁹Sn NMR, FT‐IR and ¹¹⁹Sn Mössbauer spectra show that the diorganotin(IV) complexes have hexacoordination with octahedral geometry. Biological screening of the complexes reveals that the diorganotin(IV) complexes show significant activity against all microorganisms.     

Studies on C-heterocyclic tin compounds. The synthesis and spectral characterization of some thienyl tetraorganotin(IV) compounds

The synthesis of a series of tetraorganotin(IV) compounds containing selectively the 2-thienyl, 3-thienyl, 5-methyl-2-thienyl, 5-t-butyl-2-thienyl, 4-methyl-2-thienyl and 3-(2-pyridyl)-2-thienyl groups [L], of formula R_4-nSn[L]_n (R = Ph, p-tolyl, Me, cyclopentyl, cyclohexyl; n = 1–4) is reported. Features of structural interest deduced from ^119mSn Mössbauer and NMR (¹³C and ¹¹⁹Sn modes) spectra are considered.     

Synthesis, 119Sn Mössbauer spectroscopic studies and X-ray crystal structure determination of new seven-coordinate diorganotin(IV) complexes with S,N,N,N,S-pentadentate Schiff bases derived from 2,6-diacetylpyridine of S-methyl- and S-benzyldithiocarbazates

The reactions of the ligands 2,6-diacetylpyridine bis(S-methyldithiocarbazate)] (H₂dapmdtc) and 2,6-diacetylpyridine bis(S-benzyldithiocarbazate)] (H₂dapbdtc) with R_4-m SnCl _m (R = Me, ⁿ Bu, Ph; and m = 2) led to the formation of six seven-coordinate diorganotin(IV) complexes, which were studied by microanalysis, i.r., n.m.r (¹H, ¹¹⁹Sn) and Mössbauer spectroscopies. The X-ray structures determination of complexes [Me₂Sn(dapmdtc)], [Me₂Sn(dapbdtc)] and [Ph₂Sn(dapbdtc)] revealed the presence of neutral seven-coordinated complexes. The structures consist of monomeric units in which the Sn(IV) atom exhibits distorted pentagonal bipyramidal (PBP) geometry, with the S,N,N,N,S-donor systems of the ligands lying in the equatorial plane and organic groups in the apical positions. A correlation between Mössbauer and X-ray data based on the point-charge model is discussed.     

Mössbauer-Messungen an Sn2O3

Mössbauer Studies on Sn₂O₃ Mössbauer data for ¹¹⁹Sn in Sn₂O₃ show this compound to contain bivalent and tetravalent tin. Whereas tin(IV) is coordinated in a similar way in Sn₂O₃ and SnO₂, a rather large quadrupole splitting indicates an environment of low symmetry for tin(II).     

Synthesis of tetravalent metal antimonates: Characteristics and use in treatment of radioactive waste solutions

Eight di-n-butyltin(IV) complexes with glycolic, 2-hydroxy-propionic, succinic and malic acids, have been prepared by two different procedures. The compounds were characterised by elemental analysis, FTIR, Raman and¹¹⁹Sn Mössbauer spectroscopy. The IR and Raman data indicated the presence of bidentate and/or monodentate carboxylate groups, non linear C?Sn?C bonds, and Sn?O bonds within the complexes. The results of Mössbauer spectroscopic measurements, based on point-charge model calculations, have shown the occurrence of trigonal bipyramidal environment in the central tin(IV) atom, besides the octahedral and tetrahedral structure.     

Vibrational and 119Sn Mössbauer Study of Tin Tetrahalide Complexes with Benzofuroxan Derivatives

The reactions of SnX₄ (X = Cl, Br) with benzofuroxan and some substituted derivatives are studied, and the hexacoordinated complexes SnCl₄(Y-C₆H₃N₂O₂)₂ (Y = H, Cl, Me, OMe), and SnBr₄ (Y-C₆H₃N₂O₂)₂ (Y = H, OMe) have been isolated. The adducts are studied by IR, Raman, and ¹¹⁹Sn Mössbauer spectroscopies, which suggest a cis structure (C_2v symmetry) for them. The good correlation between υ Sn? Cl (IR and Raman spectra) and the Mössbauer quadrupole splitting for the SnCl₄ complexes, supports the consistency of the structural assignments. The Mössbauer spectra show resolved quadrupole doublets, in spite of the cis structure of the adducts, which emphasizes the fact that the resolvable or unresolvable nature of the doublets cannot be used confidently to elucidate the structure of tin tetrahalide complexes.     

Synthesis and spectroscopic studies on organotin derivatives of biologically active Schiff bases

Some five- and six-coordinated di- and tri-n-butyl tin(IV) complexes of the type Bu₂SnL, Bu₂SnL₂ and Bu₃SnL (where L is the anion of a monofunctional bidentate or bifunctional tridentate Schiff base) have been synthesized and characterised on the basis of microanalyses, molecular weight determinations, IR, NMR (¹H, ¹³C, ¹¹⁹Sn) and ¹¹⁹Sn Mössbauer spectroscopy. These complexes are highly active towards bacteria.     

Structural features of some organotin(IV) complexes of semi- and thio-semicarbazones

Some five- and six-coordinated di and tri-n-butyl tin(IV) semi- and thio-semi carbazates have been synthesized. The characterization of these complexes, by IR, NMR (¹H, ¹³C, ¹¹⁹Sn), ¹¹⁹Sn), ¹¹⁹Sn Mössbauer and Mass spectroscopies along with X-ray diffraction, reveals that complexes of biionic ligands of the type Bu₂Sn L″ are five-coordinated having trigonal bipyramidal geometry. However, complexes of monoionic ligands of the type Bu₂SnL′₂ are six-coordinated in a distorted cis-octahedral geometry and Bu₃SnL′ are five-coordinated with a trigonal bipyramidal structure. X-ray structural studies on the compound Bu₂Sn(O.C₆H₄.CH:N.N.CS.NH₂), show that it crystallizes in a monoclinic lattice with a = 16.90 Å, b = 9.71 Å, c = 8.60 Å, and β = 103°45′.     

119Sn Mössbauer spectroscopy of Sn–O nanoparticles prepared by levitation-jet aerosol synthesis

Sn–O nanoparticles were prepared by levitation-jet aerosol synthesis and found to exhibit ferromagnetic behavior. X-ray powder diffraction analysis and ¹¹⁹Sn Mössbauer spectroscopy confirmed these nanoparticles consist of β-Sn, SnO and SnO₂ phases. The maximum specific magnetization was observed for nanoparticles containing the SnO/SnO₂ interface.     

A 119mSn Mössbauer study of the degradation of organotin stabilised PVC by gamma-irradiation

The technique of ^119mSn Mössbauer spectroscopy has been used to study the changes which occur in three organotin stabilisers within a PVC matrix when exposed to doses of γ-irradiation up to 20 Mrad. The stabilisers studied were dioctyltinbis(iso-octylthioglycollate) [Oct₂Sn(IOTG)₂], dibutyltinbis(iso-octylthioglycollate) [Bu₂Sn(IOTG)₂] and dibutyltinbis(iso-octylmaleate) [Bu₂Sn(IOM)₂] incorporated into the PVC at the appropriate commercial level by conventional hot milling techniques or solvent casting. Extended doses up to 20 Mrad showed that the final degradation product for all three stabilisers is SnCl₄ and that the rate of degradation depends not only upon the type of stabiliser but also upon the extent of thermo-mechanical damage suffered by the PVC during processing. Mössbauer spectra were recorded at intermediate doses in the range 0·1 to 10 Mrad and yielded complex spectra containing unresolved lines corresponding to mixtures of original stabilisers and degradation products. Intermediate degradation products are proposed and rapid conversion to SnCl₄ is observed to start at doses greater than 3 Mrad.     

Mössbauer studies on ferrocene complexes: XVI. Structure of triorganostannyl derivatives of dimethylaminomethylferrocene and N,N-dimethylbenzylamine

A series of new stannylated derivatives of dimethylaminomethylferrocene (DMAMF) and N,N-dimethylbenzylamine have been synthesised and their structures investigated by ¹H, ¹³C and ¹¹⁹Sn NMR together with ⁵⁷Fe and ¹¹⁹Sn Mössbauer spectroscopy. Polystannylated derivatives were synthesised from DMAMF and BuLi in the presence of TMED. The methylene protons of the CH₂NMe₂ group were diastereotopic for all the DMAMF derivatives synthesised. The chemical shift differences of these protons is discussed in terms of conformational changes. ¹³C and 119Sn shifts were used to establish the substitution patterns in the polystannylated derivatives. ¹³C shifts for the 2-substituted derivatives of both DMBA and DMAMF were reasonably additive, for both the free amines and the quaternary ammonium salts. The Mössbauer data show no evidence of pentacoordination in any of the derivatives.     

Triorganotin derivatives of 1,2-BIS(2′-carboxyphenylamino)-ethane and -propane,and ethylenediaminetetraacetic acid

Fifteen new complexes have been prepared of the type (R₃Sn)₂ L, where L is the dianion of 1,2-bis(2′-carboxyphenylamino)-ethane-and -propane, and ethylenediaminetetraacetic acid, and R is Me, n-Pr, n-Bu, Ph, or cyclohexyl (Cy). Characterisation by IR, ¹H NMR and ¹¹⁹Sn Mössbauer spectroscopy indicates that the ligands are bound only through oxgen. In most cases the carboxylates are bidentate and the tin five-coordinate. The Ph₃Sn and Cy₃Sn derivatives contain tetrahedral tin, with monodentate carboxylates.     

Variable temperature 119mSn Mössbauer studies of Ph3SnSCH2CH2COOSnPh3 and Bu3SnSCH2CH2COOSnBu3

Variable temperature ^119mSn Mössbauer data are presented for two organotin compounds which each contain 4- and 5-coordinate tin sites. The absorption line areas of each site have been determined and the Debye model of solids has been used to fit the experimental data. The Debye temperature associated with each site has been determined, and compared with other data.     

Effects of side-chains ofN-acetylamino acids on the structures of their triphenyltin(IV) complexes

Triphenyltin(IV) complexes ofN-acetylglycine,N-acetyl-L-leucine,N-acetyl-L-asparagine andN-acetyl-L-tyrosine were prepared by two methods and characterized by means of different spectroscopic methods (FTIR, multinuclear,¹H,¹³C and¹¹⁹Sn NMR and¹¹⁹Sn Mössbauer). The spectroscopic data indicated that theN-acetylglycine complex adopts a trigonal-bipyramidal structure in which the monodentate carboxylate and the amide-C=O group are bound to the same organotin(IV) moiety. The other three complexes are linear oligomers in which the planar Ph₃Sn(IV) is coordinated axially by a monodentate carboxylate and an amide-C=O from two different ligands. At theC-terminal end of the oligomer chain there is a tetracoordinated tin(IV) with a monodentate carboxylate as donor group.     

Synthesis, spectroscopic characterization, and in vitro fungicidal activity of some organotin(IV) complexes

Triphenyl-and tribenzyltin(IV) complexes of the ligand (sodium 5,5-diethyl barbital) have been synthesized and characterized by various spectroscopic methods. Trigonal bipyramidal geometry is assigned to all the complexes on the basis of results obtained by ¹H, ¹³C, and ¹¹⁹Sn NMR spectroscopy, IR, and ¹¹⁹mSn Mössbauer studies. Fungicidal activity of the complexes was studied using various plant pathogens via the hanging drop method. The triphenyltin(IV) complex of this ligand exhibited promising activity against all the plant pathogens at all concentrations used, while the tribenzyltin(IV) complex also showed significant fungicidal activity.     

Mössbauer studies on ferrocene complexes: XV. Structure and reactivity of trialkyl- and triaryl-stannyl ferrocenes

⁵⁷Fe and ¹¹⁹Sn Mössbauer data are reported for mono- and bis-triorganostannyl ferrocenes together with ¹¹⁹Sn NMR chemical shifts. The reactions of bis-triphenyl-stannylferrocene Fc(SnPh₃)₂ with various electrophiles have been studied. Acid cleavage occurred with both FcSn and PhSn bond fission. In contrast, mercuri-destannylation with HgCl₂ gave only Fc(HgCl)₂. Iodination gave a mixture of the mono- and bis-iodides Fc(SnPh₃)(SnPh₂I)₂ and Fc(SnPh₂I)₂ resulting from dominant PhSn cleavage. Oxidation of Fc(SnPh₃)₂ by FeCl₃ required more than one equivalent of oxidant. The ⁵⁷Fe and ¹¹⁹Sn Mössbauer spectra of the resultant ferrocinium ion was notable for the appearance of a measurable quadrupole splitting in both cases; this is discussed in terms of polar and steric effects.     

Austauschreaktionen an organostannylphosphinen: Identifizierung einer stabilen zwischenstufe

Monomeric 1 : 1 adducts of di-t-butyl(chlorodimethylstannyl)phosphine and dimethyltin dichloride are formed in solution by mixing equimolar amounts of the two components or by mixing dimethyltin dichloride and di-t-butyl(trimethylsilyl)phosphine in a 2 : 1 molar ratio. NMR, IR, Raman and ^{119 m}Sn Mössbauer data are in agreement with a symmetrical structure with two equivalent (CH₃)₂SnCl groups bridged by di-t-butylphosphine and chloro groups. The bonding and stability of the adduct are discussed.     

Synthesis of ONO-Ligated Tetrylenes Based on 2,6-bis(2-Hydroxyphenyl)pyridines: Influence of Ligand Sterics on the Structure of the Products

A series of novel tetrylenes based on three 2,6-bis(2-hydroxyphenyl)pyridines 4 a – 4 c have been obtained by the reaction of Lappert's tetrylenes E[N(SiMe₃)₂]₂ (E=Ge, Sn) with corresponding tridentate pyridine-linked phenol-based ligands. It was found that the structure of the ligand and the size of the atom of the group 14 element drastically affect the structure of the reaction product. Ligand 4 c with a bulky tert-butyl group leads to monomeric tetrylenes, while ligands with less bulky groups lead to bis-ligand derivatives of M(IV) (M=Ge, Sn) and a coordination polymer. Also, derivatives of germanium (IV) and tin (IV) were obtained by the metathesis reaction of MCl₄ (M=Ge, Sn) with lithium phenoxides. The compositions and structures of the novel compounds were established by elemental analysis and ¹H, ¹³C, ¹¹⁹Sn ( 5 – 7 ), ¹H DOSY ( 6 ) NMR spectroscopy, in the solid state by X-ray diffraction analysis (germylene 10 , stannylene 6 , Ge⁴⁺ compound 8 , Sn⁴⁺ compound 7 ) and ¹¹⁹Sn Mössbauer spectrum of tin complex 6 . All the synthesized tetrylenes are monomeric. Tetrylenes 6 and 10 were characterized by cyclic voltammetry. A study of the redox behavior of 6 , 10 by cyclic voltammetry on a glassy carbon working electrode in acetonitrile solution of 0.1 M Bu₄NPF₆ as a supporting electrolyte showed that these compounds can be both oxidized and reduced electrochemically in the accessible potential range.