Search results for "SSB"
showing 10 items of 537 documents
Organotin(IV) Complexes of Aromatic Acid Hydrazides: Preparation and Spectroscopic Studies
1999
Abstract The ability of aromatic acid hydrazides, RCONHNH, to act as bidentate chelating agents towards diorganotin(IV) dichlorides has been investigated. The structure of the complexes were deduced from IR, NMR and Mossbauer spectroscopic techniques in combination with analytical data. The R2SnCI2.L complexes have octahedral geometry where the tin atom is chelated with one ligand (via carbonyl oxygen and hydrazinic nitrogen atoms), two chlorine atoms are in equatorial positions while the R groups are in the axial positions.
Organometallic complexes with biological molecules. XI. Solid state and in vivo investigations of some diorganotin(IV)-chloramphenicol and cycloserin…
1998
Abstract Diorganotin(IV) derivatives of chloramphenicol, {=D-(-)threo-2,2-dichloro-N-[ β -hydroxy- α -(hydroxymethyl)- β -(4-nitrophenyl)ethyl]acetamide (=Hchloramph)}, and D-cycloserine, {=(R)-4-amino-3-isoxazolidone [=Hcyclos]} have been prepared. The stoichiometries of the obtained compounds were R 2 SnClantib and R 2 Snantib 2 (antib −1 =chloramph −1 , R=methyl and phenyl; antib −1 =cyclos −1 , R=methyl). The solid state configuration of the complexes was investigated by I.R. and Mossbauer spectroscopy, from which structural hypotheses were inferred. In particular, the experimental data suggested monomer structures both for R 2 Sn(IV)Clchloramph and R 2 Sn(IV)chloramph 2 , in which chlo…
Organotin(IV) complexes with tetraethyl ethylene- and propylene-diphosphonates
1995
The series of organotin halide complexes with tetraethyl ethylene- and propylene-diphosphonates R n SnX 4-n .L [n=0, X=Cl; n=1, R=Me, X=Cl, Br; n=1, R=Ph, X=Cl; n=2 R=Me, Et, Bu, X=Cl, Br; n=2, R=Ph, X=Cl; L=(EtO) 2 P(O)CH 2 CHR'P(O)(OEt) 2 , R'=H, Me] were synthesized and characterized by means of NMR and Mossbauer spectroscopy. The crystal structure of the complex of diphenyltin dichloride with propylenediphosphonate was determined. The complex consists of polymer chains with bridging bidentate ligands and an octahedral tin environment containing two types of phosphoryl fragments. All of the R 2 SnX 2 adducts have trans-R 2 SnX 4 geometries of tin coordination octahedra according to the q…
Mössbauer studies on tin(IV) and organotin(IV) diacetylbis(benzoylhydrazone) complexes
1974
Abstract The Mossbauer parameters of Ph 2 SnDB, PhClSnDB and Sn(DB) 2 were determined, where DB 2− is the dianion of the multidentate ligand diacetylbis(benzoylhydrazone). According also to data treatment with the point charge model formalism, the configurations of Ph 2 Sn IV and PhSn IV derivatives appear to be essentially octahedral, with linear CSnC and CSnCl skeletons. As to Sn(DB) 2 , it appears that the electrical charge density at the Sn IV nucleus has a cubic symmetry, which is consistent with both tetrahedral and octahedral configurations around Sn IV .
Synthesis and spectroscopic characterization of R3SnIV derivatives ofN-acetyldipeptides
1993
Triorganotin(IV) derivatives of N-acetyldipeptides R3SnAcDip; RMe, Et, n-Bu, n-Oct, Cy or Ph (HAcDipN-acetylglycylglycine and N-acetylglycylvaline; RMe, n-Bu, Cy, HAcDipN-acetylglycylalanine) were obtained by neutralization of R3SnOH and HAcDip. The complexes were studied by means of 119Sn Mossbauer, IR and 1H, 13C and 119Sn NMR spectroscopy. The CSnC bond angles have been inferred by rationalization of Mossbauer nuclear quadrupole splittings as well as from NMR coupling constants. Correlations of Mossbauer isomer shifts with partial atomic charges on tin atoms have been determined: Polymeric trigonal bipyramidal structures, with near-planar R3Sn units and axial carboxylate (unidentate) and…
The synthesis and structural characterization of some triorganotin(IV) complexes of 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}acetic acid. Crystal an…
2002
Abstract Triorganotin(IV) derivatives of 2-{[(E)-1-(2-hydroxyaryl)alkylidene]amino}acetic acid have been synthesized and characterized by 1H, 13C, 119Sn-NMR, 119Sn Mossbauer and IR spectroscopic techniques in combination with elemental analyses. The crystal structures of triphenyltin 2-{[(E)-1-(2-hydroxyphenyl)methylidene]amino}acetate and trimethyltin 2-{[(E)-1-(2-hydroxyphenyl)ethylidene]amino}acetate are reported. The X-ray structures reveal that the complexes adopt a polymeric trans-O2SnC3 trigonal bipyramidal configuration with the R groups in the equatorial positions and the axial locations occupied by a carboxylate oxygen from the ligand and the phenolic oxygen of the ligand on an ad…
Characterization of complexes formed between [Me2Sn(IV)]2+ and carboxymethylcelluloses.
2006
Complexes formed between carboxymethylcellulose (CMC) and the [Me(2)Sn(IV)]2+ cation have been prepared in the solid state and characterized by FTIR and Mossbauer spectroscopy. The complexes contained CMC with varying molar weight and degree of carboxylation, and the complexes were isolated both from acidic and from neutral solutions at varying metal-to-ligand ratios. The characteristic vibration bands of the ligands were identified from their pH-dependent FTIR spectra. In the organotin(IV) complexes obtained at pH approximately 2, the -COO- moieties were found to be coordinated in a monodentate manner, and the band characteristic of the protonated (unbound) -COO- group(s) was also identifi…
Preparation and structural characterization of Ph3Sn(IV)+ complexes with pyridinecarboxylic acids or hydroxypyridene, -pyrimidine and –quinoline.
2006
A number of [Ph3Sn(IV)](+) complexes formed with ligands containing -OH (-C=O), or -COOH group(s) and aromatic IN) donor atom have been prepared. The binding sites of the ligands were identified by FT-IR spectroscopic measurements. In the complexes containing hydroxy and carboxylate functions, the carboxylato group is coordinated to the organotin(IV) centres in monodentate or bridging bidentate manner. It was also found that in the hydroxypyridine and -pyrimidine complexes the [Ph3Sn(IV)]+ moiety in most cases reacts with the phenolic form of the ligands. The rationalisation of the experimental Sn-119 Mossbauer nuclear quadrupole splittings, vertical bar Delta(exp)vertical bar - according t…
Organozin- und organobleiderivate von N-(2,4-dinitrophenyl)glycin
1982
Abstract Organotin and organolead derivatives of N -(2,4-dinitrophenyl)glycine (HDNG), R 3 MDNG (M = Sn, Pb; R = CH 3 , C 6 H 5 ) and (C 6 H 5 ) 2 Pb(DNG) 2 , have been prepared from R 3 MOH or [(C 6 H 5 ) 2 PbO] n and HDNG, respectively. (CH 3 ) 3 PbDNG was also obtained from (CH 3 ) 3 PbBr and TlDNG. According to spectroscopic data R 3 M groups in R 3 MDNG are essentially planar and are bridged by bidentate carboxylate groups of DNG. NH does not coordinate to M. Penta-coordination is also indicated by Mossbauer data of R 3 SnDNG. Also for (C 6 H 5 ) 2 Pb(DNG) 2 a chain structure but with hexacoordination of Pb is proposed. The compounds are monomeric in solution.
Synthesis and structural investigations on R2Sn(IV)-D-aldonic acid complexes (R = methyl; butyl). Their effect on a new toxicity test organism,Liza s…
2008
Eight R2Sn(IV)-D-aldonate complexes [(R = Me, Bu; D-aldonate = D-galactonate2− (Galn), D-Gluconate2− (Glun), D-Gulonate2− (Guln), D-Ribonate2− (Ribn)], five of which are new derivatives, have been synthesized and structurally characterized both in solid and solution state by IR, 119Sn Mossbauer and 1H, 13C, 119Sn NMR spectroscopies, showing that ligands act as dianonic chelating agents. In solution phase, NMR data suggest that the bidentate chelation is attained by the O1 carboxylate and the vicinal O2 alkoxide atoms, which can be dynamically extended to a third binding site (O4) competing with O2. In Me2Sn(IV)-D-gluconate complex the occurrence of a self-association process leading to a di…