Bernard Mahieu

Synthesis, characterization and in vitro antitumour activity of triphenyl- and tri-n-butyltin benzoates, phenylacetates and cinnamates

Spectroscopic, structural and antitumour properties of triphenyltin and tri-n-butyltin benzoates, phenylacetates and cinnamates are compared with those of their corresponding pentafluorophenyl analogues.

Dibutyltin perfluoroalkanecarboxylates: synthesis, NMR characterization and in vitro antitumour activity

Three dibutyltin perfluoroalkanecarboxylates have been synthesized, characterized by H-1-, C-13-, F-19- and Sn-117-NMR, Mossbauer, IR and mass spectroscopy. The structure of tetra-n-butylbis(trifluoroacetato)distannoxane has been elucidated by X-ray crystallography. The in vitro antitumour activity of the three compounds against seven human tumour cell lines was found to be as high as or even higher than that for reference compounds used clinically

Organotin(IV) derivatives of 3,4-(methylenedioxy)phenylacetic acid: Synthesis, spectroscopic characterization and in vitro antitumour properties

The triphenyltin and tri-n-butyltin 3,4-(methylenedioxy)phenylacetates as well as the tetra-n-butylbis[3,4-(methylenedioxy)phenylacetato]distannoxane dimer have been synthesized and characterized by H-1, C-13, Sn-117 NMR, Sn-119m Mossbauer and mass spectroscopy. The compounds have been screened against a panel of tumour cell lines of human origin.

Di‐ and tri‐organotin derivatives of 3S,4S‐3‐[(R)‐1‐(tert‐butyl‐dimethylsilyloxy)ethyl]‐4‐[(R)‐1‐carboxyethyl]‐2‐azetidinone: synthesis, characterization and in vitro antitumour activity

Di-n-butyl-, triphenyl and tri-n-butyltin derivatives of 3S,4S-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl-4-[(R)-1-carboxyethyl]-2-azetidinone were synthesized and characterized. Their antitumour activity was screened against seven tumoural cell lines of human origin. Copyright (C) 1999 John Wiley & Sons, Ltd.

Synthesis, Characterization and In vitro Antitumour Activity of Novel Organotin Derivatives of 1,2- and 1,7-Dicarba-Closo-dodecaboranes.

Several organotin derivatives of 1,2- and 1,7-dicarba-closo-dodecaboranes were synthesized and characterized by 119Sn Mössbauer, 1H, 13C and 119Sn NMR spectroscopy. Their antitumour activities in vitro against cancerous cell lines of human origin are reported.

Organotin Diphenylmonothiophosphinates - Crystal-structure of Bis(diphenylmonothiophosphinato) Dimethyltin(iv), Me2sn(ospph2)2

Organotin(IV) diphenylmonothiophosphinates, RnSn(OSPPh2)4-n (R = Me, (n)Bu, Bz, Ph, Cy; n = 2 and 3) have been synthesized in good yields by reactions of organotin halides with ammonium diphenylmonothiophosphinate. The compounds have been characterized by infrared and NMR spectra, and two representative compounds were also studied by Sn-119m-Mossbauer spectroscopy. The structure of bis(diphenylmonothiophosphinato)dimethyltin(IV), Me2Sn(OSPPh2)2, has been determined by X-ray diffraction which shows that weak Sn ... S interactions give rise to a polymeric chain structure in which the tin atom exhibits a trigonal bipyramidal geometry. The ligand is attached primarily to tin through oxygen atoms.

Impact of thermal ageing on the tin catalyst species in room temperature vulcanised polysiloxane rubbers

Tin 2-ethylhexanoate is used as a catalyst in the synthesis of room temperature cured polysiloxane rubbers. The catalyst has the potential to influence the important load bearing and ageing properties of the rubber. In this study, the structure of the catalyst and the nature of the tin species in both fresh and thermally aged polysiloxane samples (RTV5370) have been investigated. Infra-red and 13C NMR of the catalyst confirms the presence of 2-ethyl hexanoate ligands on the tin. Mossbauer Spectroscopy of the catalyst shows that the tin exists predominantly in the tin(II) oxidation state with some residual tin(IV) impurities. The tin(IV) phase predominates in the as-synthesised rubber, representing some 67% of the total tin signal, with the remainder being unreacted tin(II) species. The tin(IV) phase in the catalyst and that in the rubber are different. Overall, our observations suggest that the catalyst has taken part in the cure reaction and has been chemically modified as a result. The isomer shift (IS) and the quadrupole splitting (QS) from Mossbauer Spectroscopy suggests that the tin (IV) phase in the rubber is most probably SnO2 (stannic oxide). Toluene extraction studies show that this phase is not extractable from the rubber network, whereas the tin(II) species is easily removed. Both high temperature and room temperature ageing increase the proportion of the tin(IV) in the rubber.

On the reaction of diorganodihydroxysilanes with (t-Bu2SnO)(3). Synthesis and characterisation of a novel stannasiloxane complex and its dissociation in solution

The complex [Ph2Si(OSnt-Bu-2)(2)Ot-Bu2Sn(OH)(2)] (2) was obtained in high yield by reaction of Ph2Si(OH)(2) with (t-Bu2SnO)(3) (1). Reaction of t-Bu2Si(OH)(2) with 1 gave [t-Bu2Si(OSnt-Bu-2)(2)O] (4a) instead. The compounds were investigated by means of NMR, IR, Mossbauer spectroscopy, and in case of 2 by X-ray analysis. In solution, 2 is in equilibrium with [Ph2Si(OSnt-Bu-2)(2)O] (2a), 1, and water. t-Bu2Sn(OH)(2) (3) was prepared by controlled hydrolysis of t-Bu2Sn(OMe)(2) and was shown to undergo condensation with formation of 1. Mossbauer studies as well as Sn-119 CP MAS NMR including side band analysis suggest 3 to exhibit a dimeric structure with pentacoordinate tin. Similar studies on 1 suggest fast rotation of the molecule in the crystal lattice.

Diorganotin Derivatives of 2,6-dihydroxymethylpyridine and of 3-(n-pyrrolidino)-1,2-propanediol - Synthesis, Characterization and Invitro Antitumor-activity

Three diorganotin(IV) derivatives of 2, 6-dihydroxymethyl-pyridine and 3-(N-pyrrolidino)-1, 2-propanediol have been synthesized and characterized by Mossbauer spectroscopy, mass spectrometry and by H-1, C-13 and Sn-119 nmr. Their activities in vitro against two human tumor cell lines, MCF-7 and WiDr, are compared to those of cis-platin and doxorubicin.

[Zur umsetzung von o-brommagnesium-benzyldiphenylphosphin mit SnCl2; isolierung einer spezies mit direkter SnII-SnIV-bindung]

Zusammenfassung The reaction of o -(diphenylphosphine)phenylbromomagnesium with tin(II) chloride leads to the formation of a tin(II)-Tin(IV) containing compound, while treatment of Cl 2 SnW(CO) 5 with o -(diphenylphosphine)phenyllithium yields a phosphino-stabilized stannylene complex. The compounds were characterized by 13 C, 31 P, 119 Sn NMR and Mossbauer spectroscopy.