Organotin esters of dithiocarbamylacetic acids

Abstract

Twelve di- and tri-organotin derivatives of dithiocarbamylacetic acids of the formula R n Sn(O 2CCH 2S 2CNR′ 2) 4− n (R = Me, nBu, cHex, Ph; NR′ 2 = NME 2, NEt 2, N(CH 2) 4, N(CH 2CH 2) 2O; n = 3, 2) have been prepared. On the basis of IR and Mössbauer spectroscopic data, the trimethyl-, tri-n-butyl-and triphenyltin derivatives are assigned a carboxylate-bridged structure with trans-C 3SnO 2 trigonal bipyramidal geometry at tin. The diorganotin dithiocarbamylacetates also adopt a bridged structure with a trans-C 2SnO 4 octahedral geometry at tin. The triorganotin esters dissociate into four-coordinate species in solution, as revelaed by NMR ( 1H and 13C) spectral data. The tri-cyclohexyltin esters, however, are four-coordinate monomers in the solid state and in solution. Three distannoxanes, [(R″ 2SnO 2CCH 2S 2CN-Me 2)O 2] 2 (R″ 2Sn = Bu 2Sn, BuPhSn, Ph 2Sn), were obtained as adventituous products during attempts to make the diorganotin esters from the diorganotin dihalides; for these distannoxanes the spectral data are interpreted in terms of skew-trapezoidal bipyramidal coordination at the tin atoms.