Reaction of tin metal powder with triorganophosphorus dihalides: isolation and spectroscopic characterisation of [PR3X][SnX3] and cis- and trans-Sn(PR3)2X4(X = Br or I; R3= Ph3, Ph2Me or PhMe2)
Abstract
The novel reaction of some R3PX2 compounds (X = Br or I; R3= Ph3, Ph2Me or PhMe2) with unactivated coarse-grain tin metal powder has been investigated. Initially a tin(II) species results which is then further oxidised leading to the formation of both cis- and trans-Sn(PR3)2X4. The products formed have been characterised by elemental analysis, NMR, Raman and Mössbauer spectroscopy and compared to analogous complexes. The synthesis and isolation of the iodo complexes Sn(PR3)2I4 by this new synthetic route is straightforward and contrasts with difficulties using conventional techniques, viz. the reaction of Snl4 with PR3. The relative proportions of cis- and trans-SnX4(PR3)2 isomers formed from the reaction have been determined from Mössbauer spectroscopic studies and the reason for their formation is discussed.