REACTION OF TIN METAL-POWDER WITH TRIORGANOPHOSPHORUS DIHALIDES - ISOLATION AND SPECTROSCOPIC CHARACTERIZATION OF [PR(3)X][SNX(3)] AND CIS-SN(PR(3))(2)X(4) AND TRANS-SN(PR(3))(2)X(4) (X=BR OR I R(3)=PH(3), PH(2)ME OR PHME(2))

The novel reaction of some R(3)PX(2) compounds (X = Br or I; R(3) = Ph (3), Ph(2)Me or PhMe(2)) with unactivated coarse-grain tin metal powde r has been investigated. Initially a tin(ll) species results which is then further oxidised leading to the formation of both cis- and trans- Sn(PR(3))(2)X(4). The products formed have been characterised by eleme ntal analysis. NMR, Raman and Mossbauer spectroscopy and compared to a nalogous complexes. The synthesis and isolation of the iodo complexes Sn(PR(3))(2)I-4 by this new synthetic route is straightforward and con trasts with difficulties using conventional techniques, viz. the react ion of SnI4 with PR(3). The relative proportions of cis- and trans-SnX (4)(PR(3))(2) isomers formed from the reaction have been determined fr om Mossbauer spectroscopic studies and the reason for their formation is discussed.