c70 Journal of Organometallic CT~emistry. zyxwvutsrqponmlkjihgfed 60 (1973) C70-i373 0 Ebevier Sequoia S-A., Lausanne - Printed in The Netherlands zyxwvutsr Preliminary communication The synthesis, structure, and reactions of some simple unsaturated a-hydro- carbylplatinum(I1) complexes C.J. CARDIN, D-J. CARDIN and M.F. LAPPERT School of Molecule Sciences, University of Sussex, Brighton zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ BIW 9QJ (Great Brirain) and K.W. MUIR Chemistry zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Deparrmenr, Univeni~ ofGlasgow, Glasgow Cl2 BQQ (Grtw zyxwvutsrqponmlkjihgfedcbaZYXWV Britain) (Received August 31st. 1973) SUMMARY Trimethyltin compounds Me3 Sn-R (R = zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPON CH=CHs , CF=CFa , or CZPh) are selective reagents for the synthesis of unsaturated hydrocarbyl derivatives such as traiu- PtCl(R)(PPhEt2), , by R/Cl exchange or oxidative addition (e.g., to Pt(PPhs)s); single crystal X-ray analyses of two such compounds (R = CH=CH2 or CqPh) show that the zyxwvutsrqponm t r am-inf luence of R has only a low sensitivity to hybridisation at carbon, with sp3 > sp 2 SPY There has been much interest in the nature of the transition metal-carbon bond with reference to unsaturated ligands, pa&cularly in platinum chemistry, and speculation on the binding in terms of the Chatt-Dewar model. X-ray crystallographic studies have ‘provided most of the experimental results. One approach to the problem is through study of the effect of hybridisation at carbon on the I&and trans-influence. In this context it is noteworthy that NMR coupling constant data on appropriate complexes have been interpreted to give an NMR Dans-influence order of zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQ C(sp3) Z Cfsp’) > C(sp' )_ We now present data on the synthesis, structure, and reactions of some simple vinyl, fluorovinyl, and acetylide derivatives of platinum(I1). A feature of the syntheses (A or B in Table 1) is the use of the selective reagents Me;SnR; in increasing order of reactivity R = CH=CH2 < CF=CFa < CsPh. For R = CH=CH2, the trans-monovinyl derivatives of platinum are obtained exclusively by R/Cl ligand exchange [eg., using cis-PtC12(PPhEta)a], (method A), in con-t to routes employing (i) (CHa=CH)e Sn, which affords very poor yields, (ii) CH2 =CHMgBr from which PtBrsP* was chiefly obtained, and (iii) CH2=CHLi. For R = CF%Fz or mph,