Hydride complexes of platinum containing phosphine and halostannyl ligands have been known since 1965 [i]. Despite the important role which these compounds play in homogeneous catalysis reactions [2], no reliable data on their structure in solutions are available in the literature. Compounds obtained by the reaction between trans-[HPtCl(PPh3)=] and SnCI2 under different conditions, to which the formula of trans-[PtH(SnCl3)(PPh3)2] has been ascribed, differed in physical properties [i, 3].

One of the most important problems in preserving the environment is the identification and quantitative determination of the contaminating substances passing into it. Upwards of 1000 organic compounds are included in the list of priority contaminants of the biosphere. 1 The main organic contaminating substances of natural waters are recognised to be phenols, lignins, pesticides and petrochemicals. Investigations have been carried out by us recently with the aim of developing procedures for the qualitative and quantitative analysis of the various classes of contaminating substances, primarily hydrocarbons and phenols, using physicochemical methods such as capillary gas chromatography (CGC), gas chromatography-mass spectrometry (GCMS) and nuclear magnetic resonance spectroscopy (NMR). oceans year, 90% entering fresh water. 2

Literature data and results obtained on the mechanisms of olefin hydrogenation and isomerisation using platinum and rhodium complexes, in particular, with PtSn and RhSn bonds were analysed. The role of alkyl derivatives of platinum and rhodium in these reactions is discussed.

In acetone or ethyl acetate, cis-[PtH(SnX3)(PPh3)2] is formed at the first stage of the reaction between [PtHX(PPh3)2] and SnX2; in inert solvent the trans-isomer is the reaction product.

i. J. C. Bailar and H. Itatani, Inorg. Chem., ~, 1618 (1965). 2. G.W. Parshall, Homogeneous Catalysis. The Application and Chemistry of Catalysis by Soluble Transition Metal Complexes, Wiley, N.Y. (1980). 3~ P. G. Antonov, Yu. N. Kukushkin, L. P. Mitronina, L. N. VasilTev, and V. P. Sass~ Zh. Neorg. Khim., 24, 1008 (1979). 4o V. I. Bogdashkina, Yu. E. Zubarev, A. B. Permin, V. S. Petrosyan~ and O. A. Reutov, Izv. Akad. Nauk SSSR, Ser. Khim., 2840 (1980). 5. K.A. OstojaStarzewski, H. Ruegger, andP. S. Pregosin, Inorg. Chim. Acta, 36, L455 (1979). 6o T. Wo Dingler and K. P. Dixon, Inorg. Chem., __13, 846 (1974). P. S. Pregosin and N. Sze, Helv. Chim. Acta, 61, 1848 (1978)~ E. N. Yurchenko L. V. Fomenko, and A. D. Troitskaya, Koord. Khim., ~, 426 (1979) o D. L. Torn and R. Hoffmann, J. Am. Chem. Soc., i00, 2079 (1978). H. C. Clark and H. Kurosawa, J. Organomet. Chem., 36, 399 (!972). o