. Metals in organic syntheses. VII. The isolation of trans-[PtCl(COPr)(PPh3)2] (I) and trans-[Pt(snCl3)(COPr)(PPh3)2], active intermediates in the hydroformylation of propene catalyzed by adichlorobis(triphenylphosphine)platinum-tin(II) chloride precursor. The crystal and molecular structure of complex I and acomparison with its palladium analog

trans-[(PrCO)PtCl(PPh3)2] (I) was isolated in good yield from the mixts. obtained by treating a mixt. of propene, cis-\ud [(Ph3P)2PtCl2] and SnCl2.H2O with CO in the presence or absence of H in an alc. in which no significant\ud hydroformylation or hydroxycarboalkylation actually occurs. The cis-[(Ph3P)2PtCl2]-SnCl2.2H2O system is highly active\ud in the catalytic hydroformylation of MeCOCH2CHMe2, and 33% trans-[(PrCO)Pt(SnCl3)(PPh3)2] (II) was isolated from\ud reaction mixts. in this medium. The presence of a Pt-Sn bond in a complex of type II plays a key role in promoting the\ud formation of the aldehyde from the acyl deriv., but it is not necessary for the formation of intermediate I, since this can be\ud isolated in good yield even in the absence of the Sn compd. The higher regioselectivity obsd. using intermediate I or II,\ud compared with that with the precursor was discussed in terms of steric effects of the ligands competing for coordination\ud to the Pt atom. The catalytic properties of I were also compared with those of its Pd analog, which catalyzes only the\ud hydrocarbalkoxylation, but does this even in the absence of SnCl2. The crystal and mol. structures of the title complex I\ud and its Pd analog were detd. from 3-dimensional, x-ray diffractometer data. Both complexes are isostructural and\ud crystallize in the monoclinic space group P21/n. The structures have approx. square-planar geometry and the\ud dimensions are not unusual