Xantphos as cis- and trans-chelating ligand in square-planar platinum(II) complexes. Hydroformylation of styrene with platinum-xantphos-tin(II)chloride system
Platinum(II) complexes of a diphosphine ligand xantphos (4,5-bis (diphenylphosphino)-9,9-dimethyl-xanthene) have been synthesised and characterised by NMR, conductivity and catalytic investigations. In addition to the parent complex cis -PtCl2(xantphos), trans -platinum(II) complexes of square-planar geometry containing xantphos as a trans -chelating ligand can be obtained due to the large bite angle of the ligand. The platinum- xantphos -tin(II)chloride system acts as active hydroformylation catalyst in the hydroformylation of styrene resulting in high chemo- and regio-selectivities of up to 99.8% and 88%, respectively.
Pet?cz, Gy?rgy,Berente, Zoltán,Kégl, Tamás,Kollár, László