Convenient preparation of (eta(4)-alkadiene)dichloroplatinum(II) complexes from [PtCl(6)](2-) anions and their reduction to platinum(0) alkene complexes under phase-transfer catalysis conditions

Convenient one-pot reduction-complexation reactions of hexachloroplatinato(IV) anions to (eta(4)-alkadiene) dichloroplatinum(II) complexes (eta(4)-alkadiene = COD, DAE, DCPD, NBD) under suitable phase-transfer catalysis conditions are reported. Reduction to zerovalent platinum alkene complexes has been obtained in the presence of an excess of alkene, potassium formate and 18-crown-6 as phase-transfer catalyst (alkene = COD, NB, dba). The crystal and molecular structure of [Pt(1.03)(dba)(3)]center dot CH(2)Cl(2) has been studied by X-ray diffraction methods: it can be described as a solid solution of Pt(dba)(3) and Pt(2)(dba)(3), the mononuclear complex being largely prevailing.