Synthesis and structural characterization of platinum and palladium complexes containing O-donor C6X2O42- ligands

The reactions between (NBu4)(2)(C6X2O4) (X = H, dihydroxybenzoquinonate; X = Cl, chloranilate) and cis-[Pt(C6F5)(2)(THF)(2)] in 1:1 molar ratio render the mononuclear complexes [NBu4](2)[Pt(C6X2O4)(C6F5)(2)] (X = H (1), C1 (2 )). If the reaction is carried out in 1:2 molar ratio the dinuclear complex es [NBu4](2)[M-2(mu-C6X2O4)(C6F5)(4)] (M = Pt, X = H (3); M = Pt, X = Cl (4 ); M = Pd, X = H (5); M = Pd, X = Cl (6)) are obtained. Complexes 3-6 can a lso be prepared by reacting C6X2O2(OH)(2) with the dinuclear complexes [NBu 4](2)[M-2(mu-C6F5)(2)(C6F5)(4)] in molar 1:1 ratio. Cyclic voltammetry stud ies on 3 indicates that these complexes can be reversibly reduced. Neverthe less, the reduction products cannot be isolated. The oxidation of the plati num complexes 3 and 4 with an excess of Cl-2 leads to the synthesis of a mo nonuclear complex of Pt(IV), (OC-6-31)[NBu4][PtCl3(C6F5)(2)(H2O)] (7). The molecular structures of 3 and 7 have been determined by single-crystal X-ra y diffraction. (C) 1998 Elsevier Science Ltd. All rights reserved.