PALLADIUM-THALLIUM INTERACTIONS IN DINUCLEAR COMPLEXES WITH STRUCTURAL COMPONENTS THAT PLACE THE 2 METAL CENTERS IN CLOSE PROXIMITY

Structural studies on two heterodinuclear complexes containing palladium and thallium are reported and compare to complexes containing platinum/thallium and iridium/thallium combinations. [Tl(crown-P2)Pd(CN)2](PF6) . CHCl3 contains a planar P2Pd(CN)2 unit which is capped by a thallium(I) ion that is encapsulated within the azacrown portion of the crown-P2 ligand (Ph2PCH2N{(CH2)2O(CH2)2O(CH2)2}2NCH2PPh2). The Pd(II)-Tl(I) distance is 2.897(2) angstrom and a qualitative molecular orbital interpretation of the bonding interaction between the d8 and s2 ions is given. Orange Pd(mu-O2CMe)4Tl(O2CMe) has a structure with four bridging acetates and one acetate ion that is chelated to the thallium. The Pd(II)/Tl(III) distance (2.702(1) angstrom) is shorter than that in the crown-P2 bridged Pd(II)-Tl(I) complex, but comparison between the two structures suggests that there is no metal-metal bond in the acetate bridged structure.