Comparison of structures between platinum and palladium complexes of a tetrasilyldisilene

The first η2-disilene–palladium complexes were synthesized using two different reactions; the reactions of bis(phosphine)dichloropalladiums with a 1,2-dilithiotetrakis(trialkylsilyl)disilane, which was prepared by the reaction of a stable tetrakis(trialkylsilyl)disilene with lithium (Method A) and the direct reactions of the bis(phosphine)dichloropalladiums with the stable disilene (Method B). Comparison of X-ray structural parameters of the disilene–palladium complexes with those of the corresponding platinum complex has indicated that the palladium complex is a metallacycle but its π-complex character is stronger than that of the platinum complex.Key words: disilene complex, palladium, platinum, X-ray structure, metallacycle, π-complex.