Reactions of Cp 2ZrH 2 with Ni(dppe)(edt) and [Pd(PPh 3)(edt)] 2. Synthesis and structure of (Cp 2Zr) 2Pd(edt) 2, a novel, ethanedithiolate stabilized palladium(O) complex

Abstract

Both Ni(dppe)(edt) ( 1) (dppe = Ph 2PCH 2CH 2PPh 2; edt = ethanedithiolate) and [Pd(PPh 3)(edt)] 2 ( 2) react with zirconocene dihydride without any evidence of CS bond cleavage. Reduction of the late transition metals to the zero oxidation state occurs together with the evolution of hydrogen. For palladium the major product of the reaction is the trinuclear complex Cp 2Zr(edt)Pd(edt)ZrCp 2 · C 6H 6 ( 3) for which the crystal structure was determined. The structure was refined to R = 0.045 ( R W = 0.032) for 2640 reflections with I > 3.0σ( I). The stereochemistry around palladium is distorted tetrahedral, and the ZrPd separations are 2.866(1) Å, suggesting bonding interactions between the metals. In reactions of Cp 2ZrH 2 with 1, spectroscopic evidence suggested that Cp 2Zr(edt)Ni(dppe) was first formed, possibly with the trinuclear nickel analogue of 3, but all attempts to recrystallize these complexes failed, and the major products isolated stemmed from ligand redistribution reactions.