UNSYMMETRICAL AND SYMMETRICAL DIPALLADIUM COMPLEXES WITH BRIDGING DIPHENYLSILYL LIGANDS - STRUCTURES OF (ME3P)PD(MU-SIHPH2)(2)PD(PME3)(2) AND [(ME3P)PD(MU-SIHPH2)](2) IN THE SOLID-STATE AND IN SOLUTION

Dinuclear palladium complexes with true bridging diphenylsilyl ligands , [(Me3P)Pd(mu-SiHPh2)](2) (1) and (Me3P)Pd(mu-SiHPh2)(2)Pd(PMe3)(2) ( 2), were prepared and characterized by X-ray crystallography and NMR s pectroscopy. The molecular structure of these complexes suggests an ag ostic interaction between H of mu-SiHPh2 and Pd. The symmetrical struc ture of I in solution is similar to that found in the crystals and is maintained in, the temperature range +25 to -90 degrees C. The tempera ture-dependent IH and P-31(H-1) NMR spectra of 2 show dynamic behavior of the molecule caused by exchange of the phosphine ligands. The stru cture observed at -90 degrees C in the solution is similar to the crys tallographic structure.