Synthesis, stereochemistry, and solution dynamics of heterobimetallic complexes with metals connected by dithioxamides in kappa-S,S ' kappa-N,N ' binucleation mode. The molecular structure of [2-(diphenylphosphino)pyridine-Pt-Cl- (mu-N,N '-dibenzyldithioxbisamidato-kappa-S,S '-Pt-kappa-N,N '- Pd)(eta(3)-allyl)Pd]