CHEMISTRY AT DIPLATINUM CENTERS

This chapter describes dimeric complexes containing unsupported metal–metal bonds, followed by those bridged by simple ligands, such as halides or hydrides, then a number of compounds with bridging organic fragments. The number and variety of dimeric complexes have increased tremendously, however, with the availability of several bidentate ligands of a bite size suitable to coordinate in a bridging fashion. Most notable among these is bis(dipheny1phosphino) methane (dppm), and the remarkable versatility of this ligand has prompted the development of a number of analogs of dppm. Dppm and related ligands have been used to support dimeric complexes, containing platinum in the formal oxidation states 0, I, II, III, or IV. These ligands confer substantial stability on the diplatinum system, such that substitution, oxidative addition, and reductive elimination reactions within a dimeric framework can be investigated. © 1993, Academic Press Inc.