HYDRIDE EXCHANGE PROCESSES IN THE COORDINATION SPHERE OF TRANSITION-METAL COMPLEXES - THE OSH3(BH4)(PR(3))(2) SYSTEM

The problem of intramolecular hydrogen atom exchange in the OsH3(BH4)( PR(3))(2) system is examined from both theoretical and experimental po ints of view, through ab initio MO calculations on the OsH3(BH4)(PH3)( 2) system at the MP2, MP4, and CCSD(T) computational levels and variab le-temperature H-1 NMR studies on the OsH3(BH4)(PPr3)(2) complex. Thre e different exchange processes are fully characterized from a theoreti cal point of view through location of intermediates and transition sta tes. Experimental results supporting the existence of these three diff erent exchange processes and providing definitely its intramolecular n ature are also presented.