Electronic and molecular structure of 2,2'-bipyrimidine-bridged bis(organoplatinum) complexes in various oxidation states. Radical-bridged diplatinum species and the absence of a Pt(III)/Pt(II) mixed-valent intermediate. Inorganica Chimica Acta, (264)1-2:269--278, 1997. [PUMA: diplatinum;DFT platinum crystal dinuclear;electronic organoplatinum mol bridged dinuclear;electrochem bipyrimidine oxidn structure]