Semireduced bridging ligands containing N-N multiple bond coordination sites. ESR study of binuclear Group 6 metal carbonyl complexes. Inorganic Chemistry, (25)19:3442--3448, 1986. [PUMA: ESR ESR;ENDOR ESR;tetrazine VIB azobipyridine azopyridine binuclear carbonyl complex complex;ESR complex;pyridyltetrazine molybdenum]