Coordination chemistry of reduced nitrogen heterocycles. Dinuclear pentacarbonyl complexes of molybdenum and tungsten with paramagnetic bridging ligands. Chemische Berichte, (115)3:910--918, 1982. [PUMA: binuclear bipyridine carbonyl complex complex;carbonyl complex;molybdenum nitrogen tungsten complex;pyrazine complex;quinoxaline complex;tungsten heterocycle heterocycle;dipyridylethene heterocycle;phenazine molybdenum]