“…Binuclear molybdenum and tungsten carbonylnitrosyls bridged both by hydride and by bidentate phosphine ligands, e.g. (μ-H)(μ-Ph 2 P(CH 2 ) n PPh 2 )M 2 (CO) 7 (NO) (M = Mo, W; n = 1−5; shown below) and (μ-H)(μ-(Ph 2 PCH 2 ) 3 CMe)W 2 (CO) 7 (NO), have been prepared by nitrosylation of their anionic octacarbonyl precursors with 1 equiv of [NO][BF 4 ] in CH 2 Cl 2 at −60 °C. , Carbonyl ligand-substitution reactions of these bimetallic complexes and the related HW 2 (CO) 9 (NO) species − have been reported. The congeneric molybdenum complex, (μ-H)Mo 2 (CO) 9 (NO), is preparable in 32% yield by treatment of Na[HMo 2 (CO) 10 ] with acidic NaNO 2 , and it undergoes similar CO-substitution reactions with a variety of Lewis bases …”