Synthesis of Some Mixed Seven‐Coordinate Complexes of the Type (MI2(CO)3LL′) (M: Mo or W; L: Pyridine or Substituted Pyridines; L′: PPh3, AsPh3 or SbPh3).

Abstract The seven-coordinate bisacetonitrile complexes [MI 2 (CO) 3 (NCMe) 2 ] (M = Mo or W) react with L′ (L′ = PPh 3 , AsPh 3 or SbPh 3 ) in CH 2 Cl 2 at room temperature to give [MI 2 (CO) 3 (NCMe)L′] which when reacted in situ with L (L = pyridine or substituted pyridines) affords good yields of 28 mixed seven-coordinate complexes [MI 2 (CO) 3 LL′]. It is likely these reactions occur via successive dissociative displacements of two acetonitrile ligands.