Synthesis and characterization of the trimetaphosphate molybdenum tricarbonyl anion [(P3O9)Mo(CO)3]3-[(P3O9)Mo(CO)3]3- as its tris(bis(triphenylphosphine)iminium) salt

Treatment of (CH3CN)3Mo(CO)3(CH3CN)3Mo(CO)3 with the trimetaphosphate salt [PPN]3[P3O9]·H2O([PPN]+=[Ph3PN-PPh3]+) (acetonitrile, 25°C) gave the trimetaphosphate-molybdenum complex [(P3O9)Mo(CO)3]3-[(P3O9)Mo(CO)3]3- in 91% isolated yield. [PPN]3[(P3O9)Mo(CO)3][PPN]3[(P3O9)Mo(CO)3] was also obtained in 77% isolated yield by directly treating Mo(CO)6Mo(CO)6 with [PPN]3[P3O9]·H2O[PPN]3[P3O9]·H2O in refluxing acetonitrile, presumably by generating (CH3CN)3Mo(CO)3(CH3CN)3Mo(CO)3in situ  . Reported herein is the full characterization and structural determination of [PPN]3[(P3O9)Mo(CO)3][PPN]3[(P3O9)Mo(CO)3] and comparison to synthesized and calculated [(P3O9)M(CO)3]n-[(P3O9)M(CO)3]n- (M = group 6–9) complexes.

Trimetaphosphate molybdenum tricarbonyl trianion was obtained from molybdenum hexacarbonyl upon refluxing in acetonitrile.Figure optionsDownload as PowerPoint slideHighlights
► Presented herein is the first characterized example of a molybdenum trimetaphosphate complex.
► The synthesis involves mixing a trimetaphosphate salt with molybdenum hexacarbonyl in refluxing acetonitrile.
► Experimental data from [(P3O9)Mo(CO)3]3− are compared to previous theoretical predictions.