Reinvestigation of molybdenum(IV) coordination by flavin gives evidence for partial pteridine reduction

Research was conducted to examine the coordination of alloxazine and pterins to molybdenum(IV). The synthesis and crystal structures of MoOCL3(pteridineH) were investigated starting from Mo(IV)Cl4(acetonitrile)2 and the pteridine ligand in methanol or chloroform. Results strongly suggest that pteridine protonation is facilitated by molybdenum(IV) coordination due to partial reduction of pteridine ring through electronic delocalization from Mo to the pteridine ligand.