We herein report the preparation of several mononuclear-metaphosphate complexes using simple techniques
and mild conditions with yields ranging from 56% to 78%. Treatment of cyclo-tetrametaphosphate
([TBA]4[P4O12]·5H2O, TBA = tetra-n-butylammonium) with various metal sources including (CH3CN)3-
Mo(CO)3, (CH3CN)2Mo(CO)2(η3-C3H5)Cl, MoO2Cl2(OSMe2)2, and VOF3, leads to the clean and rapid formation
of [TBA]4[(P4O12)Mo(CO)3]·2H2O, [TBA]3[(P4O12)Mo(CO)2(η3-C3H5)], [TBA]3[(P4O12)MoO2Cl] and
[TBA]3[(P4O12)VOF2]·Et2O salts in isolated yields of 69, 56, 68, and 56% respectively. NMR spectroscopy,
NMR simulations and single crystal X-ray studies reveal that the [P4O12]4− anion behaves as a tridentate
ligand wherein one of the metaphosphate groups is not directly bound to the metal. cyclo-Trimetaphosphate-
metal complexes were prepared using a similar procedure i.e., treatment of [PPN]3[P3O9]·H2O (PPN =
bis-(triphenylphosphine)iminium) with the metal sources (CH3CN)2Mo(CO)2(η3-C3H5)Cl, MoO2Cl2(OSMe2)2,
MoOCl3, VOF3
, WOCl4
, and WO2Cl2(CH3CN)2 to produce the corresponding salts, [PPN]2[(P3O9)-
Mo(CO)2(η3-C3H5)], [PPN]2[(P3O9)MoO2Cl], [PPN]2[(P3O9)MoOCl2], [PPN]2[(P3O9)VOF2]·2CH2Cl2, and
[PPN]2[(P3O9)WO2Cl] in isolated yields of 78, 56, 75, 59, and 77% respectively. NMR spectroscopy, NMR simulations
and single-crystal X-ray studies indicate that the trianionic ligand [P3O9]3− in these complexes also has
κ3 connectivity