Facile synthesis of mononuclear early transitionmetal complexes of κ~3 cyclo-tetrametaphosphate ([P_4O_(12)]~(4-)) and cyclo-trimetaphosphate ([P_3O_9]~(3-))

摘要

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[P_4O_(12)]?5H_2O, TBA = tetra-n-butylammonium) with various metal sources including (CH_3CN)_3- Mo(CO)_3, (CH_3CN)_2Mo(CO)_2(η~3-C_3H_5)Cl, MoO_2Cl_2(OSMe_2)_2, and VOF_3, leads to the clean and rapid formation of [TBA]_4[(P_4O_(12))Mo(CO)_3]?2H_2O, [TBA]_3[(P_4O_(12))Mo(CO)_2(η~3-C_3H_5)], [TBA]_3[(P_4O_(12))MoO_2Cl] and [TBA]_3[(P_4O_(12))VOF_2]?Et_2O salts in isolated yields of 69, 56, 68, and 56% respectively. NMR spectroscopy, NMR simulations and single crystal X-ray studies reveal that the [P_4O_(12)]~(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[P_3O_9]?H_2O (PPN = bis-(triphenylphosphine)iminium) with the metal sources (CH_3CN)_2Mo(CO)_2(η~3-C_3H_5)Cl, MoO_2Cl_2(OSMe_2)_2, MoOCl_3, VOF_3, WOCl_4, and WO_2Cl_2(CH_3CN)_2 to produce the corresponding salts, [PPN]_2[(P_3O_9)- Mo(CO)_2(η~3-C_3H_5)], [PPN]_2[(P_3O_9)MoO_2Cl], [PPN]_2[(P_3O_9)MoOCl_2], [PPN]_2[(P_3O_9)VOF_2]?2CH_2Cl_2, and [PPN]_2[(P_3O_9)WO_2Cl] 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 [P_3O_9]~(3-) in these complexes also has κ~3 connectivity.