Two New 2D and 1D Ni(II) Coordination Polymers Bridged by Vanadium-Substituted Keggin Polyoxotungstophosphates: Hydrothermal Synthesis and Crystal Structure

Two coordination polymers based on vanadium-substituted Keggin polyoxotungstophosphates as bridging ligands, {[Ni(4,4′-bipy) 1.5 (OH)(H 2 O)] 2 [H 3 PW 10 V 2 O 40 ]}·4H 2 O (4,4′-bpy = 4,4′-bipyridine) 1 and {[Ni(dpa) 2 ][Ni(dpa)(H 2 O) 3 ] 2 [PW 9 V 3 O 40 ]}·4H 2 O (dpa = 2,2′-dipyridylamine) 2 , have been obtained by hydrothermal reactions and characterized by elemental analysis, IR, XRD, TGA and single-crystal X-ray Diffraction analysis. Compound 1 is a 2D layered structure built from 1D infinite zigzag {Ni 2 (4,4′-bipy) 3 (OH) 2 (H 2 O) 2 } n 2+ chains bridged via [H 3 PW 10 V 2 O 40 ] 2− anions. Compound 2 exhibits a one-dimensional chain-like structure constructed from [Ni(dpa) 2 ] 2+ fragments bridged via bis-supported Keggin polyoxoanions [Ni(dpa)(H 2 O) 3 ] 2 [PW 9 V 3 O 40 ] 2− . The two examples demonstrate that vanadium-substituted Keggin polyoxometalates have greater coordination capability.