Hydrothermal Syntheses, Crystal Structures, And Magnetic Properties of a Series of Complexes Constructed from Multinuclear Copper Clusters and Polyoxometalates

A series of complexes constructed from multinuclear copper clusters and polyoxometalates, namely, [Cu 6 (PO 4 ) 2 (H 2 O) 2 (bpy) 6 ](H 3 O) 2 [P 2 W 18 O 62 ](bpy=2,2′-bipyridine, 1), [Cu 6 (PO 4 ) 2 (H 2 O) 4 (phen) 6 ](H 2 O) 2 [P 2 W 18 O 62 ] (phen = 1,10-phenanthroline, 2 ), [Cu 2 Cl(phen) 4 ][PW 12 O 40 ] ( 3 ), [Cu 4 (HPO 4 ) 2 (H 2 O) 4 (phen) 4 ](H 3 O) 2 [PV 3 W 9 O 40 ] ( 4 ), and [Cu 4 (HPO 4 ) 2 (H 2 O) 2 (bpy) 4 ](H 2 O) 2 [PVW 11 O 40 ] ( 5 ), have been successfully synthesized in situ under hydrothermal conditions via changing the ligand, adjusting the pH value, and introducing low-valence metal (V 5+ ). Complex 1 represents the first example of 1D linear chain constructed from alternating mixed-valence hexacopper (four Cu 2+ and two Cu + ) clusters and Wells−Dawson type polyoxometalates. Complex 2 exhibits an unprecedented 2D layer network based on hexacopper phosphate and Wells−Dawson type polyoxometalates. Complex 3 constructed from dicopper coordination compounds and Keggin polyoxometalates, was obtained from the similar hydrothermal treatment of 2 at much lower pH value. Complexes 4 − 5 represent the first two examples of 1D linear chain constructed from alternating tetracopper phosphate cations and V 5+ -substituted Keggin type polyoxometalates. The magnetic properties of the complexes have been investigated between 2 and 300 K.