Two new polyoxometalate tri-supported transition metal complexes constructed from bi-capped Keggin molybdenum-vanadium clusters and copper complex fragments

Two new molybdenum-vanadium polyoxometalate tri-supported transition metal complexes [Cu(2,2′-bipy)] [Cu(2,2′-bipy)2]2[PMo8V6O42]·nH2O (n = 1.5 (1) and n = 2 (2); 2,2′-bipy = 2,2′-bipyridine) have been hydrothermally synthesized and characterized by elemental analyses, IR, XPS and single-crystal X-ray diffraction analyses. Both compound 1 and compound 2 contain molybdenum-vanadium polyoxometalates, each of which support one [Cu(2,2′-bipy)]2+ cation and two [Cu(2,2′-bipy)2]2+ cations, respectively. The difference between compound 1 and compound 2 is that the polyoxoanion of 1 is a bi-capped α-Keggin cluster and that of 2 is a bi-capped pseudo-Keggin one. Studies of magnetic properties indicated the presence of ferromagnetic behaviors for compounds 1 and 2.