Hydrothermal syntheses, structures and properties of two 3-D organic–inorganic hybrid mixed-valent polyoxovanadates [Ni(en)2][VIV4VV2O14] and [Cu(en)2][VIV2VV3O12.5].

Two 3-D organic–inorganic hybrid mixed-valent polyoxovanadates [Ni(en) 2 ][V IV 4 V V 2 O 14 ] ( 1 ) and [Cu(en) 2 ][V IV 2 V V 3 O 12.5 ] ( 2 ) (en = ethylenediamine) have been hydrothermally synthesized and characterized by elemental analyses, IR spectra, X-ray photoelectron spectroscopy (XPS) and single-crystal X-ray diffraction. The common feature of 1 and 2 is that both exhibit the 3-D organic–inorganic hybrid framework. It should be pointed out that the 3-D hybrid architecture of 1 is constructed from planar 2-D vanadium(IV/V)–oxygen layers through [Ni(en) 2 ] 2+ bridges, whereas the 3D hybrid framework of 2 is built by wavy 2-D vanadium(IV/V)–oxygen layers via [Cu(en) 2 ] 2+ connectors. The magnetic properties of 1 have been investigated and 1 behaves as the dominant antiferromagnetic interactions within V IV centers. [ABSTRACT FROM AUTHOR]