Crystal structure of disordered diethylammonium oxo(1-hydroxyethane-1,1-diphosphonato)vanadate(IV) hydrate

Crystals of diethylammonium oxo(1-hydroxyethane-1,1 -diyhosphonato)vanadate (IV) hydrate have been synthesized, and their structure has been determined by X-ray diffraction analysis. In the crystal, three metal atoms of the di sordered anionic complex in two orientations (the occupancies are 0.67 and 0.33) are linked in pairs by the tetradentate bis(chelate)-mu (2)-bridging ligands HnL4-n with the formation of the [V3O4(HnL)(3)] cyclic trimers. As a first approximation, the coordination polyhedron of the V(1) and V(2) ato ms in both orientations can be considered a tetragonal pyramid completed to a strongly distorted octahedron by the O atom of the terminal hydroxo liga nd in the case of the V(2) atom or by the mu (3)-bridging oxo O atom for th e V(1) atom. The diethylammonium cations and crystallization water molecule s are disordered. The structural formula of the complex can be most correct ly represented as [(C2H5)(2)NH2](2)[( V4+O(mu (2)-H2L)}(3) (mu (3)-O)](0.67 )[{ V4+(OH)(mu (2)-HL)}(3) (mu (3)-O)](0.33) . 2H(2)O. (C) 2001 MAIK "Nauka /Interperiodica".