Crystal structure of layered bis(ethylenediamine)nickel hexavanadate as a new representative of the V6O14 series

A new [Ni(NH2CH2CH2NH2)(2)](V6O14) compound has been synthesized hydrotherm ally and was found to crystallize in the monoclinic system. The single-crys tal X-ray data leads to a disordered structure, which can be decomposed int o two ordered models with different stacking of the V6O14 layers. The struc ture of the layer is the same in both models and represents a new member of the V6O14 series. All known structures from this series are constructed fr om the same chain of square pyramids (SP), which share alternatively adjace nt or opposite edges of their bases. The differences lie in the orientation of the SP chains which are joined together by sharing corners with tetrahe dra to form the layers. Combinatorial analysis of the V6O14 structures was conducted, yielding ten possible symmetry groups for the series of V6O14 la yers. The known structures belong only to the three simplest cases with the highest symmetry.