Ethylenediaminium niobium oxyfluoride.

The title compound, bis(ethylenediaminium) mu-oxo-bis[tetrafluorooxoniobium(V)], (C2H10N2)2[Nb2O3F8], is a novel organically templated niobium oxyfluoride. It consists of isolated [Nb2O3F8]4- octahedral dimers charge balanced by ethylenediaminium cations, two of which lie about inversion centres. Two NbO2F4 octahedra are fused through a common O atom to form the dimers. Characteristic short terminal Nb=O bond lengths and longer Nb-F and bridging Nb-O bond lengths are observed, which result in the out-of-centre distortion of the octahedra, a manifestation of the second-order Jahn-Teller effect. Extensive hydrogen bonding between the dimers and the organic template is exhibited.