The family of tetranuclear NbOI clusters ( = 0, 1, 2): from the molecular NbOI cluster to extended chains and layers.

Unconventional reduction reactions in the Nb-O-I system have produced a number of niobium oxyiodides containing the oxygen-centered [NbO] cluster. Crystalline NbOI and two modifications of NbOI were structurally characterized by means of single-crystal X-ray diffraction studies. The new compounds can be classified as members of the NbOI family, together with the already known NbOI.