The crystal structure and the disorder behaviour of NO[NbCl6]

NO[NbCl 6 ] crystallizes in the noncentrosymmetric space group P2 1 2 1 2 1 with a = 6.630(1), b = 6.746(1), c = 39.23(1) A at 150 K and Z = 8; i.e. there are two formula units in the asymmetric unit. X-ray data have been recorded by means of an imaging plate system. The interaction between the nitrosonium cations and the hexachloridoniobate anions polarizes the latter such that the niobium atoms are displaced from the centre of their chlorine polyhedra by 0.17 and 0.16 A, respectively. The NO + ions develop disorder, in both cases with preference for one out of two possible orientations.