A novel layered niobium oxychloride compound based on Nb2 pairs and Nb6 octahedral clusters: synthesis and crystal and electronic structures of Nb10Cl16O7

Stéphane Cordier; Fakhili Gulo; Thierry Roisnel; Régis Gautier; Boris le Guennic; Jean François Halet; Christiane Perrin

doi:10.1021/ic0350990

A novel layered niobium oxychloride compound based on Nb2 pairs and Nb6 octahedral clusters: synthesis and crystal and electronic structures of Nb10Cl16O7

Inorg Chem. 2003 Dec 15;42(25):8320-7. doi: 10.1021/ic0350990.

Authors

Stéphane Cordier¹, Fakhili Gulo, Thierry Roisnel, Régis Gautier, Boris le Guennic, Jean François Halet, Christiane Perrin

Affiliation

¹ Laboratoire de Chimie du Solide et Inorganique Moléculaire, UMR 6511 CNRS-Université de Rennes 1, Institut de Chimie de Rennes, Avenue du Général Leclerc, 35042 Rennes Cedex, France. stephane.cordier@univ-rennes1.fr

PMID: 14658884
DOI: 10.1021/ic0350990

Abstract

The synthesis, single crystal structure determination, and electronic structure of Nb10Cl16O7, the first Nb6 oxychloride stabilized without countercation, are reported in this work. The crystal structure is very original since it consists of layers built up from both Nb6 octahedral clusters and Nb2 pairs. The Nb6Oi6Cli6Cla6 and Nb2(mu2-Cl)2Cl4O4 units form [Nb6Cli6Oi4O(i-i)(2/2)Cl(a-a)(4/2)Cla2]infinity infinite chains and [(Nb2(mu2-Cl)2O(2/2)Cl(4/2)O2)2]infinity double chains, respectively, that are interconnected by shared oxygen and chlorine ligands leading to layers. The cohesion of the three-dimensional structure (3D) is ensured by van der Waals contacts between layers that are randomly stacked along the [011] direction. Structural correlations between Nb10Cl16O7 and related Nb6 cluster oxyhalides, as well as NbOCl2 and NbCl4 containing Nb2 pairs, are discussed. DFT results show that among the 20 valence electrons involved in the metal-metal bonding states, 14 electrons belong to the octahedral Nb6Cli6Oi6Cla6 unit whereas the 6 others (i.e., 1.5 per Nb atom) participate in the bonding in the distorted [(Nb2(mu2-Cl)2O(2/2)Cl(4/2)O2)2]infinity double chains.