Molecular and electronic structures of six-coordinate W complexes and polyanions containing tri-oxo groups

The molecular and electronic structures of [WO3(OL)(3)] (L: CN, H-2, H) complexes and of the [W2O9](6-) and [W4O16](8-) polyanions have been investigated using density-functional methods. Structural and bonding analyses have been performed employing various molecular-orbital and population approaches. Correlations of the trans-influence type between bonds to unshared and to high-coordinate oxygen atoms have been observed for geometrical and electronic parameters, such as W-O distances and orders. The (trans) bridging bonds have been found to be (separately) rather weak, as suggested by their (long) lengths, but the valency and orbital-interaction results have indicated that the overall bonding capacity and strength are similar for all oxygen atoms in each individual polyanion. (C) 2001 Elsevier Science Ltd. All rights reserved.