title: Tetratungsten oxide clusters W4O(n)(-/0) (n = 10-13): structural evolution and chemical bonding.
abstract: Density functional theory (DFT) calculations are carried out to investigate the electronic and structural properties of a series of tetratungsten oxide clusters, W(4)O(n)(-/0) (n = 10-13). Generalized Koopmans' theorem is applied to predict the vertical detachment energies and simulate the photoelectron spectra (PES). A large energy gap (approximately 2.9 eV) is observed for the stoichiometric W(4)O(12) cluster, which reaches the bulk value. The calculations suggest that W(4)O(12)(-/0) have the planar eight-membered ring structures, in which each tungsten atom is tetrahedrally coordinated with two bridging O atoms and two terminal O atoms. W(4)O(10)(-/0) and W(4)O(11)(-) can be viewed as removing two and one terminal O atoms from W(4)O(12)(-/0), respectively. The W(4)O(11) neutral is an interesting species, which possesses the pentabridged structure. We show that W(4)O(11)(-) contains a localized W(3+) site, which can readily react with O(2) to form the W(4)O(13)(-) cluster, whereas the corresponding neutral W(4)O(13) can be viewed as replacing a terminal oxygen in W(4)O(12) by a peroxo O(2) unit. Molecular orbital analyses are performed to analyze the chemical bonding in the tetratungsten oxide clusters and to elucidate their electronic and structural evolution.
authors.affiliation: Department of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Wen-Jie
authors.initials: WJ
authors.lastname: Chen
authors.forename: Bo-Cun
authors.initials: BC
authors.lastname: Zhao
authors.forename: Yong-Fan
authors.initials: YF
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Huang