ISSN:
1572-8862
Schlagwort(e):
Trinuclear cluster
;
Mo/W mixed compounds
;
reactivities
;
ab initio
;
(d-p-d)ρ bonding
;
chalcogen ligands.
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
,
Physik
Notizen:
Abstract Ab initio calculations with relativistic effective potentials have been carried out on 12 trinuclear molybdenum/tungsten cluster aqua ions [M3X4(H2O)9]4− (M3= Mo3, W3 for X = O, S, Se, Te; M3=Mo2W, MoW2 for X = O, S). The electronic structures and bonding pictures of l-12 are discussed in terms of the delocalized and localized molecular orbitals as well as the Mulliken populations, natural populations, and Mayer bond orders. It is shown that the (d-p)ρ bonding in the puckered six-membered ring of the [M3(µ-X)3] core arises from a closed continuous ring of three mutually adjacent localized (d-p-d)ρ bonds with strong interactions. It is these three-centered two-electron (d-p-d)ρ bonds that account for the unusual physicochemical properties and reactivities of these cluster compounds. The wavelengths and the assignment of electronic spectra have been given, and the relation between the wavelength shili and the (d-p)ρ bonding is discussed, The reactivities of the ligand substitution reactions and two kinds of addition reactions as weil as some kinetic and redox properties of these compounds are briefly discussed by taking advantage of this Iocalization (d-p-d)ρ a bonding picture.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF01171195
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