ISSN:
1572-8862
Keywords:
Niobium
;
molybdenum
;
incomplete cubane
;
ab initio
;
sulfide
;
selenide
;
halide ligands
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract Ab initio calculations with effective core potentials have been performed on the trinuclear incomplete cubane-type cores in some cluster compounds with halogen as the bridging atoms. By comparison with the bonding and electronic structures of analogous chalcogenides of M3O n S 4−n 4+ and M3O n Se 4− 4+ the metal-metal bonding, metal-ligand bonding and the electronic characteristics of halogenide clusters of Nb3CI 4 3+ , M3OCl 3 5+ (M = Mo, W), Mo3OBr 3 5+ , M3Cl 4 5+ (M = Nb, Ta), and Cu3I 4 − are discussed in terms of delocalized and localized molecular orbitals. One three-centered two-electronσ bond has been found to exist among the three skeletal metals in the clusters having eight skeletal electrons. The reason why these transition-metal halides do not show the so-called quasi-aromatic (i.e. benzene-like) character is attributed to the lack of strongd − pπ bonding in the puckeredM 3(µ−X)3 six-membered rings.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01171382
Permalink
