ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
A model analysis is presented of equilibrium geometries and rotational barriers in molecules of composition H2X2, with X=O, S, Se, and Te, applying exchange perturbation theory. The basis of the model is an assumed analogy with the phenomenon of "superexchange'' (indirect exchange) in solids with paramagnetic cations. A diamagnetic center in the superexchange model is formed by two spin-paired electrons in an "effective'' 1s Slater orbital determined from the valence-shell diamagnetic susceptibility of the X atom. The model is conceptually related to the so-called "through-space'' (i.e., direct) and "through-bond'' (i.e., indirect) interactions, of recent interest in organic chemistry. A survey of the literature is given concerning alternative interpretations of equilibrium geometries and barriers (cis and trans), in particular with respect to the possible influence of lone-pair orbitals. The results of the model are found to be comparable to those of large-scale ab initio calculations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.448231
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