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Theoretical study of stepwise hydrogenated closo-alane clusters Al13H m − (m = 1–12)статья
- Авторы: Charkin O.P., Klimenko N.M., Charkin D.O.
- Журнал: Russian Journal of Inorganic Chemistry
- Том: 51
- Номер: 2
- Год издания: 2006
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 281
- Последняя страница: 291
- DOI: 10.1134/s0036023606020173
- Аннотация: The structure, energy, and vibrational characteristics of different stepwise-hydrogenated closo-alane clusters Al13H −m (m = 1–12) were calculated within the B3LYP approximation of the density functional theory using 6-31G* and 6-311+G* basis sets. For each of the m values, there is a set of several low-lying, closely spaced (within ∼0.1–0.3 eV) isomers. In the first half of the series, inner isomers (with the centered cage Al@Al12) are preferable; and in the second half, outer isomers (with the thirteenth Al atom located on the outside of the empty Al12 icosahedron and coordinated to its face) are more favorable. In some of the outer isomers, the aluminum cage is severely distorted and loses its closo form. When a hydrogen atom is attached to paramagnetic radical anions (with odd m values), the most favorable site for attack is the Al* atom located opposite the Alt-H bond and carrying most of the unpaired electron density. The resulting diamagnetic anions contain a maximum number of linear (or quasi-linear) HAlH-Alc-AlHH or HAlH…AlHH fragments in the inner and outer isomers, respectively (the trans addition rule). The energy D m (H) of successive addition of an H atom to the centered icosahedron Al −13 depends on m in a zigzag manner: the even bonds are always ∼1 eV stronger than the odd bonds. This trend is interpreted in the framework of the molecular model of the valence states of the [Al13] “superatom” with a variable valence increasing from 1 to 12 due to the unpairing of one to six electron pairs of the cage when the first, third, etc. odd H atoms are attached to it.
- Добавил в систему: Чаркин Олег Петрович