Previous Contents Next

Ab Initio Characterization of [(H3N)BH3]2, [(H3N)AlH3]2, and [(H3N)GaH3]2

Cramer, C. J.; Gladfelter, W. L.
Inorg. Chem. 1997, 36, 5358.

The dimers of [(H3N)BH3]2, [(H3N)AlH3]2, and [(H3N)GaH3]2 are characterized as head-to-tail complexes with intermolecular H-H hydrogen bonding. In the case of [(H3N)BH3]2, that hydrogen bonding is bifurcated resulting in 4 short (N)H-H(B) distances. For both [(H3N)AlH3]2 and [(H3N)GaH3]2, there are only 2 short (N)H-H(Al/Ga) distances, although the 4-atom linkage remains far from linear. The binding energies that are calculated at the MP2 level of theory using polarized-double-zeta basis sets are -15.1, -11.8, and -10.7 kcal/mol for [(H3N)BH3]2, [(H3N)AlH3]2, and [(H3N)GaH3]2, respectively. These energies appear converged to within 1 kcal/mol with respect to larger basis sets and more complete accounting for electron correlation effects. Binding energies from density functional calculations are within 0.3 kcal/mol of the MP2 results. All-electron and effective-core-potential basis sets for gallium provide similar predictions.

To request a copy of this article, send e-mail to the Research Reports Coordinator at the Minnesota Supercomputer Institute ( Please provide a mailing address and specify that you would like UMSI report 97/125.