Main Group Metal Chemistry
We have completed Hartree-Fock ab initio electronic structure calculations on the series of compounds Ph2MMPh2n, where M = B or Al, and n = 0, 1-, or 2-. The results show that the added one and two electrons upon reduction of the neutral compounds go into the M-M π bond, as expected. The canting of the rings in D2 symmetry is related to the degree of steric repulsion in the compounds. There is no evidence for preferential population of an Al-Al σ* orbital in the dianion of the aluminum compound, and hence we have no ready explanation as to why this ion has so far proved impossible to detect experimentally. The charge distribution in the compounds is examined with Natural Population Analysis.
Hamilton, Edward L.; Pruis, Justin G.; DeKock, Roger L.; and Jalkanen, Karl J., "A computational study of M-M multiple bonding in Ph2MMPh2n-, where M = B or Al, and n = 0, 1, or 2" (1998). University Faculty Publications and Creative Works. 492.