THE PROTOTYPE ALUMINUM - CARBON SINGLE, DOUBLE, AND TRIPLE BONDS: Al - CH3, Al = CH2, AND Al. = CH

Journal Article · Sun Jun 01 04:00:00 EDT 1980 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.440519· OSTI ID:1022084

Fox, Douglas J; Ray, Douglas; Rubesin, Philip C; Schaefer, III, Henry F

Nonempirical quantum mechanical methods have been used to investigate the A{ell}CH{sub 3}, A{ell}CH{sub 2}, and A{ell}CH molecules, which may be considered to represent the simplest aluminum-carbon single, double, and triple bonds. Equilibrium geometries and vibrational frequencies were determined at the self-consistent-field level of theory using double zeta basis set: A{ell}(11s7p/6s4p), C(9s5p/4s2p), H(4s/2s). The {sup 1}A{sub 1} ground state of A{ell}CH{sub 3} has a reasonably conventional A{ell}-C single bond of length 2.013 {angstrom}, compared to 1.96 {angstrom} in the known molecule A{ell}(CH{sub 3}){sub 3}. The CH equilibrium distance is 1.093 {angstrom} and the A{ell}-C-H angle 111.9{sup o}. The structures of three electron states each of A{ell}CH{sub 2} and A{ell}CH were similarly predicted, The interesting result is that the ground state of A{ell}CH{sub 2} does not contain an A{ell}-C double bond, and the ground state of A{ell}CH is not characterized by an A{ell}{triple_bond}C bond. The multiply-bonded electronic states do exist but they lie 21 kcal (A{ell}CH{sub 2}) and 86 kcal (A{ell}CH) above the respective ground states. The dissociation energies of the three ground electronic states are predicted to be 68 kcal (A{ell}CH{sub 3}), 77 kcal (A{ell}CH{sub 2}), and 88 kcal (A{ell}CH), Vibrational frequencies are also predicted for the three molecules, and their electronic structures are discussed with reference to Mulliken populations and dipole moments.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Materials Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 1022084
• Report Number(s): LBL-10871
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 7 Vol. 73; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ALUMINIUM
CARBON
DIPOLE MOMENTS
DISSOCIATION
DOUBLE BONDS
ELECTRONIC STRUCTURE
ELECTRONS
GROUND STATES