Prototype aluminum--carbon single, double, and triple bonds: Al--CH/sub 3/, Al=CH/sub 2/, and AlequivalentCH

Journal Article · Wed Oct 01 00:00:00 EDT 1980 · J. Chem. Phys.; (United States)

OSTI ID:5051832

Fox, D J; Ray, D; Rubesin, P C; Schaefer, III, H F

Nonempirical quantum mechanical methods have been used to investigate the AlCH/sub 3/, AlCH/sub 2/, and AlCH 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 a double zeta basis set: Al(11s7p/6s4p), C(9s5p/4s2p), H(4s/2s). The /sup 1/A/sub 1/ ground state of AlCH/sub 3/ has a reasonably conventional Al--C single bond of length 2.013 A, compared to 1.96 A in the known molecule Al(CH/sub 3/)/sub 3/. The CH equilibrium distance is 1.093 A and the Al--C--H angle 111.9 /sup 0/. The structures of three electronic states each of AlCH/sub 2/ and AlCH were similarly predicted. The interesting result is that the ground state of AlCH/sub 2/ does not contain an Al--C double bond, and the ground state of AlCH is not characterized by an AlequivalentC bond. The multiply bonded electronic states do exist but they lie 21 kcal (AlCH/sub 2/) and 86 kcal (AlCH) above the respective ground states. The dissociation energies of the three ground electronic states are predicted to be 68 kcal (AlCH/sub 3/), 77 kcal (AlCH/sub 2/), and 88 kcal (AlCH). 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: Department of Chemistry and Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720
• OSTI ID: 5051832
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 73:7; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ALUMINIUM
CARBON
CHEMICAL BONDS
DATA
DISSOCIATION ENERGY
ELEMENTS
ENERGY
ENERGY LEVELS
EXCITED STATES
INFORMATION
METALS
MOLECULAR STRUCTURE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANOMETALLIC COMPOUNDS
THEORETICAL DATA
VIBRATIONAL STATES