Excited electronic states of ketene

Journal Article · Wed May 12 04:00:00 EDT 1976 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00426a001· OSTI ID:7298613

Dykstra, C E; Schaefer, III, H F

The geometries and excitation energies of the low-lying electronic states of CH/sub 2/=C=O have been investigated using a priori theoretical methods. Three basis sets of contracted Gaussian functions were employed, double zeta (DZ), double zeta plus Rydberg (DZ + R), and double zeta plus polarization (DZ + P). Vertical transitions to 18 excited electronic states were considered, with DZ excitation energies ranging from 24,000 to 137,000 cm/sup -1/ and dipole moments from -4.1 to +2.3 D. The same states were studied with the DZ + P basis and very similar predictions made. The average differences in excitation energy and dipole moment were 2200 cm/sup -1/ and 0.33 D. For several states (including /sup 3/B/sub 1/ and /sup 1/B/sub 1/) excitation energies are lowered by as much as 30,000 cm/sup -1/ using the DZ + R basis. The predicted ground state dipole moment (1.81 D) is somewhat larger than the experimental value (1.41 to 1.44 D). The predicted ground state molecular structure compares quite favorably with experiment: r(CO) = 1.168 A (1.161 +- 0.01), r(CC) = 1.311 (1.314 +- 0.01), r(CH) = 1.070 A (1.079 +- 0.002), and ..cap alpha..(HCH) = 120.1/sup 0/ (122.3 +- 0.2). For eight low-lying excited states, equilibrium geometries are predicted.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 7298613
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 98:10; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
023000 -- Petroleum-- Properties & Composition
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
DIPOLE MOMENTS
ELECTRONIC STRUCTURE
ENERGY-LEVEL TRANSITIONS
EQUILIBRIUM
EXCITATION
KETENES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS