Carbanion spectroscopy: CH/sub 2/CN/sup -/

Journal Article · Wed Sep 30 04:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00254a018· OSTI ID:6091447

Moran, S; Ellis, Jr, H B; DeFrees, D J; McLean, A D; Ellison, G B

The authors have measured the photoelectron spectra of CH/sub 2/CN/sup -/ and CD/sub 2/CN/sup -/ and report the following electron affinities: EA(CH/sub 2/CN) = 1.543 +/- 0.014 eV and EA(CD/sub 2/CN) = 1.538 +/- 0.012 eV. From an analysis of the peak splittings and intensities, they extract potential-energy curves for the umbrella mode of the CH/sub 2/CN/sup -/ negative ion and the CH/sub 2/CN radical. The radical is found to be a planar, C/sub 2v/ species. The structure of the cyanomethide ion is almost described as CH/sub 2/=C=N/sup -/, but the hydrogens are bent slightly out of the molecular plane. A Franck-Condon analysis leads to a value of the out-of-plane deformation angle as 30 +/- 5/sup 0/ with a very small inversion barrier of 100 +/- 50 cm/sup -1/. Their structural conclusions are reinforced by a series of ab initio Hartree-Fock and Moeller-Plesset perturbation calculations on both the cyanomethyl radical and cyanomethide ion. Using the gas-phase acidity of CH/sub 3/CN, they obtain the following bond-dissociation energy for acetonitrile: DH..pi../sub 298/ (H-CH/sub 2/CN) = 94.2 +/- 2.0 kcal/mol.

• Research Organization: Univ. of Colorado, Boulder
• DOE Contract Number: AC02-80ER10722
• OSTI ID: 6091447
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:20; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
ANIONS
CARBANIONS
CHARGED PARTICLES
DATA
DEUTERIUM COMPOUNDS
ELECTRON SPECTROSCOPY
ENERGY LEVELS
ENERGY RANGE
EV RANGE
EV RANGE 01-10
EXCITED STATES
EXPERIMENTAL DATA
HARTREE-FOCK METHOD
HYDROGEN COMPOUNDS
INFORMATION
IONS
LASERS
MOLECULAR STRUCTURE
NITROGEN COMPOUNDS
NORMAL-MODE ANALYSIS
NUMERICAL DATA
PERTURBATION THEORY
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
SPECTROSCOPY
THERMODYNAMIC PROPERTIES
VIBRATIONAL STATES