Neon matrix ESR investigation of <sup>1</sup><sup>2</sup>C<sup>+</sup><sub>2</sub> and <sup>1</sup><sup>3</sup>C<sup>+</sup><sub>2</sub> : Confirmation of a <sup>4</sup>Σ<sup>−</sup><sub><i>g</i></sub> ground electronic state
作者:Lon B. Knight、S. T. Cobranchi、E. Earl
DOI:10.1063/1.454346
日期:1988.6.15
The 12C+2 and 13C+2 cation radicals have been isolated in neon matrices by the photoionization of C2(g) generated by the laser vaporization of thin carbon disks. A new procedure of supporting and thermally outgassing such targets for laser vaporization ESR studies in rare gas matrices is described. The ESR results confirm the 4Σ−g ground electronic state assignment for C+2 and provide a valence orbital electronic structure characterization based on the 13C hyperfine structure (hfs). The ESR lines are extremely narrow for a high-spin powder sample and an intense off-angle or ‘‘extra’’ absorption feature exibits unusual hfs. Normally forbidden (ΔMS>1) transitions were detected at low magnetic fields. The magnetic parameters for 13C+2 in a neon matrix at 4 K are: D=3668(3) MHz; g⊥ =2.0018(5); g∥ =2.0023(5); ‖A∥‖ =99.4(8) MHz; and ‖A⊥‖ =95.2(5) MHz.