PAUL L. RASTON, CHRISTOPHER P. MORADI, Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556; JAY AGARWAL, JUSTIN. M. TURNEY, HENRY F. SCHAEFER III, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2556; GARY E. DOUBERLY, Department of Chemistry, University of Georgia, Athens, Georgia 30602-2556.
The ethyl radical has been isolated and spectroscopically characterized in 4He nanodroplets. The five fundamental CH stretch bands are observed near 3 µm and have band origins shifted < 1 cm-1 from those reported for the gas phase species., The symmetric CH2 stretching band ( 1 ) is rotationally resolved, revealing nuclear spin statistical weights predicted by G12 permutation-inversion group theory. A permanent electric dipole moment of 0.28 (2) D is obtained via the Stark spectrum of the 1 band. The four other CH stretch fundamental bands are broadened in helium droplets and lack rotational fine structure. The approximately 1-2 cm-1 line widths for these bands are attributed to the homogeneous broadening associated with solvent-mediated rovibrational relaxation dynamics. In addition to these five fundamentals, three A1' overtone/combination bands are observed and have resolved rotational substructure. These are assigned to the 2 12 , 4 + 6 , and 2 6 bands through comparisons to anharmonic frequency computations at the CCSD(T)/cc-pVTZ level of theory.