Detectioñ of Vibrational Bending Mode ν8 and Overtone Bands of the Propargyl...

Zhang, X., S. P. Sander, A. Chaimowitz, G. B. Ellison, and J. F. Stanton (2010), Detectioñ of Vibrational Bending Mode ν8 and Overtone Bands of the Propargyl Radical, HCCCH2 X 2B1, J. Phys. Chem. A, 114, 12021-12027, doi:10.1021/jp105605f.

Infrared (IR) absorption spectra of matrix-isolated HCCCH2 have been measured. Propargyl radicals were generated in a supersonic pyrolysis nozzle, using a method similar to that described in a previous study (Jochnowitz, E. B.; Zhang, X.; Nimlos, M. R.; Varner, M. E.; Stanton, J. F.; Ellison, G. B. J. Phys. Chem. A 2005, 109, 3812-3821). Besides the nine vibrational modes observed in the previous study, this investigation detected the HCCCH2 X 2B1 out-of-plane bending mode (ν8) at 378.0 ((1.9) cm-1 in a cryogenic argon

˜ matrix. This is the first experimental observation of ν8 for the propargyl radical. In addition, seven overtone and combination bands have also been detected and assigned. Ab initio coupled-cluster anharmonic force field calculations were used to guide the analysis. Furthermore, ν12, the HCCCH2 in-plane bending mode, has been assigned to 333 ((10) cm-1 based on the detection of its overtone (2ν12, 667.7 ( 1.0 cm-1) and a possible combination band (ν10 + ν12, 1339.0 ( 0.8 cm-1). This is the first experimental estimation of ν12 for the propargyl radical.

PDF of Publication: 
Download from publisher's website.
Research Program: 
Atmospheric Composition Modeling and Analysis Program (ACMAP)