First Detection of Vibrational Spectra of the Vinyl and Hexatriynyl Radicals
Abstract
The first vibrational spectrum of the C _2H_3 (vinyl) radical has been identified in an FTIR study of the vacuum ultraviolet (VUV) photolysis products of ethylene (C_2 H_4) and its D- and ^{13}C-substituted isotopomers and acetylene (C_2H_2) + HI trapped in Ar at 10 K. Absorptions at 900.2 and 685.4 cm^{-1} have been assigned to the nu_8(a^ {''}), out-of-plane wagging and the nu_7(a^'), in-plane asymmetric CH_2 bending - alphaCH bending modes. The assignments are supported by the isotopic data and by comparison with the results of a GVB ab initio calculation by Dupuis and Wendoloski, and an MBPT(2) ab initio calculation. A similar FTIR study of the products of the VUV photolysis of acetylene (C_2H _2) and 1,3-butadiene (C_4 H_6) trapped in solid Ar has resulted in the first identification of a vibration of the C_6H (hexatriynyl) radical at 1953.4 cm^{-1}. Various D and ^{13}C isotopomers have been observed. The complex, overlapping spectra resulting from partial ^{13}C substitution have been fitted using a force constant adjustment calculation and support the assignment of the 1953.4 cm^ {-1} absorption to a Cequiv C stretching fundamental of linear C_6 H.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1992
- Bibcode:
- 1992PhDT........62D
- Keywords:
-
- VINYL RADICAL;
- Physics: Molecular