Electron Attachment and Detachment, and the Electron Affinities of C(5)F(5)N and C(5)HF(4)N
Abstract
Rate constants have been measured for electron attachment to C5F5N (297-433 K) and to 2,3,5,6-C5HF4N (303K) using a flowing-afterglow Langmuir-probe apparatus (at a He gas pressure of 133 Pa). In both cases only the parent anion was formed in the attachment process. The attachment rate constants measured at room temperature are 1.8 plus or minus 0.5 x 10(exp -7) and 7 plus or minus 3 x 10(exp -10)cu cm/s, respectively. Rate constants were also measured for thermal electron detachment from the parent anions of these molecules. For C5F5N detachment is negligible at room temperature, but increases to 2530 plus or minus 890/s at 433 K. For 2,3,5,6-C5HF4N(-), the detachment rate at 303 K was 520 plus or minus 180/s. The attachment/detachment equilibrium yielded experimental electron affinities EA(C5F5N) = 0.70 plus or minus 0.05 eV and EA(2,3,5,6-C5HF4N) = 0.40 plus or minus 0.08 eV. Electronic structure calculations were carried out for these molecules and related C5HxFs5-xN using density-functional theory and the G3(MP2)//B3LYP compound method. The EAs are found to decrease by 0.25 eV, on average, with each F substitution by H. The calculated EAs are in good agreement with the present experimental results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 19, 2005
- Accession Number
- ADA442833
Entities
People
- A. A. Viggiano
- Donna M. Kerr
- Jane M. Van Doren
- Thomas M Miller
Organizations
- College of the Holy Cross