| Autor: |
Smith, Alice M., Schallmoser, Günter, Thoma, Anton, Bondybey, Vladimir E. |
| Předmět: |
|
| Zdroj: |
Journal of Chemical Physics; 2/1/1993, Vol. 98 Issue 3, p1776, 10p |
| Abstrakt: |
Ultraviolet (UV) laser photolysis of dicyanoacetylene, N≡C–C≡C–C≡N, isolated in an argon matrix at 16 K produces the iso-nitrile, N≡C–C≡C–N≡C, in sufficient concentration for direct Fourier-transform-infrared measurements of all five stretching vibrational fundamentals. The assignments for ν1 (2287.1 cm-1), ν2 (2203.6 cm-1), ν3 (2044.8 cm-1), ν4 (1202.3 cm-1), and ν5 (610.1 cm-1) are supported by a normal coordinate analysis using 20 vibrational frequencies from 7 isotopomers and by ab initio results of Botschwina et al. The di-isonitrile C≡N–C≡C–N≡C is also produced in small amounts and its infrared-active asymmetric stretches assigned as ν4 (2114.9 cm-1) and ν5 (1287.5 cm-1). As isotopic vibrational frequencies for N≡C–C≡C–C≡N were measured for the first time, the disputed assignments for the three totally symmetric stretching vibrations were re-examined through a normal coordinate analysis. Laser-induced fluorescence measured by a Fourier-transform-spectrometer during photolysis reveals the 1Σg+←3Σu+ electronic transition in dicyanoacetylene at T00=25 607 cm-1 and four vibronic transitions involving two totally symmetric stretching states of the ground electronic state. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
|
