The 1Πu← X 1Σg+ electronic spectrum of C5 in the gas phase
作者:Tomasz Motylewski、Olga Vaizert、Thomas F. Giesen、Harold Linnartz、John P. Maier
DOI:10.1063/1.479918
日期:1999.10.8
The origin and three vibronic bands of the 1Πu←X 1Σg+ electronic transition of linear C5 have been observed in the gas phase. The carbon chain is produced in a slit nozzle employing both discharge and ablation techniques. Cavity ring down spectroscopy is used to measure the electronic transition. The origin band is found at 510.94(1) nm, shifted 29 cm−1 to the red of the value in a neon matrix. Intramolecular processes lead to broadening and irregularities in the rotational structure. The relation to astronomical observations is discussed.
Fourier-transform infrared observation of SiCn chains. I. The ν4(σ) mode of linear SiC9 in Ar at 10 K
作者:X. D. Ding、S. L. Wang、C. M. L. Rittby、W. R. M. Graham
DOI:10.1063/1.479062
日期:1999.6.15
The linear SiC9 cluster has been detected for the first time in Fourier-transform infrared spectra observed when the products from the laser evaporation of Si/C rods were trapped in Ar at ∼10 K. Comparison of C13 isotopic shift measurements with the results of density functional theory calculations (DFT) confirms the identification of the ν4(σ) mode of SiC9 at 1935.8 cm−1.
Correlation of infrared and UV-visible bands of matrix-isolated carbon clusters
作者:Jan Szczepanski、Martin Vala
DOI:10.1021/j100160a030
日期:1991.4
Carbon clusters, formed by Nd:YAG laser ablation of graphite, have been trapped in solid argon at 12 K. Using Fourier transform infrared and UV-visible spectrometers in a crossed beam configuration we have recorded the IR and UV-visible absorption spectra of the same carbon/Ar matrix and followed the growth and decay of bands in both regions as a function of matrix annealing temperature and initial preparation conditions. For the IR bands at 2164 and 1998 cm-1, previously attributed to linear C5 and nearly linear C-8 clusters, respectively, good correlations have been found with the 223- and 308-nm bands, respectively. The 2164-cm-1/223-nm correlation represents the first positive assignment for an electronic band due to C5. The similarity of the 223-nm band system with the so-called 217.5-nm interstellar "hump" has been noted and it is suggested that linear C5 clusters may be responsible for this much-discussed feature. Good correlations were also found for the 2039-cm-1/283-nm, 2039-cm-1/410-nm, and 1695-cm-1/586-nm pairs. The 2039-cm-1/410-nm bands are known to originate from C3, while the species responsible for the 1695-cm-1/586 nm pair is suggested to be a cyclic cluster of six or more carbons. A prominent UV band system at 247.1 nm has been correlated with an IR band at 2004-cm-1 and tentatively assigned to linear C-9.
Laboratory observation of the rotation-vibration spectrum of gas-phase C5
作者:N. Moazzen-Ahmadi、A.R.W. McKellar、T. Amano
DOI:10.1016/0009-2614(89)87196-9
日期:1989.4
The highest asymmetric stretching fundamental (ν3) of the gas-phase linear carbon chain C5 has been detected in the laboratory using a cooled hollow-cathode discharge in C2H2+He or C2H4+He mixtures with a tunable diode laser spectrometer. Our work was guided by recent matrix-isolation and astronomical observations of this band. We have measured a total of 59 lines with J values ranging from 0 to 72
最高不对称伸缩基本(ν 3气相直链碳链的C)5已在实验室中使用冷却空心阴极放电用C被检测到2 ħ 2分+他或C 2 H ^ 4分+他的混合物用的可调谐二极管激光光谱仪。我们的工作受到该波段最近的基质隔离和天文观测的指导。我们已经测量了59条线,其J值介于0到72之间。观察到一个小的局部扰动会影响J '= 41附近的上态能级。分析测量结果以给出频带起源以及基态和激发态旋转参数的准确值。