Neubauer-Guenther P, Giesen T F, Schlemmer S, Yamada K M T
I. Physikalisches Institut, Universität zu Köln, D-50937 Köln, Germany.
J Chem Phys. 2007 Jul 7;127(1):014313. doi: 10.1063/1.2749520.
High resolution infrared spectra of the nu(4) fundamental antisymmetric stretching mode and associated hot bands of the linear carbon cluster C(7) were recorded using a tunable diode laser spectrometer in the frequency range of 2135-2141 cm(-1). Spectra of the nu(4) fundamental, nu(4)+nu(11)-nu(11), nu(4)+2nu(11)-2nu(11), and nu(4)+nu(8)-nu(8), bands have been analyzed and are compared to recent experimental results and high level ab initio calculations. In particular, the presented results give experimental evidence for the rigidity of C(7) and confirm theoretical predictions of a rather regular chain molecule, similar to the cases of C(4), C(5), and C(9). For the two energetically low-lying bending modes, nu(8) and nu(11), the rotational constants differ by less than 0.2%, from the ground state value, B(0)=0.030 624 4(28) cm(-1), in good agreement with the recent calculations by Botschwina [Chem. Phys. Lett. 354, 148 (2002)]. From the hot band analysis and the [script-l]-type doubling constant q, experimental values for the band origins of the nu(8) and nu(11) fundamentals have been derived.
使用可调谐二极管激光光谱仪在2135 - 2141厘米⁻¹频率范围内记录了线性碳簇C₇的ν(4)基频反对称伸缩模式及相关热谱带的高分辨率红外光谱。对ν(4)基频、ν(4)+ν(11)-ν(11)、ν(4)+2ν(11)-2ν(11)和ν(4)+ν(8)-ν(8)谱带进行了分析，并与最近的实验结果和高水平从头算计算进行了比较。特别是，所呈现的结果为C₇的刚性提供了实验证据，并证实了类似于C₄、C₅和C₉情况的相当规则的链状分子的理论预测。对于两个能量较低的弯曲模式ν(8)和ν(11)，其转动常数与基态值B(0)=0.030 624 4(28)厘米⁻¹相差不到0.2%，这与博施维纳最近的计算结果[《化学物理快报》354, 148 (2002)]吻合良好。通过热谱带分析和[脚本-l]型加倍常数q，得出了ν(8)和ν(11)基频的谱带起源的实验值。
