论文标题
1.66 $μ$ m m的Ethynyl激进，CCH
The 1.66 $μ$m Spectrum of the Ethynyl Radical, CCH
论文作者
论文摘要
频率调节的二极管激光瞬态吸收光谱已记录在接近1.66 $ $ m的波长下。观察到的频谱包括强，常规的线模式。观察到的两个主要频带起源于地面$ \ tilde {x} \，^2σ^+$状态及其第一个激动的弯曲振动水平的$^2π$对称性。上部状态为$^2σ^+$对称为6055.6 cm $^{ - 1} $和$^2π$对称性为6413.5 cm $^{ - 1} $，以前尚未观察到数据，并且数据以有效的旋转量为旋转的旋转量来分析了数据，该数据是在旋转和罚款级别上分析的。 $^2π$级别，j = 29/2 $^2σ$一个。此外，已经分配了一系列较弱的线，从第二个激发弯曲（020）（$^2σ$对称水平）中吸收到先前观察到的$^2π$对称性的状态，附近6819 cm $^{ - 1} $。这些在方便的近IR激光波长处的强吸收带将有助于监测化学系统中的CCH自由基。
Frequency-modulated diode laser transient absorption spectra of the ethynyl radical have been recorded at wavelengths close to 1.66 $μ$m. The observed spectrum includes strong, regular, line patterns. The two main bands observed originate in the ground $\tilde{X}\,^2Σ^+$ state and its first excited bending vibrational level of $^2Π$ symmetry. The upper states, of $^2Σ^+$ symmetry at 6055.6 cm$^{-1}$ and $^2Π$ symmetry at 6413.5 cm$^{-1}$, respectively, had not previously been observed and the data were analyzed in terms of an effective Hamiltonian representing their rotational and fine structure levels to derive parameters which can be used to calculate rotational levels up to J = 37/2 for the $^2Π$ level and J = 29/2 for the $^2Σ$ one. Additionally, a weaker series of lines have been assigned to absorption from the second excited bending, (020), level of $^2Σ$ symmetry, to a previously observed state of $^2Π$ symmetry near 6819 cm$^{-1}$. These strong absorption bands at convenient near-IR laser wavelengths will be useful for monitoring CCH radicals in chemical systems.
