The SiCF free radical has been spectroscopically identified for the first time. The radical was produced in an electric discharge jet using CF₃Si(CH₃)₃ or CF₃SiH₃ vapor in high pressure argon as the precursor. The laser-induced fluorescence spectrum of the $Ã{}^2\sum ^{+}-\tilde{X}{}^2\prod$ band system in the 610 − 550 nm region was recorded and the ${}^2\prod _{3/2}$ spin component of the 0—0 band was studied at high resolution. Rotational analysis gave the B values for the combining states, and by fixing the CF bond lengths at ab initio values we obtained ${\text{r}}^{″}\left(\text{Si–C}\right)=1\text{.}692\left(1\right)\text{Å}$ and ${\text{r}}^{\prime }\left(\text{Si–C}\right)=1\text{.}594\left(\text{1}\right)\text{Å.}$ The bond lengths correspond to a silicon-carbon double bond in the ground state and an unusual Si−C triple bond in the excited state. Single vibronic level emission spectra yielded the ground state bending and stretching energy levels. These were fitted to a Renner-Teller model that included spin-orbit and limited vibrational anharmonicity effects.

中文翻译：

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激光诱导的SiCF自由基荧光检测

SiCF自由基已首次通过光谱鉴定。在放电喷嘴中使用CF ₃ Si（CH ₃）₃或CF ₃ SiH ₃蒸气在高压氩气中作为前体产生自由基。激光诱导的荧光光谱$\mathrm{一个}{}^{\mathrm{2个}}\sum ^{+}-\tilde{X}{}^{\mathrm{2个}}\prod$ 记录610-550 nm区域的能带系统， ${}^{\mathrm{2个}}\prod _{3/\mathrm{2个}}$在高分辨率下研究了0-0波段的自旋分量。旋转分析给出了结合态的B值，并且通过将CF键长度固定为从头算起的值，我们获得了${\text{[R}}^{\text{'}\text{'}}\left(\text{硅碳}\right)=\mathrm{1个}\text{。}692\left(\mathrm{1个}\right)\text{一个}$ 和 ${\text{[R}}^{\prime }\left(\text{硅碳}\right)=\mathrm{1个}\text{。}594（\text{1个}）\text{一个。}$键长对应于基态的硅碳双键和激发态的不寻常的Si-C三键。单个电子振动能级发射光谱产生了基态弯曲和拉伸能级。将它们拟合到一个Renner-Teller模型，该模型包括自旋轨道和有限的振动非谐效应。