We present a laser spectroscopic study of the $\tilde{\mathrm{A}}$¹${\mathrm{\Pi }}_{\mathrm{u}}$ – $\tilde{\mathrm{X}}$¹${\mathrm{\Sigma }}_{\mathrm{g}}^{+}$ transition of ¹³C mono-substituted ${\mathrm{C}}_3$ in the 378–406 nm region. The ¹³$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$ and ¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$ isotopologues are produced in a pulsed jet expansion, by DC discharging a gas mixture of $\sim$0.3% C₂H₂/Ar (with $\sim$1% ¹³C natural abundance). By using laser induced fluorescence spectroscopy, thirteen vibronic bands belonging to the $\tilde{\mathrm{A}}$¹${\mathrm{\Pi }}_{\mathrm{u}}$ – $\tilde{\mathrm{X}}$¹${\mathrm{\Sigma }}_{\mathrm{g}}^{+}$ electronic transition have been recorded for ¹³$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$ and ¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$, eleven of which have not been reported before. The transitions cover the three fundamental vibrational modes (${\nu }_1,{\nu }_2^l,{\nu }_3$). For all the vibronic bands, the full width at half maximum of spectral lines is found to be narrower than 0.023 ${\mathrm{cm}}^{-1}$, allowing to determine the transition frequencies with an absolute accuracy of $\sim$0.003 ${\mathrm{cm}}^{-1}$. Moreover, rotational analyses of the high-resolution data have yielded accurate spectroscopic constants for the upper vibronic states studied here. The 100–000, 04⁺0–000 and 12⁻0–000 bands of ¹³$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$, and the 02⁺0–000 and 04⁻0–000 bands of ¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$ are found to be less blended by spectral features of ¹²${\mathrm{C}}_3$, and thus may be used for astronomical searches of ¹³$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$ and ¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$ in the space.

我们提出了激光光谱的研究 $\widetilde{\mathrm{一种}}$^1个${\mathrm{\Pi }}_{\mathrm{ü}}$ – $\tilde{\mathrm{X}}$^1个${\mathrm{\Sigma }}_{\mathrm{G}}^{+}$¹³ C单取代的过渡${\mathrm{C}}_3$在378–406 nm区域。在¹³$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$和¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$ 直流放电的混合气体以脉冲射流膨胀的方式产生同位素分子。 $〜$0.3％C ₂ H ₂ / Ar（与$〜$1％¹³ C自然丰度）。通过使用激光诱导荧光光谱法，属于该光谱的13个振动带$\widetilde{\mathrm{一种}}$^1个${\mathrm{\Pi }}_{\mathrm{ü}}$ – $\tilde{\mathrm{X}}$^1个${\mathrm{\Sigma }}_{\mathrm{G}}^{+}$记录了^13个电子转换$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$和¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$，其中11则以前没有报道过。过渡涵盖了三种基本的振动模式（${\nu }_{\mathrm{1个}}，{\nu }_{\mathrm{2个}}^{升}，{\nu }_3$）。对于所有振动带，发现谱线的半峰全宽比0.023窄${\mathrm{厘米}}^{--\mathrm{1个}}$，允许以绝对精度确定跃迁频率 $〜$0.003 ${\mathrm{厘米}}^{--\mathrm{1个}}$。此外，对高分辨率数据的旋转分析已为此处研究的上部振动状态产生了准确的光谱常数。100–000、04 ⁺ 0–000和12 ⁻ 0–000 ^13个波段$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$，以及02 ⁺ 0–000和04 ⁻ 0–000的^12个频段${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$被发现较少的光谱特征由¹²${\mathrm{C}}_3$，因此可用于^13的天文搜索$\mathrm{C}$¹²$\mathrm{C}$¹²$\mathrm{C}$和¹²${\mathrm{C}}^{13}\mathrm{C}$¹²$\mathrm{C}$ 在空间中。