The ground state rotational spectrum of 2, 3, 6-trifluoropyridine has been investigated in the 2.0 \begin{document}$ - $\end{document} 20.0 GHz region by pulsed jet Fourier transform microwave spectroscopy. The experimental rotational constants are \begin{document}$ A $\end{document} = 3134.4479(2) MHz, \begin{document}$ B $\end{document} = 1346.79372(7) MHz, and \begin{document}$ C $\end{document} = 941.99495(6) MHz. The transitions are so intense that rotational transitions of all mono- \begin{document}$ ^{13} $\end{document} C and \begin{document}$ ^{15} $\end{document} N isotopologues are measured in natural abundance. The semi-experimental equilibrium rotational constants of the 7 isotopologues were derived by taking account of the anharmonic vibrational corrections, which allowed a semi-experimental determination of the equilibrium structure of 2, 3, 6-trifluoropyridine.

中文翻译：

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2,3,6-三氟吡啶的旋转光谱：氟化对环几何形状的影响

已经通过脉冲喷射傅立叶变换微波光谱法在20.0 GHz区域研究了2，3，6-三氟吡啶的基态旋转光谱。实验旋转常数为\ begin {document} $ A $ \ end {document} = 3134.4479（2）MHz，\ begin {document} $ B $ \ end {document} = 1346.79372（7）MHz和\ begin {document } $ C $ \ end {document} = 941.99495（6）MHz。跃迁是如此强烈，以至于测量了所有单-\ begin {document} $ ^ {13} $ \ end {document} C和\ begin {document} $ ^ {15} $ \ end {document} N个同位素异构体的旋转跃迁自然丰富。考虑到非谐振动校正，得出了7个同位素的半实验平衡旋转常数，