Abstract Rotational spectrum of the ground state of 2-fluro-4-picoline has been investigated by pulsed jet Fourier transform microwave spectroscopy. Besides the parent species, all the mono-substituted 13C and 15N isotopologues in natural abundance have been also measured and assigned. The rotational spectrum displays the features of the quadrupole coupling effect of the 14N nucleus with a near-free internal rotation of CH3 top. The V3 barrier (191 (60) J/mol) to the internal rotation of CH3 has been estimated from the unexpected low values of the inertial defects.

中文翻译：

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2-fluoro-4-picoline 的微波光谱和结构

摘要 利用脉冲喷射傅里叶变换微波光谱研究了2-fluro-4-picoline 基态的旋转光谱。除了亲本物种外，所有天然丰度的单取代 13C 和 15N 同位素体也已被测量和分配。旋转光谱显示了 14N 原子核与 CH3 顶部近乎自由内旋转的四极耦合效应特征。CH3 内部旋转的 V3 势​​垒 (191 (60) J/mol) 已从惯性缺陷的意外低值中估计出来。