We recorded the rotational spectra of N₂–ethylene sulfide (ES) and N₂–dimethyl sulfide (DMS) including the ¹⁵N₂ and ¹⁵N¹⁴N isotopomers in the frequency range of 5–25 GHz by using a Fourier transform microwave spectrometer. The b-type transitions for the ortho and para states of ¹⁴N₂–ES and ¹⁵N₂–ES and c-type transitions of ¹⁴N₂–DMS and ¹⁵N₂–DMS were observed. The ¹⁵N¹⁴N–ES and ¹⁵N¹⁴N–DMS species were found to exist in two isomeric forms: inner (¹⁴N¹⁵N–ES and ¹⁴N¹⁵N–DMS) and outer (¹⁵N¹⁴N–ES and ¹⁵N¹⁴N–DMS). Neither the −ES nor −DMS complexes showed weak accompanying spectra, which had been observed for N₂–ethylene oxide (EO). This is because the potential barriers to internal rotation of ES and DMS are higher than that of EO. The spectra were analyzed by an A-reduced asymmetric-top rotational program with less than 4 kHz standard deviation, except for the ¹⁵N¹⁴N–DMS and ¹⁴N¹⁵N–DMS complexes. Rotational, centrifugal distortion, and nuclear electric quadrupole coupling constants were determined by the spectral analysis. The V₃ potential barrier to internal rotation of the two equivalent methyl groups of DMS in the ortho and para states of the ¹⁵N₂–DMS complex was determined to be about 740 cm^–1. We performed ab initio calculations in order to complement the information on the intracomplex motions obtained from the experimental spectra.

中文翻译：

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氮分子-乙撑硫和氮分子-二甲硫配合物的傅立叶变换微波光谱

我们记录n的转动光谱₂ -亚乙基硫醚（ES）和N ₂ -二甲基硫醚（DMS），包括¹⁵ Ñ ₂和¹⁵ Ñ ^14个通过使用傅立叶变换光谱仪微波在5-25千兆赫的频率范围n同位素。的b型转变为的邻位和对状态¹⁴ Ñ ₂ -ES和^15个Ñ ₂ -ES和ç型转变的¹⁴ Ñ ₂ -dms和¹⁵ Ñ ₂ -dms观察。在¹⁵ Ñ ¹⁴N–ES和¹⁵ N ¹⁴ N–DMS物种以两种同分异构形式存在：内部（¹⁴ N ¹⁵ N–ES和¹⁴ N ¹⁵ N–DMS）和外部（¹⁵ N ¹⁴ N–ES和¹⁵ N ¹⁴ N –DMS）。-ES和-DMS配合物均未显示弱的伴随光谱，这是在N _2-环氧乙烷（EO）中观察到的。这是因为ES和DMS内部旋转的潜在障碍高于EO。光谱通过A减少的不对称顶部旋转程序进行分析，标准偏差小于4 kHz，除了¹⁵ N¹⁴ N–DMS和¹⁴ N ¹⁵ N–DMS复合物。旋转，离心畸变和核电四极耦合常数通过光谱分析确定。在¹⁵ N ₂ -DMS络合物的邻位和对位态中，DMS的两个等效甲基的内部旋转的V ₃势垒被确定为大约740 cm ^-1。我们进行了从头计算，以补充有关从实验光谱中获得的复杂内部运动的信息。