Nguyen Thuy, Van Vinh, Gutlé Claudine, Stahl Wolfgang, Schwell Martin, Kleiner Isabelle, Nguyen Ha Vinh Lam
Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA), CNRS UMR 7583, Université Paris-Est Créteil, Université de Paris, Institut Pierre Simon Laplace, 61 avenue du Général de Gaulle, F-94010 Créteil, France.
Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52074 Aachen, Germany.
J Chem Phys. 2020 Apr 7;152(13):134306. doi: 10.1063/1.5142857.
The rotational spectrum of 2-methylthiazole was recorded using two pulsed molecular jet Fourier transform microwave spectrometers operating in the frequency range of 2-40 GHz. Due to the internal rotation of the methyl group, all rotational transitions were split into A and E symmetry species lines, which were analyzed using the programs XIAM and BELGI-C-hyperfine, yielding a methyl torsional barrier of 34.796 75(18) cm. This value was compared with that found in other monomethyl substituted aromatic five-membered rings. The N quadrupole coupling constants were accurately determined to be χ = 0.5166(20) MHz, χ - χ = -5.2968(50) MHz, and χ = -2.297(10) MHz by fitting 531 hyperfine components. The experimental results were supplemented by quantum chemical calculations.
使用两台在2 - 40 GHz频率范围内运行的脉冲分子束傅里叶变换微波光谱仪记录了2 - 甲基噻唑的转动光谱。由于甲基的内旋转，所有转动跃迁都分裂为A和E对称种类的谱线，使用XIAM和BELGI - C - hyperfine程序对其进行分析，得到甲基扭转势垒为34.796 75(18) cm⁻¹。将该值与在其他单甲基取代的芳香五元环中发现的值进行了比较。通过拟合531个超精细成分，准确测定出N四极耦合常数为χ = 0.5166(20) MHz，χₐ - χ = -5.2968(50) MHz，以及χ = -2.297(10) MHz。量子化学计算对实验结果进行了补充。
