Sakaizumi T, Tanaka H, Hirano K, Kuze N, Ohashi O
Faculty of Science and Technology, Sophia University, 7-1, Kioi-cho, Chiyoda-ku, Tokyo, 102-8554, Japan
J Mol Spectrosc. 1999 Mar;194(1):79-86. doi: 10.1006/jmsp.1998.7774.
trans-1-Nitrosopropene (syn form) was generated in the gas phase by pyrolysis of 1-chloro-1-methyl-2-(hydroxyimino)ethane and identified by microwave spectroscopy. The microwave spectrum of the pyrolysate was observed in the frequency range from 8.0 to 40.0 GHz. The rotational constants (MHz) were determined as A = 34 025(390), B = 2315.62(2), and C = 2198.54(2) for CH3CH&dbond;CH-NO (normal species) and A = 34 012(530), B = 2300.04(3), and C = 2182.70(2) for CH3CH&dbond;CH-15NO (15N isotopic species) in the ground vibrational state. The values of planar moment (Pcc = (Ia + Ib - Ic)/2) obtained for the normal and 15N isotopic species were found to be 1.62(10) and 1.52(13) uÅ2, respectively. These values are almost the same within the limit of errors. This suggests that the nitrogen atom lies in or is close to the ab inertial plane of the molecule and shows also that only two hydrogen atoms are located symmetrically out of the symmetry plane. The pyrolysate was determined to be trans-1-nitrosopropene by comparing the observed and calculated rotational constants, kappa (Ray's asymmetric parameter), and rs coordinates of the nitrogen atom. One vibrationally excited state was observed and assigned to the C-N torsional mode (158(50) cm-1). Interesting pyrolysates such as hydrogen cyanide and acetaldehyde were also detected during the pyrolysis of the precursor. The lifetime of trans-1-nitrosopropene is found to be ca. 5 s in the waveguide cell. Copyright 1999 Academic Press.
通过1-氯-1-甲基-2-（羟基亚氨基）乙烷的热解在气相中生成反式-1-亚硝基丙烯（顺式异构体），并通过微波光谱法进行鉴定。在8.0至40.0 GHz的频率范围内观察到热解产物的微波光谱。对于处于基振动态的CH3CH═CH-NO（正常物种），其转动常数（MHz）确定为A = 34025(390)、B = 2315.62(2)和C = 2198.54(2)；对于CH3CH═CH-15NO（15N同位素物种），其转动常数为A = 34012(530)、B = 2300.04(3)和C = 2182.70(2)。正常物种和15N同位素物种的平面矩（Pcc = (Ia + Ib - Ic)/2）值分别为1.62(10)和1.52(13) uÅ2。在误差范围内，这些值几乎相同。这表明氮原子位于分子的ab惯性平面内或靠近该平面，并且还表明只有两个氢原子对称地位于对称平面之外。通过比较观察到的和计算出的转动常数、κ（雷氏不对称参数）以及氮原子的rs坐标，确定热解产物为反式-1-亚硝基丙烯。观察到一个振动激发态，并将其归属为C-N扭转模式（158(50) cm-1）。在前体热解过程中还检测到了有趣的热解产物，如氰化氢和乙醛。发现反式-1-亚硝基丙烯在波导池中寿命约为5 s。版权所有1999年学术出版社。
