Microwave, infrared, and Raman spectra, r(0) structural parameters, conformational stability and ab initio calculations of cyclohexylisocyanate

作者：Zhou Sarah Xiaohua; Ward Rachel M; Tubergen Michael J; Gurusinghe Ranil M; Durig James R^*

来源：Chemical Physics, 2013, 415: 44-55.

DOI：10.1016/j.chemphys.2012.12.013

• Xenon solutions
• Cyclohexane
• Isocyanate
• Potential energy function
• Temperature dependent infrared

The microwave spectrum of cyclohexylisocyanate, c-C6H11NCO, has been investigated from 10,000 to 21,000 MHz and 44 transitions for the more stable equatorial-trans conformer were assigned. The rotational constants of the ground vibrational state were determined: A = 3546.87(28), B = 936.12(1) and C = 839.06 (1) MHz. With these rotational constants and ab initio MP2(full)/6-311+G(d,p) predicted structural values, adjusted r(0) parameters for the equatorial-trans conformer were obtained. Variable temperature (-100 to -55 degrees C) studies of the infrared spectra (3500 to 400 cm(-1)) of cyclohexylisocyanate dissolved in liquid xenon and the infrared spectra of the gas and solid were recorded. Additionally, the Raman spectrum (3600 to 100 cm(-1)) of the liquid was investigated. Two conformers (equatorial-trans and axial-trans) were identified in the fluid states. An enthalpy difference of 397 +/- 40 cm(-1) (4.75 +/- 0.47 kJ/mol) was obtained from seven conformer pairs with the equatorial-trans form more stable. Ab initio (MP2) calculations have been carried out by using a variety of basis sets.

• 出版日期2013-3-29