Rovibrational spectra of nonpolar (N2O)2 and Ar-N2O complexes in the 2v2 overtone region of N2O

Authors：Li, Xiang; Liu, Zhuang; Duan, Chuanxi^*

Source：Journal of Molecular Spectroscopy, 2021, 377: 111424.

DOI：10.1016/j.jms.2021.111424

• Rovibrational spectrum
• Ar-N2O
• Nonpolar N2O dimer
• Vibrational frequencies

Rovibrational spectra of Ar-N2O and nonpolar (N2O)(2) van der Waals complexes have been recorded from 1157.2 to 1176.7 cm(-1) in 2v(2) overtone band region of N2O monomer using an external-cavity quantum cascade laser to probe the direct absorption in a slit supersonic jet expansion. One a/b hybrid vibrational band was identified for nonpolar (N2O)(2), and one b-type vibrational band for Ar-N2O, respectively. Quantum chemical calculations of vibrational frequencies and infrared intensities of these two complexes were performed at the MP2/aug-cc-pvtz level of theory. The first vibrational band is assigned tentatively as a combination band of the intramolecular symmetric and anti-symmetric in-plane bending modes of nonpolar (N2O)(2). The second vibrational band is assigned as an overtone band of the bending mode of Ar-N2O. Precise molecular constants have been derived for these two complexes. The band-origin is located at t(0) = 1168.177584(76) cm(-1) for Ar-N2O and t(0) = 1165.218580(54) cm(-1) for nonpolar (N2O)(2), which shows a blue-shift by 0.0451 cm(-1) for Ar-N2O and a red-shift by 2.9139 cm(-1) for nonpolar (N2O)(2) compared with that of the N2O (0200)-(0000) band, respectively.