14N quadrupole coupling in the microwave spectra of N-vinylformamide

Raphaela Kannengiesser , Wolfgang Stahl , Ha Vinh Lam Nguyen (1) , William C Bailey

1 LISA (UMR_7583) - Laboratoire Interuniversitaire des Systèmes Atmosphériques

The microwave spectra of two conformers, trans and cis, of the title compound were recorded using two molecular beam Fourier transform microwave spectrometers operating in the frequency range 2–40 GHz, and aimed at analyses of their 14N quadrupole hyperfine structures. Rotational constants, centrifugal distortion constants, and nuclear quadrupole coupling constants Xaa and Xbb-Xcc, were all determined with very high accuracy. Two fits including 176 and 117 hyperfine transitions were performed for the trans and cis conformers, respectively. Standard deviations of both fits are close to the measurement accuracy of 2 kHz. Complementary quantum chemical calculations – MP2/6-311++G(d,p) rotational constants, MP2/cc-pVTZ centrifugal distortion constants, and B3PW91/6-311+G(d,p)//MP2/6-311++G(d,p) nuclear quadrupole coupling constants – give spectroscopic parameters in excellent agreement with the experimental parameters.

Mots clés: Microwave spectroscopy; N-Vinylformamide; Nuclear quadrupole coupling constants; Quantum chemical calculations

Domaines: Chimie théorique et/ou physique

Raphaela Kannengiesser, Wolfgang Stahl, Ha Vinh Lam Nguyen, William C Bailey. 14N quadrupole coupling in the microwave spectra of N-vinylformamide. Journal of Molecular Spectroscopy, 2015, 317, pp.50-53. ⟨10.1016/j.jms.2015.09.007⟩. ⟨hal-03183154⟩