Microwave spectrum and structure of 2-(trifluoromethyl)pyridine^†

The high resolution rotational spectrum of 2-(trifluoromethyl)pyridine in 2 20 GHz was recorded and analyzed. Spectroscopic parameters including rotational constants, nuclear quadrupole coupling constants of ¹⁴N as well as the centrifugal distortion constants were determined. The rotational spectra of five mono-substituted ¹³C and one ¹⁵N isotopologues were also measured and assigned in natural abundance. Experimental results complemented by ab initio calculations lead to an accurate determination of the skeleton structure. The values of the planar moment inertia P_cc were determined to be 44.46 uŲ for all the measured isotopologues, indicating a C_s symmetry of this molecule. The molecular electrostatic surface potential was calculated to illustrate the trifluoromethyl substitution effects on the electron distribution.