Microwave Spectrum of 2-Pyridinecarbaldehyde

Abstract

Abstract The microwave spectrum of 2-pyridinecarbaldehyde has been observed in the region 8–22 GHz. The rotational constants of the ground state are A=5362.52±2.19 MHz, B=1620.07±0.03 MHz, and C=1244.42±0.03 MHz and the inertia defect is −0.075 amu·Å2. This value demonstrates that the molecule is planar in its equilibrium position. The total dipole moment is 3.56±0.07 D, the components of which are μa=3.48±0.05 D and μb=0.76±0.08 D. From these facts it is concluded that the conformation of the molecule is of the O–N s-trans form. The rotational constants of the five vibrationally-excited states have also been determined.