Coulombic or electrostatic: Determination of the effects of substitution on the structures of 2-, 3-, and 4-picolylamine using Fourier transform microwave spectroscopy

Abstract

In this study, the microwave spectra of 2-, 3-, and 4-picolyamine were recorded in a pulsed supersonic jet. With the aid of Natural Bond Orbital analysis, NCIplot, and Multiwfn, the structural effects of substitution were explored and then quantified by comparing semi-experimental geometries. The conformational landscape of each molecule is dominated by Van der Waals interactions between the amino group and the pyridine ring. Spectra of ²H, ¹³C, and ¹⁵N were also collected and analyzed.