Hydrogen bonding as a probe of electron density Variations: Substituted pyridines

•Relationships between theoretical charge density parameters and reported experimental O-H stretching frequency shifts [Δν(OH)exp] induced by hydrogen bonding involving substituted pyridine derivatives are investigated.•The correlations established provide insights into the variations of the electron density at the basic center of the monomeric species within the series of pyridine derivatives studied.•The Δν(OH)exp shifts correlate excellently with the rates of quaternization of substituted pyridines with methyl iodide.•The electrostatic potential at the pyridine nitrogen for the monomeric derivatives correlates quantitatively with the Δν(OH)exp shifts.