Comparative study of NH···O and NH···S intramolecular hydrogen bonds in β-aminoacrolein, β-thioaminoacrolein and their halogenated derivatives by some usual methods

Abstract

We first use the second-order Moller–Plesset theory to optimize β-aminoacrolein, β-thioaminoacrolein and a set of their halogenated derivatives, which involve N–H···O and N–H···S hydrogen bonds. Then, four different methods, namely rotation barrier method (RBM), isodesmic reaction method (IRM), geometry corrected method (GCM) and related rotamers method, (RRM) are utilized to estimate the intramolecular hydrogen bond (IMHB) energies. The linear correlations between the estimated IMHB energies and some hydrogen bond strength descriptors such as geometrical, electron density topological and spectroscopic parameters are obtained. According to our data, RRM and RBM have the best linear correlations with all of the hydrogen bond descriptors, while GCM and IRM do not reveal suitable results. It is assumed that the performance or reliability of the estimating methods is determined based on the value of squared regression coefficients (R 2). By adding the results of the previous studies including OH···O, OH···S and NH···O hydrogen bond units to the present obtained data, the methods can be sorted according to their relative reliability as follows: RRM > RBM ≫ GCM > IRM.