Three-component complex of piperidine-ethanol, p-hydroxybenzoic acid and water studied by X-ray, Raman, FTIR and DFT.

A novel and unique crystalline three-component complex was formed of 2-(1-piperidine)ethanol, p -hydroxybenzoic acid and water at the ratio 1:1:1. Its structure has been determined by single-crystal X-ray diffraction. This is an example of a hydrogen-bonded interaction between amino alcohol and benzoic acid molecules. Water acts as a bridge between molecules. The molecules are linked through medium-strong OH⋯O hydrogen bonds from 2.665(6) to 2.813(6) Å and NH⋯O one 2.744(5) Å in length. The molecular structure of 2-(1-piperidinium)ethanol p -hydroxybenzoate hydrate has been characterized by FTIR and Raman spectra and optimized at the B3LYP/6−311++G(d,p) level of theory. The potential energy distributions (PED) have been used to assign the vibrational spectra. Charge delocalization was analyzed using the natural bond orbital (NBO) methods. [ABSTRACT FROM AUTHOR]