Vibrational spectroscopic investigation and conformational analysis of 1-cyclohexylpiperazine

The possible stable conformers of 1-cyclohexylpiperazine (1-chpp) molecule were experimentally and theoretically studied by FT-IR and Raman spectroscopy in the region of 4000–200 cm−1. The optimized geometric structures concerning to the minimum on the potential energy surface were investigated by B3LYP hybrid density functional theory method together with 6-31G(d) basis set. Comparison between the experimental and theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for predicting vibrational wavenumbers and equatorial–equatorial (e–e) form is supposed to be the most stable form of 1-chpp molecule.