FT-IR and NMR investigation of 1-phenylpiperazine: A combined experimental and theoretical study

FT-IR and 1H, 13C, DEPT, COSY, NOESY, HETCOR, INADEQUATE NMR spectra of 1-phenylpiperazine (pp) have been reported for the first time except for its 1H NMR spectrum. The vibrational frequencies and 1H, 13C NMR chemical shifts of pp (C10H14N2) have been calculated by means of the Hartree–Fock (HF) and Becke–Lee–Yang–Parr (BLYP) or Becke-3-Lee–Yang–Parr (B3LYP) density functional methods with 6-31G(d) and 6-31G(d,p) basis sets, respectively. Comparison between the experimental and the theoretical results indicates that density functional B3LYP method is superior to the scaled HF and BLYP approach for predicting vibrational frequencies and NMR properties.