(621cp) Study of p-Cresol/Piperazine Complex Formation Using in Situ Raman Spectroscopy and DFT Calculation

In situ Raman spectroscopy and density functional theory (DFT) calculation were used to study the formation of the hydrogen bonding complex in p-cresol/piperazine system. Raman spectra of different molar ratio were obtained to study the band peak shift, band width broadening and band intensity nonlinear changes caused by the formation of the hydrogen bond. Using CHCl₃ as internal reference, quantitative measurements on the intensities of selected bands of p-cresol/piperazine system at different temperatures and concentrations were performed. By comparing the Raman spectra obtained from theoretical calculation the hydrogen bond formed between piperazine and p-cresol was identified as O-H…N. Reaction kinetics of p-cresol and piperazine were studied by monitoring the changing of Raman intensities of N-H stretching vibration modes with time. Reaction mechanisms were discussed, concentration and temperature dependency of the complex formation were also studied.