FT-IR, FT-Raman Spectra and Quantum Mechanical Study of Piperidine-3-carboxylic Acid and Its Tautomers, Isomers


YURDAKUL Ş., Yasayan N. C., Badoglu S.

OPTICS AND SPECTROSCOPY, vol.116, no.6, pp.906-918, 2014 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 116 Issue: 6
  • Publication Date: 2014
  • Doi Number: 10.1134/s0030400x14060204
  • Journal Name: OPTICS AND SPECTROSCOPY
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.906-918
  • Gazi University Affiliated: Yes

Abstract

The mid-IR, far-IR, and Raman spectra of piperidine-3-carboxylic acid were measured and interpreted with support of the MP2 andB3LYP/6-311++G(d, p) calculated harmonic vibrational spectra. 10 stable piperidine-3-carboxylic acid tautomers/isomers were found after B3LYP, calculations. The experimental absorption bands of carboxylate (COO-) group show that the free piperidine-3-carboxylic acid molecule exists in zwitterionic form and the most stable tautomer ( NAT-1) can be stabilized by an intramolecular N-H center dot center dot center dot O hydrogen bond. All vibrational frequencies of NAT-1 assigned in detail with the help of total energy distribution (TED). The experimental vibrational wave numbers were compared with the calculated data.