T-dependence of the vibrational dynamics of IBP/diME-β-CD in solid state: A FT-IR spectral and quantum chemical study

• Published in: Journal of molecular structure Vol. 972; no. 1; pp. 75 - 80
• Main Authors: Crupi, V., Guella, G., Majolino, D., Mancini, I., Rossi, B., Stancanelli, R., Venuti, V., Verrocchio, P., Viliani, G.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 19.05.2010
• Subjects: Binding; Computer simulation; DFT calculations; Drugs; FTIR-ATR spectroscopy; Ibuprofen; Inclusion complexes; Molecular structure; Quantum chemistry; Reflectance; Wavenumber; FTIR-ATR spectroscopy; Inclusion complexes; DFT calculations
• ISSN: 0022-2860; 1872-8014
• DOI: 10.1016/j.molstruc.2010.01.055

Solid inclusion complex of the non-steroidal anti-inflammatory drug Ibuprofen (IBP, (2-[4-(2-methylpropyl)phenyl]-propanoic acid) with (2,6-dimethyl)-β-cyclodextrin (diME-β-CD) has been investigated by Fourier transform infrared spectroscopy in attenuated total reflectance geometry (FTIR-ATR spectroscopy) and numerical simulation. The complexation-induced changes in the FTIR-ATR spectrum of IBP have been interpreted by comparison with the theoretical vibrational wavenumbers and IR intensities of dimeric structures of IBP, derived from symmetric hydrogen bonding of the two carboxylic groups, computed by using Density Functional Theory (DFT) calculations. From temperature-dependent studies, the enthalpy change Δ H associated with the binding of IBP with diME-β-CD for 1:1 stoichiometry, in solid phase, has been estimated.