Complex and mixture of β-cyclodextrin with diazepam characterised by 1H NMR and atom–atom potential methods

• Published in: Carbohydrate research Vol. 398; pp. 56 - 62
• Main Authors: Pajzderska, A., Mielcarek, J., Wąsicki, J.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 29.10.2014
• Subjects: Atom–atom potential method; beta-Cyclodextrins - chemistry; Carbohydrate Conformation; Cyclodextrin; Diazepam; Diazepam - chemistry; Inclusion compounds; Models, Molecular; Nuclear magnetic resonance; Proton Magnetic Resonance Spectroscopy; Spin–spin relaxation time; Temperature; Cyclodextrin; Spin–spin relaxation time; Nuclear magnetic resonance; Atom–atom potential method; Inclusion compounds; Diazepam
• ISSN: 0008-6215; 1873-426X
• DOI: 10.1016/j.carres.2014.07.025

•Combined use of solid-state 1H NMR spectroscopy and atom–atom potential methods.•The magnetisation recovery indicated a formation of diazepam–cyclodextrin complex.•Activation energy for motion of CH3 in diazepam did not change in inclusion complex.•The phenyl ring of diazepam is located inside the β-cyclodextrin cavity. Inclusion complex of β-cyclodextrin with diazepam and a physical mixture of these components were studied by solid-state 1H NMR. The activation barrier for reorientation of the methyl group in the diazepam molecule was found not changed by complex formation with β-cyclodextrin. The complex formation resulted in a decrease in the number of water molecules and affected the relaxation time of β-cyclodextrin. By the atom–atom potential method the most probable configuration of the diazepam molecule inside β-cyclodextrin cavity was proposed.