Dynamics of an amorphous pharmacologically active compound – diazepam: a QENS study combined with molecular dynamics simulations. Issue 56 (17th July 2017)

• Record Type: Journal Article
• Authors: Pajzderska, Aleksandra; Gonzalez, Miguel A.; Embs, Jan P.; Mielcarek, Jadwiga; Wąsicki, Jan W.
• Is Part Of: RSC advances. Volume 7:Issue 56(2017)
• Page Start: 35504
• Page End: 35515
• Publication Date: 2017-07-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7ra06133a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : Understanding the origin of the distribution of correlation times of methyl groups reorientation by experimental and theoretical studies. Abstract : The dynamics of methyl groups in crystalline and amorphous diazepam were investigated by a combination of molecular dynamics simulations and quasielastic neutron spectroscopy methods. The reorientation of the methyl group with a single correlation time was detected in crystalline diazepam. On the other hand, methyl group rotations in the amorphous sample cannot be represented by a single relaxation time and a distribution of correlation times approximated by a log-normal function is needed to explain both the simulation and neutron results. Additionally, MD simulations showed that the intermolecular part of the interactions due to the different environment around each methyl group is responsible for the distribution of correlation times observed experimentally.