Detection of order–disorder transition in organic solids by using temperature resolved second harmonic generation (TR-SHG)

• Published in: Journal of molecular structure 2014-12, Vol.1078, p.61-67
• Main Authors: Clevers, S., Rougeot, C., Simon, F., Sanselme, M., Dupray, V., Coquerel, G.
• Format: Article
• Language: English
• Subjects: Chemical Sciences; Cristallography; Derivatives; Diffraction; Disorders; Dynamic disorder; Ketones; Material chemistry; Molecular structure; or physical chemistry; Order disorder; Order disorder transition; Organic chemistry; Second harmonic generation; Temperature resolved second harmonic generation; Theoretical and; X-rays
• ISSN: 0022-2860; 1872-8014; 0022-2860
• DOI: 10.1016/j.molstruc.2014.04.007

[Display omitted] •The crystallographic studies of a series of triazol ketones reveal a disorder of the tert-butyl group.•TR-SHG confirms the nature of the disorder as a dynamic disorder.•TR-SHG detects the freezing temperature of the tert-butyl motion at circa −30°C.•The lack of hysteresis effect in the TR-SHG results confirms the second-order like transition. We show the detection of an order–disorder like transition by temperature-resolved second harmonic generation (TR-SHG) in a series of triazoyl ketone (X-TAK derivatives). These compounds have the particularity to exhibit a disorder on the tert-butyl (t-Bu) group that was highlighted by single crystal X-Ray diffraction (SC-XRD). TR-SHG confirms the nature of this disorder as a dynamic disorder and allows to determine the freezing temperature of the t-Bu motion.