Study of the polymorphic states of chloral hydrate by 35Cl NQR relaxometry

[Display omitted] •Molecular crystals of chloral hydrate in α - and β - forms were experimentally studied using 35Cl NQR relaxometry.•The results indicate the presence of hydrogen bridging bonds between two chlorine atoms of C-Cl3 groups with hydroxyl groups.•Upon transition from the β - form of chloral hydrate to the stable α - form, the mobility of chlorine atoms increases. In this article the results of an experimental study of the molecular crystal of chloral hydrate in α - and β -forms by 35Cl NQR relaxometry method with using of inverse Laplace transformation are presented. The results indicate the presence of intramolecular hydrogen bridge bonds of two chlorine atoms of C-Cl3 groups with hydrogen of hydroxyl groups. An analysis of the spin-lattice relaxation times shows that the mobility of all chlorine atoms increases upon the transition from the unstable β - form of chloral hydrate to the stable α – form.