Triclinic polymorphs of ethyl-6-methyl-4-(3-nitrophenyl)-2-thioxo-1,2,3,4-tetrahydropyrimidine- 5-carboxylate: Study of intermolecular interactions from crystal structure and Hirshfeld surface analysis

International Conference on Applied Crystallography

October 17-19, 2016 Houston, USA

Mukesh M Jotani

Bhavan��?s Sheth R. A. College Science, India

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

The important pharmacological properties of dihydropyrimidines are the motivations for the extensive research in this class of compunds. As three dimensional structure and the crystal packnig interactions are pre-requisite for the bilogical action of a molecule, the attempts have been made to study the crystal packing interactions in the structures of two triclinic polymorphs of title tetrahydropyrimidine molecule through the crystal structure and Hirshfeld surface analysis.The polymorphs I and II of title molecule crystallize into same triclinic crystal system, but in different crystallographic environments with Z = 2 and Z = 4 respectively. The conformational flexibility due to the rotation of ester group and ary ring in the structure has resulted different conformations of the tetrahydropyrimidine ring in I and II.The intermolecular N-H...O, N-H...S, C-H...O and Ï�?-Ï�? stacking interactions have their influence on the the crystal packing of polymorph I, whereas in polymorph II, the interactions are of intra and inter molecular N-H...S and intermolecular C-H...O type. The Hirshfeld surface analysis for both the polymorphs were carried out using a computer program Crystal Explorer. The intermolecular interactions can be easily visualized from the Hirshfeld surfaces mapped over dnorm, de, curvedness, shape-index and electrostatic potential. The electrostatic potentials were calculated using TONTO integrated with Crystal Explorer. Further, the electrostatic potentials were mapped on Hirshfeld surfaces using STO-3G basis set at Hartree-Fock theory over a range from �?± 0.15 au. The summary of various intermolecular contacts in the crystal is obtained from two dimensional fingerprint plot based on the Hirshfeld surface analysis. The close relationship between molecular conformation and the intermolecular interactions for polymorphs I and II using the Hirshfeld surface analysis and their comparative studies will be discussed in the presentation.

Biography :

Email: mmjotani@rediffmail.com