Crystal structure, hydrogen bonding and Hirshfeld surface analysis of 2-amino-4-meth-oxy-6-methyl-pyrimidinium 4-chloro-benzoate

Acta Crystallogr E Crystallogr Commun. 2018 Apr 12;74(Pt 5):656-659. doi: 10.1107/S2056989018005583. eCollection 2018 May 1.

Abstract

In the crystal structure of the title salt, C6H10N3O+·C7H4ClO2-, the dihedral angle between the pyrimidine ring of the 2-amino-4-meth-oxy-6-methyl-pyrimidine cation and the the benzene ring of the 2-chloro-benzoate anion is 2.2 (1)°. In the anion, the benzene ring forms a dihedral angle of 8.5 (2)° with the carboxyl group. The pyrimidine N atom of the cation is protonated and the meth-oxy substituent is essentially coplanar with the parent ring. The protonated N atom and the N atom of the 2-amino group are hydrogen bonded to the 4-chloro-benzoate anion through a pair of N-H⋯Ocarbox-yl hydrogen bonds, forming an R22(8) ring motif linked through a centrosymmetric R24(8) ring motif, resulting in a pseudo-tetra-meric DDAA array. These units are linked through inter-molecular meth-oxy C-H⋯Cl hydrogen bonds into ribbon-like chains extending along the c-axis direction. The crystal structure also features π-π stacking inter-actions between the rings in the cation and anion [minimum ring centroid separation = 3.7707 (12) Å].

Keywords: crystal structure; pseudo­tetra­meric; pyrimidine.

Grants and funding

This work was funded by Department of Science and Technology, Ministry of Science and Technology, Science and Engineering Research Board grant SB/FT/CS-058/2013 to P. Sivajeyanthi and K. Balasubramani.