N, N'-Bis(pyridin-4-ylmeth-yl)oxalamide benzene monosolvate: crystal structure, Hirshfeld surface analysis and computational study

Acta Crystallogr E Crystallogr Commun. 2019 Jul 9;75(Pt 8):1133-1139. doi: 10.1107/S2056989019009551. eCollection 2019 Aug 1.

Abstract

The asymmetric unit of the title 1:1 solvate, C14H14N4O2·C6H6 [systematic name of the oxalamide mol-ecule: N,N'-bis-(pyridin-4-ylmeth-yl)ethanedi-amide], comprises a half mol-ecule of each constituent as each is disposed about a centre of inversion. In the oxalamide mol-ecule, the central C2N2O2 atoms are planar (r.m.s. deviation = 0.0006 Å). An intra-molecular amide-N-H⋯O(amide) hydrogen bond is evident, which gives rise to an S(5) loop. Overall, the mol-ecule adopts an anti-periplanar disposition of the pyridyl rings, and an orthogonal relationship is evident between the central plane and each terminal pyridyl ring [dihedral angle = 86.89 (3)°]. In the crystal, supra-molecular layers parallel to (10) are generated owing the formation of amide-N-H⋯N(pyrid-yl) hydrogen bonds. The layers stack encompassing benzene mol-ecules which provide the links between layers via methyl-ene-C-H⋯π(benzene) and benzene-C-H⋯π(pyrid-yl) inter-actions. The specified contacts are indicated in an analysis of the calculated Hirshfeld surfaces. The energy of stabilization provided by the conventional hydrogen bonding (approximately 40 kJ mol-1; electrostatic forces) is just over double that by the C-H⋯π contacts (dispersion forces).

Keywords: Hirshfeld surface analysis; benzene solvate; bis­(4-pyridyl­meth­yl)oxalamide; computational chemistry; crystal structure; hydrogen bonding.

Grants and funding

This work was funded by Sunway University Sdn Bhd grant STR-RCTR-RCCM-001-2019.