Crystal structures of three N-(pyridine-2-carbon-yl)pyridine-2-carboxamides as potential ligands for supra-molecular chemistry

Xiaowen Xu; Richard Hoogenboom; Kristof Van Hecke

doi:10.1107/S2056989021008562

Crystal structures of three N-(pyridine-2-carbon-yl)pyridine-2-carboxamides as potential ligands for supra-molecular chemistry

Acta Crystallogr E Crystallogr Commun. 2021 Aug 24;77(Pt 9):958-964. doi: 10.1107/S2056989021008562. eCollection 2021 Sep 1.

Authors

Xiaowen Xu¹, Richard Hoogenboom¹, Kristof Van Hecke²

Affiliations

¹ Supramolecular Chemistry Group, Centre of Macromolecular Chemistry (CMaC), Department of Organic and Macromolecular Chemistry, Ghent University, Krijgslaan 281-S4, B-9000 Ghent, Belgium.
² XStruct, Department of Chemistry, Ghent University, Krijgslaan 281-S3, B-9000 Ghent, Belgium.

Abstract

The synthesis and single-crystal X-ray structures of three N-(pyridine-2-carbon-yl)pyridine-2-carboxamide imides, with or without F atoms on the 3-position of the pyridine rings are reported, namely, N-(pyridine-2-carbon-yl)pyridine-2-carboxamide, C₁₂H₉N₃O₂ (1), N-(3-fluoro-pyridine-2-carbon-yl)pyridine-2-carboxamide, C₁₂H₈FN₃O₂ (2), and 3-fluoro-N-(3-fluoro-pyridine-2-carbon-yl)pyridine-2-carboxamide, C₁₂H₇F₂N₃O₂ (3). The above-mentioned compounds were synthesized by a mild, general procedure with an excellent yield, providing straightforward access to symmetrical and/or asymmetrical heterocyclic ureas. The crystal structures of 1 and 2 are isomorphous, showing similar packing arrangements, i.e. double layers of parallel (face-to-face) mol-ecules alternating with analogous, but perpendicularly oriented, double layers. In contrast, the crystal structure of 3, containing a fluoro- group at the 3-position of both pyridine rings, shows mol-ecular arrangements in a longitudinal, tubular manner along the c axis, with the aromatic pyridine and carbon-yl/fluorine moieties facing towards each other.

Keywords: N-(pyridine-2-carbonyl)pyridine-2-carboxamide; crystal structure; fluorine moieties; supramolecular chemistry.

Grants and funding

This work was funded by Fonds Wetenschappelijk Onderzoek grant AUGE/11/029; Bijzonder Onderzoeksfonds UGent grant 01N03217; Bijzonder Onderzoeksfonds UGent grant 01SC1717; China Scholarship Council grant 201506780014.