2-Amino-6-methylpyridine based co-crystal salt formation using succinic acid: Single-crystal analysis and computational exploration

Abstract

The current work reports the formation methodology of the co-crystal between 2-amino-6-methylpyridine and succinic acid, its single-crystal characterization, and the computational study. The single-crystal analysis showed that the co-crystal molecules are interlinked by N···H‒O and O···H‒O bonds to form R22 (8) loop and D22 (5) and D22 (8) finite pattern along with the formation of infinite 2D network in the (1 0 1¯) plane having base vectors [1 0 1] and [0 1¯ 0]. Moreover, the weak interactions of the π-π stacking type and CO-Cg interactions are found in the title compound helping in further strengthening of the crystal structure. The Hirshfeld surface analysis confirmed that H···H interatomic contacts are the largest contributor to entire interatomic contacts with contribution of 45.8%. The computational studies supported the presence of significantly strong hydrogen bonds within the title complex. The molecular orbital analysis suggested that both HOMO/HOMO-1 and LUMO/LUMO+1 would be able to participate in oxidative-reductive processes of the complex. The HOMO has dominating contributions from one succinate unit along with minor contributions from the H-bonded NH2-group of the neighboring 2-amino-6-methylpyridin-1-ium moiety. The calculated values of the global reactivity parameters suggest noticeable stability of the title complex. It was also shown to possess quite pronounced nonlinear optical properties.