Structural Characterization of Di- and Mono-Imidazolyl-Substituted 1,8-Naphthyridine Derivatives

Abstract  Two imidazolyl derived 1,8-naphthyridine compounds (2,7-diimidazolyl-1,8-naphthyridine (a), and 2-benzimidazolyl-5,7-dimethyl-1,8-napthyridine (b)) were synthesized and structurally characterized by X-ray crystallography. The compound a co-crystallizes with one ethanol and two water molecules to give compound 1. Compound 1 crystallizes in the triclinic, space group P-1, with a = 6.943(2) ?, b = 9.009(3) ?, c = 13.760(3) ?, α = 96.793(2)°, β = 97.431(3)°, γ = 107.080(2)°, V = 804.6(4) ?³, Z = 2. Compound 1 forms a 3D interpenetrated network through hydrogen bonds. Compound b co-crystallizes with three and one half water molecules to form 2. Compound 2 crystallizes in the monoclinic, space group C2/c, with a = 24.926(8) ?, b = 10.608(3) ?, c = 16.751(5)?, β = 110.133(4)°, V = 4159(2) ?³, Z = 8. The free water molecules form six-membered rings, these water rings connect the naphthyridine to form one dimensional chain when viewed from b axis. The naphthyridyl rings in a and b axis are connected through C–H···π, and π–π interactions, due to the weak interactions the compound shows 3D network structure. Graphical Abstract  Due to the weak interactions, the naphthyridine derivatives showed 3D network structure.