Synthesis and characterization of three co-crystals of bis(benzimidazole) derivatives with aromatic dicarboxylic acids

Combination of three aromatic carboxylic acids (5-nitroisophthalic acid (H(2)nip), 2,6-naphthalenedicarboxylic acid (H(2)ndc), tetrabromoterephthalic acid (H(2)tbta)) and flexible bis(benzimidazole) derivatives (1,6-bis(2-methylbenzimidazol-1-yl)hexane (L1), 1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene (L2), 1,4-bis(2-methylbenzimidazol-1-yl)butane (L3)), three co-crystals [(H(2)L1)(2+)center dot 2(Hnip)(-)center dot H2O] (1), [(L2)center dot(H(2)ndc)] (2) and [(H(2)L3)(2+)center dot(tbta)(2-)] (3) were synthesized hydrothermally. Single-crystal X-ray diffraction, elemental analysis and IR spectra are employed to characterize 1, 2 and 3. The 2D fingerprint plots and Hirshfeld surfaces of 1, 2 and 3 indicate that the 3D supramolecular network for 1 was generated by N-H center dot center dot center dot O, O-H center dot center dot center dot O, C-H center dot center dot O hydrogen bonds and pi-pi interactions, the 2D sheet for 2 was produced by O-H center dot center dot center dot N hydrogen bonds and pi-pi interactions, and C-H center dot center dot center dot O hydrogen bonds make structures more stable. For 3, the 2D supramolecular layer was yielded by N-H center dot center dot center dot O, C-H center dot center dot center dot O hydrogen bond interactions. Furthermore, thermogravimetric analyses and photoluminescence properties of three compounds were presented.