Structure of four molecular salts assembled from noncovalent associations between carboxylic acids and aromatic bases containing benzimidazole moiety

Single crystal X-ray diffraction has enabled the elucidation of four examples of benzimidazole-acid salts, novel contributions to the extensive research into the occurrence of benzimidazole-acid compound motifs in organic salts. In their place are a series of motifs in which extensive strong classical NH⋯O/OH⋯O hydrogen bonds (ionic or neutral) combine with other nonconventional weaker interactions. This variety, coupled with the varying geometries and number of acidic groups of the acids employed, has led to the creation of four supramolecular arrays with 3D network structure.All salts were formed in solution and obtained by the slow evaporation technique. The role of weak and strong noncovalent interactions in the crystal packing is analyzed. The results presented herein indicate that the strength and directionality of the NH⋯O, and OH⋯O hydrogen bonds (ionic or neutral) between acids and benzimidazole derivatives are sufficient to bring about the formation of organic salts.

Graphical abstractDue to the weak noncovalent interactions, the compounds displayed 3D framework structure.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Four supramolecular compounds with 3D structure have been prepared and characterized. ► The noncovalent interaction between benzimidazole moiety and carboxylic acids have been analyzed. ► The NH⋯O/OH⋯O hydrogen bond is the primary force in a family of structures containing the OH⋯im synthons. ► The CHO associations have also been discussed.