Preparation, crystallographic feature, and Hirshfeld surface
analysis of two organic salts based on 1,2-diaminobenzene,
trichloroacetic acid and 4-nitro-phthalic acid

Two salts of 1,2-diaminobenzene (dab) as acceptor with the trichloroacetic acid and 4-nitrophthalic acid as donor were prepared and featured by the multiple analytical techniques of FTIR, elemental analysis (EA), and single crystal X-ray diffraction (SCXRD). The structural studies tell that the cation and anion are joined together by the energetic N⁺–H⋯O^– H-bonds due to the transfer of the proton from the donor to the acceptor. The salts show well resolved proton transfer bands in the regions where neither the donor nor the acceptor has any IR peaks. Spectrophotomeric and crystallographic studies have ensured the formation of 2:1/1:1 salts. The chief non-covalent interactions were counted via the Hirshfeld surface analysis. Despite variations of the carboxylic acids, there both bore the strong intermolecular N–H⋯O H-bonds. Apart from the strong classical H-bonds, other supramolecular associates of O–O, Cl–C/Cl–O/Cl–Cl, CH–O, C–π, and π–π are also involved in the spatial stretchings. The anionic C7 chain was built at 2 by the O–H⋯O H-bonds. The roles of these non-covalent contacts are made clear. For the combination of the weak contacts, both salts exhibited the 3D views.

This is an excerpt of the article

Preparation, Crystallographic Feature, and Hirshfeld Surface
Analysis of Two Organic Salts Based on 1,2-diaminobenzene,
Trichloroacetic acid and 4-nitro-phthalic Acid.

Full text of the paper is published in Journal of Structural Chemistry.
DOI: 10.1134/S0022476625090069