Synthesis, crystal structure, and non-covalent interactions in 4-hydrazinobenzoic acid hydrochloride

The compound 4-hydrazinobenzoic acid hydrochloride (4-HBA), C7H9O2·Cl, has been synthesized and characterized by FT-IR spectroscopy and X-ray diffraction. The compound crystallizes as colourless needles in a triclinic system, space group Pˉ1 (Z = 2), and cell parameters a = 3.7176 (4) Å, b = 5.9133 (4) Å, c = 19.3631 (13) Å, α = 87.841 (6), β = 88.924 (6), γ = 80.203 (6), V = 419.13 (6) Å3. The component ions are linked by a combination of O–H⋯O, N–H⋯N and N–H⋯Cl hydrogen bonds to form a complex three-dimensional framework structure in which each cation is linked to two other cations, by O–H⋯O and N–H⋯N hydrogen bonds, and to five different anions, while each anion accepts hydrogen bonds from five different cations. Calculations on the Non-Covalent Interactions (NCI) amplify the crystallographic conclusions concerning the interionic hydrogen bonds.