Abstract
The synthesis of p-toluidinium perchlorate (systematic name: 4-methyl-anilinium perchlorate), C(7)H(10)N(+)·ClO(4)(-), was carried out from an aqueous reaction of perchloric acid with p-toluidine. This compound was characterized by powder XRD, IR and UV-Vis spectroscopy. The structure was further confirmed by a single-crystal X-ray diffraction study. The crystal structure is formed by a succession of two-dimensional mol-ecular layers consisting of perchlorate anions and organic cations parallel to the (100) plane and located at x = 2n + ½ (n ∈ Z). Each mixed layer is formed by infinite chains {C(7)H(10)N(+)·ClO(4)(-)} (n) parallel to the [010] direction and developing along the c axis, generating R(2)(4)(8), R(2)(2)(4) and R(4)(4)(12) graph-set motifs. The results of a theoretical study using the DFT method at the B3LYP/6-311++G(d,p) level are in good agreement with the experimental data. Hirshfeld surface and fingerprint plots reveal that the structure is dominated by O⋯H/H⋯O (54.2%), H⋯H (26.9%) and C-H ⋯π (14.3%) contacts. The studied crystal was refined as a two-component twin.