Synthesis, Crystal Structure, Density Functional Theory (DFT) Calculations and Molecular Orbital Calculations of 4-Bromoanilinium Perchlorate Single Crystal

The non-covalent interactions have an extensive impact on the physical, chemical and biological activity of materials. A new anilinium derivative, 4-bromoanilinium perchlorate (4BAP), has been synthesized, and its structure was determined by single-crystal X-ray diffraction analysis. The quantum chemical calculation tools are implemented to explore the electronic and structural properties of 4BAP. The lattice parameters of the crystal structure are a = 5.0752 (8), b = 7.0540 (11), c = 13.5360 (2) Å, α = 91.073 (5)°, β = 90.991 (5)° and γ = 105.052 (5)°, with 2 molecules per unit cell (Z = 2). In the crystal structure of 4BAP, N-H⋯O hydrogen bond interactions dominate. Along the b-axis, the molecules strongly interact through N1-H3⋯O4 hydrogen bonds, and the hydrogen bonding links the molecules into extended chains running along the b-axis. The more delocalized electrons around the aromatic ring may influence the nonlinear activity of the materials. NBO results suggested more electron delocalization around the aromatic ring, which suggests that the title molecule could be used for nonlinear optical applications. The feasible reactivity tendency was determined from the frontier molecular orbital (FMO) analysis. The H...H interactions account for 9.8% of the surface area, and the crystal structure can accommodate a higher fraction of hydrogen atoms. The calculated values of dipole moment, polarizability and first-order hyperpolarizability are 13.5028 D, 20.504 × 10−24 esu and 2.1218 × 10−30 esu, respectively