Structural Characterization of 6-Bromo-5-nitroquinoline-1-oxide: A Quantum Chemical Study and XRD Investigations

The chemical properties of recently synthesized 6-bromo-5-nitroquinoline-1-oxide under a mild reaction condition by regioselective nitration of 6-bromoquinoline-1-oxide at C5 on going our research were investigated as theoretical. The crystal structure of 6-bromo-5-nitroquinoline-1-oxide, C9H5BrN2O3, was determined by X-ray analysis. Crystallized in Pmc21 in the orthorhombic space group with a = 13.6694 (13) Å, b = 9.6036 (10) Å, c = 14.1177 (16) Å, Z = 8, Dx = 1.929 mg/m3. In this study, theoretical calculations were performed using the GaussView 4.1 molecular imaging program and the Gaussian03W packet program. In the ground state, stable structures of the wholes molecule in the gaseous phase are investigated based on Density Functional Theory (DFT). Molecularly optimized geometries, dipole moments, charge density, thermodynamic properties (heat capacity, enthalpy, entropy), chemical shift values (1H NMR and 13C NMR), energies, molecular electrostatic potentials and frontier orbitals (HOMO and LUMO) B3LYP/6-311G(d,p) base set. Thus, the results obtained by the X-ray diffraction method are supported by theoretical foundations. Finally, the distribution of interactions between molecules in the crystal structure of 6-bromo-5-nitroquinoline-1-oxide (3) was investigated by analysis using Hirshfeld surface production and two-dimensional fingerprinting.