Crystal structure and EPR investigation of pyrazinamide containing copper (II) 2-nitrobenzoate single crystal

The crystal structure and paramagnetism in the pyrazinamide containing copper(II) 2-nitrobenzoate single crystal were investigated using X-ray diffraction, Fourier-transform infrared spectroscopy, and electron paramagnetic resonance techniques. X-ray diffraction analysis shows that the complex crystallizes in monoclinic system having two molecules in the unit cell. After using curve fitting method to the electron paramagnetic resonance spectra, anisotropic g and hyperfine A tensors were obtained. The local symmetry, spin Hamiltonian parameters, and molecular bonding coefficients of the paramagnetic Cu²⁺ ion were determined. Perturbation approach was applied to the spin Hamiltonian to calculate the g and A values.