Crystal structure, optical and electronic properties studies on an hybrid multifunctional MnCl₄-based material

In this research, the multifunctional organic-inorganic hybrid PEA-MnCl₄ [PEA = (C₆H₅–C₂H₄–NH₃)₂] was subjected to single-crystal X-ray diffraction, X-ray diffraction powder, UV-visible spectroscopy, scanning electron microscopy (SEM), and density functional theory, using projector augmented wave (PAW), based on U-Hubbard Hamiltonian (DFT+U) investigations. At 293(2) K, PEA-MnCl₄ crystallizes in Orthorhombic system, Pbca space group (a = 7.202(5) Å, b = 7.293(5) Å, c = 39.386(5) Å, and Z = 8). The optical study reveals that the compound undergoes an indirect optical transition with phonon-assisted Mn²⁺ d-d transitions in the visible region with an energy gap of about 2.14 eV, due to the internal transition of metal (orbital d). The implementation of the Hubbard U term in the calculation using (GGA+U) approximation allows more comprehension on the material behavior and shows that it keeps the antiferromagnetic state. The energy gap calculated (2.07 eV) is in good agreement with the experimental value. The electronic densities of states were computed and analyzed. [Figure not available: see fulltext.]