Structure, atomic Hirshfeld surface, spectroscopic studies and magnetic and dielectric properties of new mixed solid solution (NH4)2Mn0.17Cu0.83Cl4⋅2H2O

Abstract

The tetrachlorocupratmanganate dehydrate (NH4)2Mn0.17Cu0.83Cl4⋅2H2O has been prepared and characterized using various physicochemical techniques including Fourier transform infrared and Raman spectroscopies, differential scanning calorimetry and dielectric and magnetic measurements. A preliminary single-crystal X-ray diffraction structural analysis reveals that the title compound belongs to the tetragonal system with P4(2)/mnm space group. The unit cell dimensions are: a = b = 7.5817(2), c = 7.9312(2) Å, with Z = 2. Its crystal structure was determined and refined down to R = 2%. The structure of this compound consists of discrete [Cu/MnCl4⋅2H2O]2− octahedra interleaved with alkali cations. The cohesion and stabilization of the structure are provided by hydrogen bond interactions (N─H…Cl and O─H…Cl) between [NH4]+ cation and [Cu/MnCl4⋅2H2O]2− anion. Hirshfeld surface analysis has been performed to explore the behaviour of these weak interactions. Dielectric measurements confirm the transition temperatures determined using differential scanning calorimetry. The temperature dependence of the magnetic susceptibility was measured in the temperature range 10–300 K at various magnetic field intensities. Magnetic measurements reveal the occurrence of weak ferromagnetic behaviour at low temperature (Tc = 12 K). The ferromagnetic ordering is further confirmed by the presence of hysteresis loops.