Crystal structure analysis, magnetic measurement, DFT studies, and adsorption properties of novel 1-(2,5-dimethyphenyl)piperazine tetrachlorocobaltate hydrate

Present study focuses on the synthesis, crystal structure analysis,density functional theory (DFT), and the potential of 1-(2,5-dimethyphenyl) piperazine tetrachlorocobaltate hydrate (C12H20N2) CoCl4·H2O as adsorbent material for small moleculesas: CO2, H2CO, H2S, NH3, and NO2 gas.To gain insight into the geometrical properties, Infrared spectrum, and the intermolecular interactions within the crystal structure, X-ray crystallography, Fourier transform infrared spectroscopy (FT-IR), and Hirshfeld analysis have been carried out.The calculated adsorption energies follow a decreasing pattern of Hybrid-NO2 > Hybrid-NH3 > Hybrid-H2S > Hybrid-H2CO > Hybrid-CO2. It is evident that Hybrid-NO2 reflects the highest adsorption energy of − 0.5235 eV, depicting that the hybrid will better adsorb NO2 gas as compared to other gases. In all cases,the adsorption phenomena are best described as chemisorptions owing to the negative adsorption magnitudes.In furtherance, the magnetic susceptibility measured over a range of 2 – 300 K reveals paramagnetic behavior with weak magnetic interactions between Co(II) ions. At 300 K, theχpTvalue reflects 2.461 emu K mol–1, indicating a spin-orbit coupling contribution to the spin-only value of 1.875 emu K mol–1 expected for Co(II) with 3d7 spin configuration.