Synthesis, characterization, and theoretical study of new cocrystals and charge-transfer compounds

This study used single-crystal X-ray diffraction, elemental analysis, infrared (IR) spectroscopy, theoretical nuclear magnetic resonance (NMR), and theoretical ultraviolet spectroscopy to characterize 3 newly synthesized crystalline compounds. Additionally, the nonlinear optical, highest occupied molecular orbital energies, lowest occupied molecular orbital energies, band gap, molecular electrostatic potential, and thermodynamic parameters of the 3 crystalline compounds were examined. The strong correlation between experimental IR spectra and theoretical NMR chemical shifts confirmed the accuracy of computational predictions. The molecular formulas of the 3 newly synthesized crystalline compounds, each containing different ligand molecules, were: C8H14O42(C6H4N2), C5H7N2NCS, and Ni(CN)42(C5H7N2)2(H2O) for compounds 1, 2, and 3, respectively. Crystallographic analysis showed that the compounds crystallize in the space groups P1, P21/n and C2/m, respectively. Their molecular packing is stabilized by a network of hydrogen bonds (C-H center dot center dot center dot O, O-H center dot center dot center dot N, N-H center dot center dot center dot N, N-H center dot center dot center dot S, O-H center dot center dot center dot N, and N-H center dot center dot center dot O) and noncovalent interactions (C-H center dot center dot center dot pi and pi center dot center dot center dot pi). Computational studies using Gaussian 03 and CrystalExplorer further elucidated their structural, magnetic, electrooptic, and electrochemical properties.