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: C8H14O4·2(C6H4N2), C5H7N2·NCS, and Ni(CN)4·2(C5H7N2)·2(H2O) for compounds 1, 2, and 3, respectively. Crystallographic analysis showed that the compounds crystallize in the space groups P1̄, P21/n and C2/m, respectively. Their molecular packing is stabilized by a network of hydrogen bonds (C-H···O, O-H···N, N-H···N, N-H···S, O-H···N, and N-H···O) and noncovalent interactions (C-H···μ and μ···μ). Computational studies using Gaussian 03 and CrystalExplorer further elucidated their structural, magnetic, electrooptic, and electrochemical properties.