Synthesis, X-ray crystal structure, Hirshfeld surface analysis and DFT studies of (E)-N'-(2-bromo-benzyl-idene)-4-methylbenzohydrazide

Crystal structure, Hirshfeld surface analysis and geometry optimization of 2-hydroxyimino-N-[1-(pyrazin-2-yl)ethylidene]propanohydrazide

The title compound, 2-hy­droxy­imino-N-[1-(2-pyrazin­yl)ethyl­idene]propane­hydrazide, is a ligand able to form polynuclear metal complexes. The mol­ecule is not planar due to a twist between the oxime and amide groups. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds into supra­molecular chains.

In the mol­ecule of the title compound, C₉H₁₁N₅O₂, the oxime and hydrazide groups are situated in a cis-position in relation to the C—C bond linking the two functional groups. The CH₃C(=NOH)C(O)NH fragment deviates from planarity because of a twist between the oxime and amide groups. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds, forming zigzag chains in the [013] and [03] directions.

Synthesis, crystal growth, characterization and DFT investigation of a nonlinear optically active cuminaldehyde derivative hydrazone

Single crystals of (E)-N'-(4-isopropylbenzylidene)isonicotinohydrazide monohydrate (IBIHM) were grown from ethanol by the slow evaporation from solution growth technique at room temperature. The structure was elucidated by single-crystal X-ray diffraction analysis and crystallized in the orthorhombic system with noncentrosymmetric space group P2₁2₁2₁. Optical studies reveal that the absorption was minimum in the visible region and the band-gap energy was estimated using the Kubelka-Munk algorithm. The functional groups were identified by Fourier transform infrared spectral analysis. A scanning electron microscopy study revealed the surface morphology of the grown crystal. Investigation of the intermolecular interactions, crystal packing using Hirshfeld surface analysis and single-crystal X-ray diffraction confirm that the close contacts were associated with molecular interactions. Fingerprint plots of Hirshfeld surfaces are used to locate and analyze the percentage of hydrogen-bonding interactions. The second-harmonic generation efficiency of the grown specimen was superior to that of the reference material, potassium dihydrogen phosphate. The grown crystals were further characterized by mass spectrometry and elemental analysis. Theoretical studies using density functional theory (DFT) greatly substantiated the experimental observations. Large first-order molecular hyperpolarizability (β) of about ∼70× was observed for IBIHM. The efficiency of IBIHM in terms of nonlinear optical response was verified and the molecule displayed greater chemical stability and reactivity.