Structural,spectral, experimental,and theoretical investigations of (E)-4-fluoro-N′-(pyridin-2-ylmethylene)benzohydrazide monohydrate

The structural and nonlinear optical properties of the Schiff base material, (E)-4-fluoro-N′-(pyridin-2-ylmethylene)benzohydrazide monohydrate (FPMBH) were studied. The experimental investigations were performed using Fourier transform infrared (FTIR), ultraviolet (UV) and nuclear magnetic resonance (NMR) spectral techniques. The computational analyses were made by DFT method. A comparison between experimental and theoretical predictions was made and interpreted. The maximum absorption wavelength was found by both experimental and theoretical analyses. The Hirshfeld surface analysis was performed to understand the various molecular interactions. Highest occupied and lowest unoccupied molecular orbitals (HOMO–LUMO) analysis was performed for the title molecule to know about the possible charge transfer taking place within the molecule. Reactivity features were also determined by molecular electrostatic potential (MEP) analysis. The third-order nonlinear optical studies were done by z-scan experiment, and the results were discussed.

     

Desired form of polymorphism of 6-chloro-2,4-dinitroaniline crystals grown by controlled growth temperature in melt growth

In this paper, the important form of a polymorphism of 6-chloro-2,4-dinitroaniline (CDA) crystals grown by the melt growth technique and its structure, physical, properties were discussed. Single crystals of form II and form III were grown by spontaneous nucleation of CDA melt. Unit cell parameters of these two forms were determined by the single-crystal X-ray diffraction technique. A powder X-ray diffraction pattern obtained from single-crystal data was compared with the experimental pattern. Functional groups presented in the molecules were identified by FTIR spectra, and packing difference between the two forms was realized by splitting of the absorption band and inter- and intramolecular interaction. DSC and TG/DTA analyses confirmed that each form has its own melting peak around 160 (form II) and 162 °C (form III) and there is no phase transition occurring between these forms. Harmonic vibrational frequency (β) of CDA was evaluated theoretically using HF/6-31G level and this value was compared with the experimental Kurtz–Perry technique. The calculated HOMO-LUMO energy shows that charge transfer occurred within the molecules.     

α-Fe2O3@carbon core–shell nanostructure for luminescent upconversion and photocatalytic degradation of methyl orange

Research on Chemical Intermediates - The unique characteristics of metal–organic frameworks such as structural tunability, high surface area, low density, and tailored porosity have made this...     

Effect of doping an organic molecule ligand on TGS single crystals

Good quality single crystals of thiourea-doped triglycinesulphate (TuTGS) a new semiorganic nonlinear optical (NLO) crystal has been successfully grown from aqueous solution by slow evaporation method. The solubilities under various solvents in different proportions have been studied. The structural characterization of the grown crystals was carried out by X-ray diffraction. The grown crystals were subjected to FTIR and Raman analyses for vibrational assignments. The optical absorption coefficient alpha was analysed and interpreted to be allowed in the direct transition. The values of allowed direct energy gap (Eg) for undoped and doped crystals were calculated. It was found that Eg values were decreased with organic molecule doping. The powder technique of Kurtz and Perry confirm the NLO property of the grown crystal.