Synthesis, spectral, thermal, optical and theoretical studies of (2E,6E)-2-benzylidene-6-(4-methoxybenzylidene)cyclohexanone

An Operationally Simple and Efficient Synthesis of 7-Benzylidene-substitutedphenyl- 3,3a,4,5,6,7-hexahydro-2H-indazole by Grinding Method

BACKGROUND

An eco-friendly, operationally simple and efficient reaction is shown between various 2,6-bis-(substituted-benzylidene)-cyclohexanones and differently substituted hydrazine in the presence of acetic acid.

METHODS

The reaction between various 2,6-bis-(substituted-benzylidene)-cyclohexanones and differently substituted hydrazine in the presence of acetic acid afforded 7-Benzylidene-substituted-phenyl-3,3a,4,5,6,7- hexahydro-2H-indazole in 74 to 92 % yield in short reaction time using the grindstone technique.

RESULTS AND DISCUSSION

The notable advantages of this method include mild synthetic conditions, weak acid catalysis, and non-hazardous solvent which make this method environmentally safer.

CONCLUSION

In conclusion, we have developed an efficient, simple and eco-friendly method for the synthesis of 7-Benzylidene-substituted-phenyl-3,3a,4,5,6,7-hexahydro-2H-indazole by grinding technique. The notable benefits of this method are waste minimization, no organic solvent required, simple procedure, easy work-up, and clean reaction profile.

Optical, vibrational, NBO, first-order molecular hyperpolarizability and Hirshfeld surface analysis of a nonlinear optical chalcone

The synthesis of (1E,4E)-1,5-di-p-tolylpenta-1,4-dien-3-one (DTDO) was done and its single crystals were grown by slow evaporation solution technique from 4-methylbenzaldehyde, acetone solution at room temperature. Crystal structure is determined by single crystal X-ray diffraction analysis and reveals that it belongs to the monoclinic system with four molecules in the unit cell (space group C2). The emission of green light from the sample confirms the second harmonic generation (SHG) of the specimen responsible for nonlinear optical property. The various vibration patterns of the specimen have been investigated by Fourier transform infrared and Fourier transform Raman spectroscopy. Optimized molecular geometry, vibrational patterns of DTDO are derived from density functional theory (DFT) calculations and the results are compared with experimental one. The molecular stability and bond strengths were investigated by applying the natural bond orbital analysis. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron density with molecular electrostatic potential (MEP). Highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy gaps were calculated. The other molecular properties like charge transfer are explained using Mulliken population analysis and the first-order molecular hyperpolarizability (β) of the specimen is also estimated and SHG efficiency of DTDO was found to be 3.9 times that of KDP. Fingerprint plots and Hirshfeld surfaces were used to locate and analyze the molecular surface and bonding interactions in various methodologies utilized in the establishment of the relative energies.

Growth, crystalline perfection, spectral, thermal and theoretical studies on imidazolium L-tartrate crystals

Transparent optical quality single crystals of imidazolium L-tartrate (IMLT) were grown by conventional slow evaporation solution growth technique. Crystal structure of the as-grown IMLT was determined by single crystal X-ray diffraction analysis. Thermal analysis reveals the purity of the crystal and the sample is stable up to the melting point. Good transmittance in the visible region is observed and the band gap energy is estimated using diffuse reflectance data by the application of Kubelka-Munk algorithm. The powder X-ray diffraction study reveals the crystallinity of the as-grown crystal and it is compared with that of the experimental one. An additional peak in high resolution X-ray diffraction (HRXRD) indicates the presence of an internal structural low angle boundary. Second harmonic generation (SHG) activity of IMLT is significant as estimated by Kurtz and Perry powder technique. HOMO-LUMO energies and first-order molecular hyperpolarizability of IMLT have been evaluated using density functional theory (DFT) employing B3LYP functional and 6-31G(d,p) basis set. The optimized geometry closely resembles the ORTEP. The vibrational patterns present in the molecule are confirmed by FT-IR coinciding with theoretical patterns.