Synthesis, Spectral Characterization and Fluorescent Assessment of 1,3,5-Triaryl-2-pyrazoline Derivatives: Experimental and Theoretical Studies

Synthesis, Photophysical Properties and Systematic Evaluation of New Class Fluorescein Based Derivative with Organic Solvents: Spectroscopic and Density Functional Theory Methods for Optoelectronic Applications

In this report the photophysical property of newly synthesized fluorescein based derivative 2-(5-((2,4-dichlorophenyl)diazenyl)-6-hydroxy-3-oxo-3H-xanthen-9-yl)benzoic acid has studied by spectroscopic and theoretical that is by Density Functional Theory technique. The structural and functional group of the synthesized molecule was confirmed by nuclear magnetic resonance and fourier transform infrared spectroscopy technique, and from the result so far obtained has been confirmed that molecule has a stable structure and confirmed the presence the functional groups present in the sample. The optical properties of the molecule are studied using the spectroscopic technique and it has revealed the solute-solvent interaction behaviour of the molecule and it has been observed that the bathochromic shift was of about 5 nm, from the fluorescence measurement it has revealed that the emission has been observed at green region and from the power spectra it has been confirmed the same. The DFT study has been derived for the synthesized molecule the optimized structure, electrostatic potential maps, theoretical energy band gap and HOMO and LUMO visualizations are derived from the Gaussian 09W software and it has been found that the bandgap energy is found to be 2.607 eV for benzene solvent and 3.081 eV in methanol solvent, the electrophilic and nucleophilic sites exhibited at the substitution group of the molecule. The outcomes of the study clearly endorse the synthesized fluorescein derivative suitable for photonic/optoelectronic applications.

3-(2,5-Dichlorothiophen-3-yl)-5-(2,4-dimethoxyphenyl)-1-methyl-4,5-dihydro-1H-pyrazole

In the title compound, C16H16Cl2N2O2S, the pyrazole ring has an envelope conformation with the C atom bearing the phenyl ring being the flap. The dihedral angles between the central pyrazole ring (all atoms) and pendant thiophene and phenyl rings are 2.00 (14) and 81.49 (12)°, respectively. In the crystal, weak C—H...O, Cl...π and π–π stacking interactions link the molecules into a three-dimensional network.

Comparative DFT Computational Studies with Experimental Investigations for Novel Synthesized Fluorescent Pyrazoline Derivatives

A novel series of pyrazoline derivatives were synthesized and their spectral properties were characterized via FT-IR, ¹H, and ¹³C NMR. The electronic transitions and fluorescence properties were tracked via UV-Vis and emission spectrometry. The density functional theory (DFT) calculations have been also computed to get spot onto the geometry, electronic transitions and spectroscopic properties theoretically that has been compared with the encountered experimental ones. Moreover, the dipole moment, optimized energy, HOMO - LUMO energies and band gaps were calculated for novel candidates pyrazoline derivatives with highly fluorescence quantum yield.