Crystal structure characterization as well as theoretical study of spectroscopic properties of novel Schiff bases containing pyrazole group

A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. All as-synthesized Schiff bases were characterized by means of NMR, FT-IR, and MS; and the molecular geometries of two Schiff bases as typical examples were determined by means of single crystal X-ray diffraction. In the meantime, the ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were also measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method. It has been found that all as-synthesized Schiff bases show a remarkable absorption peak in a wavelength range of 270–370 nm; and their maximum emission peaks are around 344 nm and 332 nm, respectively.

A series of novel Schiff bases containing pyrazole group were synthesized using 1-aryl-3-methyl-4-benzoyl-5-pyrazolone and phenylenediamine as the starting materials. The ultraviolet-visible light absorption spectra and fluorescent spectra of various as-synthesized products were measured. Moreover, the B3LYP/6-1G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases; and the spectroscopic properties of the products were computed and compared with corresponding experimental data based on cc-pVTZ basis set of TD-B3LYP method.Figure optionsDownload as PowerPoint slideHighlights
► A series of novel Schiff bases containing pyrazole group were synthesized and characterized.
► The UV–Vis spectra and fluorescent spectra of various as-synthesized products were measured.
► The B3LYP/6-31G(d,p) method was used for the optimization of the ground state geometry of the Schiff bases.
► The spectroscopic properties of the Schiff bases were computed based on cc-pVTZ basis set of TD-B3LYP method.