1 research outputs found
Study of the Crystal Architecture, Optoelectronic Characteristics, and Nonlinear Optical Properties of 4‑Amino Antipyrine Schiff Bases
Two Schiff bases,
(E)-4-((2-chlorobenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (4AAPOCB) and (E)-4-((4-chlorobenzylidene)amino)-1,5-dimethyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one (4AAPPCB), have been synthesized and grown
as single crystals. Single-crystal X-ray diffraction analysis was
employed to determine the crystal structure of the compounds, and
the results suggest that the compounds crystallized into an orthorhombic
crystal system having P212121 and Pbca space groups, respectively.
Further, the crystallinity of the compounds was analyzed by the PXRD
technique. The UV–vis–NIR spectra of the compounds demonstrate
excellent transmittance in the entire visible region. The lower cutoff
wavelengths of the compounds were determined to be 338 and 333 nm,
respectively; additionally, optical band gaps of the compounds found
were 4.60 and 4.35 eV. FTIR and NMR (1H and 13C) spectral techniques were utilized to analyze the molecular structure
of the compounds. The compounds emit photoluminescence with broad
emission bands with centers at 401 and 418 nm. The thermal stability
and phase transitions were assessed through thermogravimetric methods.
The phase transition prior to melting was indicated by the endothermic
event at around 190 °C in the DTA curves of both crystals, and
the same was observed in the DSC curves. The second harmonic efficiencies
of the powdered compounds I and II were found to be 3.52 and 1.13
times better than that of the standard reference KDP. The 4AAPOCB
and 4AAPPCB compounds showed isotropic polarizability amplitudes of
46.02 × 10–24 and 46.52 × 10–24 esu, respectively. The calculation of linear polarizability and
NLO second-order polarizability (β) along with other optical
parameters was performed for optimized geometries. The nonzero amplitudes
of the average β values for compounds 4AAPOCB and 4AAPPCB were
found to be 14.74 × 10–30 and 8.10 × 10–30 esu, respectively, which show a decent potential
of the synthesized molecules for NLO applications. The calculated
β amplitudes were further explained based on calculated electronic
parameters like molecular electrostatic potentials, frontier molecular
orbitals, molecular orbital energies, transition energies, oscillator
strengths, and unit spherical representation of NLO polarizability.
The current analysis emphasizes the significance of synthesized compounds
as prospective candidates for optical and NLO applications through
the use of experiments and quantum computations