Abstract
The study of imine-bridged organics has been the hot spot synthesis of second order nonlinear optical (SONLO) and photo-responsive materials in recent years. Herein we present a study of synthesis, growth, and characterization of ([paranitrophenyl]imino)benzene (PNPIB) NLO single crystal. The title compound was synthesized in one step by Schiff base formation. PNPIB single crystal of diameter of 40 mmand length 50 mmwas successfully grown by SR method using a seed as the nucleus. The growth rate formula is derived for the SR method. PNPIB single crystals of 10 mmdiameter and 60 mmheight have been grown at an average growth rate of 3 mmper day from the point seed in a glass crystallizer. Almost 100% stable crystal conversion efficiency was achieved. The as grown PNPIB crystals were characterized using single crystal X-ray diffraction (XRD), X-ray powder diffraction (XRPD), Fourier Transform Infrared (FTIR), Ultraviolet-Visible-Near Infrared (UV-Vis-NIR), 1H & 13C NMR spectral studies, dielectric measurement and NLO studies. Single crystal XRD analysis confirms that the grown ingot belongs to the space group of P2 of monoclinic system thus exhibiting noncentrosymmetric structure. The crystalline perfection was assessed by XRPD. The powder diffraction pattern of the grown crystal has been indexed. The presence of C=N bond with intramolecular hydrogen bonding and the protonation of ions were confirmed by FTIR analysis. The UV-Vis-NIR spectrum of the crystal shows that the crystal has a cut-off at 298 nm. The 1H & 13C NMR spectra confirm the molecular structure. The dielectric behaviour was measured in the frequency range 1 KHz - 10 KHz for the temperature range from 30℃ to 170℃. The slight decrease in dielectric constant has been observed as the frequency is increased and the dielectric loss is very low for the entire frequency range. The second harmonic generation (SHG) in the crystal was observed by Kurtz powder technique.
Highlights
Second order non-linear optical (SONLO) materials have recently attracted much attention because of their potential application in emerging optoelectronic technologies [1,2]
The title compound was synthesized in one step by Schiff base formation. PNPIB single crystal of diameter of 40 mm and length 50 mm was successfully grown by SR method using a seed as the nucleus
PNPIB single crystal was synthesized through solventfree reaction mechanism and grown by both slow solvent evaporation technique and S-R method
Summary
Second order non-linear optical (SONLO) materials have recently attracted much attention because of their potential application in emerging optoelectronic technologies [1,2]. Unver et al have reported the structural and NLO properties for some imine bridged aromatic compounds [13,19,20]. A new novel crystalline structure 2-hydroxy-N-[3(5)-pyrazolyl]-1-4-napthoquinone-4-imine was grown by Speranedo et al and the characterization studies such as DSC, TG/DTA, FTIR, HRXRD were carried out [27]. The intermolecular interaction between the carbonyl and the imine groups in the crystalline compounds containing six member heterocycles were identified by Golovina et al [28]. Based on these results our group has been engaged in the synthesis and growth of organic crystalline materials for NLO applications [2931]. The as grown crystals were characterized by XRD, XRPD, FTIR, UV-Vis-NIR, 1H & 13C NMR, NLO and dielectric studies
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
