Single Crystal Growth of N‐Benzyl‐2‐methyl‐4‐nitroaniline by Seeded Czochralski Pulling Technique for NLO and THz Applications

• Published in: Crystal research and technology (1979) Vol. 55; no. 4
• Main Authors: Raju, Kalaivanan, Aruchamy, Mythili, Karuppannan, Srinivasan
• Format: Journal Article
• Language: English
• Published: 01-04-2020
• Subjects: Czochralski method; Hirshfeld analysis; nonlinear optical crystal; single crystal X‐ray diffraction analysis; terahertz wave generation
• ISSN: 0232-1300; 1521-4079
• DOI: 10.1002/crat.201900234

Single crystal of N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA), a potential organic nonlinear optical (NLO) material for terahertz (THz) pulse generation, is grown successfully from diffusion controlled melt environment by Czochralski pulling (Cz) technique and is reported for the first time. A solution grown crystal having habitual morphology is used as a seed with pre‐determined crystal rotations at constant melt temperature of 102 °C. Unit cell structure of melt grown BNA is refined using single crystal X‐ray diffraction (SCXRD) analysis and is compared with that of the solution grown one. Crystal packing with the dominance of intermolecular hydrogen bonding such as C─H…O, N─H─O, and C─H…π is examined using 2D finger print (FP) plot and 3D Hirshfeld surface (HS) analysis. The presence of minimal percentage of voids reflects the good stacking of molecular arrangement in the melt grown crystals when compared to the solution grown ones. Crystalline purity is confirmed by powder X‐ray diffraction (PXRD) analysis. Modes of vibrations of different functional groups present and wide optical transparency of the grown BNA are realized using Fourier‐transform infrared (FTIR) and ultraviolet‐visible‐near infrared (UV–vis–NIR) spectroscopic analyses, respectively. Thermal stability and melting point are confirmed through differential scanning calorimetry (DSC).
Single crystal of N‐benzyl‐2‐methyl‐4‐nitroaniline (BNA), a potential organic nonlinear optical (NLO) material for terahertz (THz) pulse generation, is grown successfully from diffusion controlled melt environment by Czochralski pulling (Cz) technique using an as‐grown seed crystal from acetone solution and reported for the first time. Structural, spectroscopic, optical and thermal studies reveal the superior quality of the grown single crystals.