Growth and Exploration of Novel Organic Single CoCrystals via Structural Mechanical Nonlinear Optical and DFT Analysis

Abstract

The research study focuses on the development and characterization of novel organic single co-crystals with potential applications in nonlinear optics (NLO), namely bis ((diisopropyl)ammonium) dichromate, 8-hydroxyquinolinium phthalate, diisopropylammonium hydrogen squarate and diisopropylammonium pentaborate monohydrate. These crystalline structures have been successfully banked in the prestigious Cambridge Crystallographic Data Centre (CCDC), UK. The research encompasses the synthesis, structural analysis, and evaluation of their optical (Photoluminescence, FTIR, UV-Vis), thermal and mechanical properties, alongside the crystal s morphological prediction. Crystallographic investigations, including Single Crystal X-ray diffraction, were performed to determine molecular arrangements and intermolecular interactions, while UV-visible spectroscopy assessed optical transparency and bandgap characteristics. Nonlinear optical behavior was examined using the Z-scan technique to establish third-order NLO properties. Additionally, Density Functional Theory (DFT) calculations provided insights into electronic structures, charge transfer mechanisms, HOMO-LUMO gap and hyperpolarizability, aligning experimental findings with theoretical predictions. Thermal stability and mechanical robustness were also analyzed using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and microhardness testing to ensure the co-crystals suitability for practical applications. The study highlights the significance of weak hydrogen bonding in stabilizing crystal structures, enhancing their overall functionality. Hydrogen-bridges and interactions have been ascertained by Hirshfeld surface mapping and 2-D fingerprinting techniques. The integration of experimental and computational methods has resulted in a vivid understanding of these materials. The findings open new avenues for developing high-performance NLO materials with potential applications in photonics and optoelectronics. newline