Facile Synthesis, Spectroscopic, and Optical Nonlinear Properties of Hydrazinylthiazole‐Based Functional Materials: A Combined Experimental and DFT Approach

ABSTRACT Hydrazinylthiazole‐based chromophores ( 7a – 7g ) were synthesized via condensation method, and their structures were confirmed using various spectroscopic techniques. The key electronic and nonlinear optical properties of the synthesized chromophores were investigated at the M06/6‐311G (d,p) level. The computed HOMO–LUMO energy gaps (4.492–4.028 eV) with UV‐Visible spectra appear between 328.609 and 389.581 nm suggest suitable intramolecular charge transfer and optical activity in entitled compounds. NBOs analysis provides valuable insights into the noncovalent interactions contributing the stability of the studied compounds. All compounds exhibited significantly higher values of dipole moment ( μ tot ), average linear polarizability (⟨ α ⟩), first hyperpolarizability ( β tot ), and second hyperpolarizability ( γ tot ) compared with urea and p ‐NA (used as a standard for NLO study). Notably, 7g compound exhibited the smallest energy gap (4.028 eV) and red‐shifted absorption ( λ max = 328.609 nm) with the highest hyperpolarizabilities ( β tot = 2.09 × 10 −29 ; γ tot = 7.87 × 10 −35 esu). The outcomes of this study illustrated them as good candidates for NLO materials.