Synthesis, SC-XRD structure, spectroscopy, intermolecular interactions, DFT/TD-DFT investigation, and (static, dynamic) NLO properties of (2E,5Z)-3-(4-fluorophenyl)-2-(4-fluorophenylimino)-5-((E)-3-(2-nitrophenyl) allyliden) thiazolidin-4-one

Abstract

This paper describes the synthesis of a novel fluorine-substituted thiazolidin-4-one compound, (2E,5Z) -3-(4-fluorophenyl) -2-(4-fluorophenylimino) -5-((E)-3-(2-nitrophenyl) allyliden) thiazolidin-4-one, abbreviated as F2NTh. Its structure was subsequently characterized by Fourier transform infrared (FTIR), 1H and 13C nuclear magnetic resonance (NMR), UV–Visible, and single crystal X-ray diffraction (SC-XRD). For a better comprehension of the electronic structure of F2NTh, experimental data collected from the X-ray diffraction pattern were then compared to theoretical results computed by the density functional theory (DFT) using both B3LYP and CAM-B3LYP functionals with a 6–311 G (d, p) basis set. Theoretical results exhibited a good correlation with those established through the experimental analysis. To identify intra- and intermolecular interactions, Hirshfeld surface (HS) and reduced density gradient (RDG) analyses were performed. The results, including 2D fingerprint plots, indicated that H…H interactions played a major role, accounting for 23.6 % of the overall intermolecular contacts. To investigate the charge transfer and ascertain the electronic properties of F2NTh, frontier molecular orbitals and global and local chemical reactivity descriptors were studied. By simulating the molecular electrostatic potential (MEP) and using MPA, NPA, ESP, and MC5 atomic charges, reactive sites within the molecule responsible for electrophilic and nucleophilic attacks were identified. Some thermodynamic parameters and functions (enthalpy, heat capacity, and entropy) obtained from spectroscopic data were also examined in the temperature range of 100−1000 K. Finally, to test the title molecule in the non-linear optical (NLO) domain, the corresponding properties were predicted using B3LYP and CAM-B3LYP functionals. The predicted static NLO parameters (μ = 4.93 D, α = 56.23×10−24 esu, β = 28×10−30 esu, and γ = 244.98 × 10−36 esu) revealed highly promising outcomes, exhibiting the molecule's utility in NLO applications. This activity was confirmed by the dynamic NLO parameters showing a high third-order response.