Crystal structure and spectral of new hydrazine-pyran-dione derivative: DFT enol <-> hydrazone tautomerization via zwitterionic intermediate, hirshfeld analysis and optical activity studies

摘要

A novel functionalized Schiff base derivative, (E)-3-(1-(2-(9H-fluoren-9-ylidene)-hydrazineyl)ethylidene)-6-methyl-2H-pyran-2,4(3H)-dione, was synthesized via subsequent condensation/tautomerization processes in a high yield. The product was fully characterized using NMR, FT-IR, and single-crystal XRD; the results of DFT simulations were in respectable agreement with crystallographic data. To elucidate the isomerization, the enol hydrazinium tautomerism has been pursued theoretically, suggesting an intramolecular single proton transfer (SPT) from enol (O center dot center dot center dot center dot H) to the closest N=C unit, giving the hy- drazine (N-H) via [N+-H center dot center dot center dot center dot O-]S (6) zwitterionic intermediate. The results of Hirshfeld surface analysis (HSA) and Molecular electronic potential (MEP) were matching the experimental XRD results. Since a number of hydrogen bonding groups, C-H center dot center dot center dot center dot pi and pi center dot center dot center dot center dot pi-stacking interactions were detected experimentally. The optical properties of the desired compound were experimentally and theoretically figure out. (C) 2020 Elsevier B.V. All rights reserved.