P.B. Davidovich, D.S. Novikova, V.G. Tribulovich, S.N. Smirnov, V.V. Gurzhiy, G. Melino, A.V. Garabadzhiu
”First X-ray Structural Characterization of Isatin Schiff-Base Derivative. NMR and Theoretical Conformational Studies”
Journal of Molecular Structure, 2014, 1075, 450-455
DOI: 10.1016/j.molstruc.2014.07.008
Isatin (1H-indole-2,3-dione) is an endogenous natural compound under intense development in medicinal chemistry. Here, we characterize isatin Schiff base derivative by X-ray crystallography. We describe a derivative that crystallizes E-isomer form in the triclinic space group P1; a=5.9580 (4) Å, b=8.4184 (7) Å, c=14.1801 (14) Å, α = 73.962 (8)°, β =83.184 (7)°, γ = 81.143 (6)°. NMR data show that E-conformer interconverts to the Z-conformer when dissolved, this equilibrium weakly depends on the solvent type. The Z-isomer geometry and the energetics of ΔEE-Z interconversion barriers were determined by quantum chemical calculations. The isomers are further characterized by means of FT-IR and UV-Vis spectroscopy.