Molecular and crystal structure of 1-methyl- 5-trifluoromethoxy-1H-indole-2,3-dione 3-[4-(4-methoxyphenyl)thiosemicarbazone]

Authors : Özge SOYLU ETER, Zeliha ATİOĞLU, Mehmet AKKURT, Cem Cüneyt ERSANLI, Nilgün KARALI

Pages : 59-66

View : 35 | Download : 8

Publication Date : 2021-04-30

Article Type : Research Paper

Abstract :Background and Aims: The main purpose of this study is to determine the molecular structure and isomers of the new 1-methyl- 5-trifluoromethoxy-1H-indole-2,3-dione 3-[4-insert ignore into journalissuearticles values(4-methoxyphenyl);thiosemicarbazone] insert ignore into journalissuearticles values(5); and to prove the 3Z-conformer of the compound 5. Methods: The molecular structure of E- and Z-isomer mixture 5 was confirmed by analytical and spectral data insert ignore into journalissuearticles values(UV, IR, 1H NMR, HSQC-2D and MS);. The Z-conformer of compound 5 was characterized by NMR spectroscopy and X-ray single crystal diffraction analysis method insert ignore into journalissuearticles values(SC-XRD);. Results: The compound 5 was synthesized by condensation of 1-methyl-5-trifluoromethoxy-1H-indole-2,3-dione insert ignore into journalissuearticles values(2); with 4-insert ignore into journalissuearticles values(4-methoxyphenyl);thiosemicarbazide insert ignore into journalissuearticles values(4);. The compound 5 was obtained in two separate forms, crystal and amorphous. It was proved by NMR data and X-ray diffraction findings that the crystal form is the Z-isomer and the amorphous form is a mixture of the E- and Z-isomers. The E- and Z-isomer ratios were determined by 1H NMR spectroscopy. The crystal structure and molecular interactions of the Z-conformer were determined by X-ray single crystal diffraction analysis. Conclusion: In the crystal, three intramolecular N—H···N, N—H···O and C—H···S hydrogen bonds provided isomer formation. Also, molecular packing was stabilized by intermolecular C—H···O hydrogen bonds, the π-π stacking interactions and weak CO···π insert ignore into journalissuearticles values(ring); contacts.
Keywords : Synthesis, molecular structure, isomerism, crystal structure, hydrogen bond, π π stacking interaction

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