Experimental and theoretical investigation of the molecular and electronic structure of 3-ethoxy-4-isopropylaminocyclobut-3-ene-1,2-dione.
The title compound, 3-ethoxy-4-isopropylaminocyclobut-3-ene-1,2-dione (EIAC) has been synthesized and characterized by NMR, FT-IR, UV-vis spectroscopy and single-crystal X-ray diffraction. The (1)H NMR spectra were recorded at 300 K and 315 K in CDCl(3) to determine syn/anti conformers of the compound EIAC. Density functional theory (DFT) calculations, optimized geometrical parameters, vibrational frequencies and chemical shift values of syn/anti conformer in CDCl(3) have been performed at B3LYP/6-311G(d) level, and compared with the experimental data. The values provided with the calculations support the experimental data of the compound EIAC. The presence of NH⋯O type intermolecular H bond can be perceived from the difference between experimental calculations and results of FT-IR and NMR calculations. In addition, B3LYP/6-311G(d) basis set has been used to calculate the molecular electrostatic potential, frontier molecular orbitals and electronic absorption spectra. HOMO-LUMO electronic transition of 5.12 eV is derived from the contribution of the bands n→σ(*) or π→π(*). FT-IR, NMR and X-ray spectral results and additionally DFT calculations exhibit that the compound EIAC exists in keto-enamine tautomeric form. The experimental (1)H NMR spectra recorded at 300 K and 315 K and theoretical (1)H NMR data indicate that the compound EIAC is in syn conformer.
Atatürk Vocational High School, Gazi University, 06760 Çubuk, Ankara, Turkey. nsuleymanoglu@gazi.edu.tr
Nevin
N
Süleymanoğlu
Reşat
R
Ustabaş
Yelda Bingöl
YB
Alpaslan
Fatih
F
Eyduran
Nazan Ocak
NO
İskeleli
D000042:Absorption; D018360:Crystallography, X-Ray; D003503:Cyclobutanes / Q000737:chemistry*; D004583:Electrons; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity; D013237:Stereoisomerism; D013816:Thermodynamics; D014732:Vibration
C110624:3-cyclobutene-1,2-dione; D003503:Cyclobutanes