title: Experimental (13C NMR, 1H NMR, FT-IR, single-crystal X-ray diffraction) and DFT studies on 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione.
abstract: In this work, 3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione C(10)H(16)N(2)O(2) (I), was synthesized and characterized by (13)C NMR, (1)H NMR, FT-IR, UV-vis spectroscopy and single-crystal X-ray diffraction. DFT method with 6-31G(d,p) basis set has been used to calculate the optimized geometrical parameters, atomic charges, vibrational frequencies and chemical shift values. The calculated vibrational frequencies and chemical shift values are compared with experimental FT-IR and NMR spectra. The results of the calculation shows good agreement between experimental and calculated values of the compound I. The existence of N-H⋯O type intermolecular ve C-H⋯O type intramolecular hydrogen bonds can be deduced from differences between experimental and calculated results of FT-IR and NMR. In addition, the molecular electrostatic potential map and frontier molecular orbitals and electronic absorption spectra were performed at B3LYP/6-31G(d,p) level of theory. HOMO-LUMO electronic transition of 4.90 eV are derived from the contribution of the bands π→π* and n→π* The spectral results obtained from FT-IR, NMR and X-ray of I revealed that the compound I is in predominantly enamine tautomeric form, which was supported by DFT calculations.
authors.affiliation: Atatürk Vocational High School, Gazi University, Ankara, Turkey. nsuleymanoglu@gazi.edu.tr
authors.forename: Nevin
authors.initials: N
authors.lastname: Süleymanoğlu
authors.forename: Reşat
authors.initials: R
authors.lastname: Ustabaş
authors.forename: Yelda Bingöl
authors.initials: YB
authors.lastname: Alpaslan
authors.forename: Fatih
authors.initials: F
authors.lastname: Eyduran
authors.forename: Cengiz
authors.initials: C
authors.lastname: Ozyürek
authors.forename: Nazan Ocak
authors.initials: NO
authors.lastname: Iskeleli
mesh_terms: D018360:Crystallography, X-Ray; D003503:Cyclobutanes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011437:Propylamines / Q000737:chemistry*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
chemical_list: C569802:3,4-bis(isoproylamino)cyclobut-3-ene-1,2-dione; D003503:Cyclobutanes; D011437:Propylamines