title: Structure and conformation of 2,3-diethoxycarbonyl-1-methylpyridinium iodide studied by NMR, FTIR, Raman, X-ray diffraction and DFT methods.
abstract: Computational and spectroscopic properties of 2,3-diethoxycarbonyl-1-methylpyridinium iodide, 1, were studied. The crystal structure of 1 was analyzed by X-ray diffraction. Molecular geometry of title compound has been calculated using the density functional theory (DFT) at B3LYP/6-311G(d,p) level of theory and was compared with the experimental data. Iodide anion interacts electrostatically with the positively charged pyridinium nitrogen atom and via weak CH⋯I(-) hydrogen bonds. In crystals the N-methyl and ethoxycarbonyl groups are disordered in two orientations. The structures of 2 (in vacuum), 3 (in CHCl3) and 4 (in DMSO) optimized by the B3LYP/6-311G(d,p) approach are different than that in crystal 1. The experimental (13)C and (1)H chemical shifts (δexp) of the investigated ester in CDCl3 and DMSO-d6 correlate linearly with GIAO/B3LYP/6-311G(d,p) magnetic isotropic shielding constants calculated according to the screening solvation model (COSMO), δexp=a+b σcalc. The FTIR and Raman spectra of the solid compound are consisted with the X-ray structure.
authors.affiliation: Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60780 Poznań, Poland.
authors.forename: P
authors.initials: P
authors.lastname: Barczyński
authors.forename: M
authors.initials: M
authors.lastname: Ratajczak-Sitarz
authors.forename: Ł
authors.initials: Ł
authors.lastname: Nowaczyk
authors.forename: A
authors.initials: A
authors.lastname: Katrusiak
authors.forename: Z
authors.initials: Z
authors.lastname: Dega-Szafran
authors.forename: A
authors.initials: A
authors.lastname: Komasa
authors.forename: M
authors.initials: M
authors.lastname: Szafran
mesh_terms: D000838:Anions; D003460:Crystallization; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D011726:Pyridinium Compounds / Q000737:chemistry*; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D054159:Torsion, Mechanical; D014961:X-Ray Diffraction
chemical_list: C586805:2,3-diethoxycarbonyl-1-methylpyridinium iodide; D000838:Anions; D011726:Pyridinium Compounds; C014677:1-methylpyridinium
keywords: 2,3-Diethoxycarbonyl-1-methylpyridinium iodide; B3LYP/6-311G(d,p) calculations; Electrostatic interactions; FTIR Raman and NMR spectra; Hydrogen bonds; X-ray diffraction