title: Molecular and crystal structures, vibrational studies and quantum chemical calculations of 3 and 5-nitroderivatives of 2-amino-4-methylpyridine.
abstract: The crystal structures of 2-amino-4-methyl-3-nitropyridine (I), 2-amino-4-methyl-3,5-dinitropyridine (II) and 2-amino-4-methyl-5-nitropyridine (III) have been determined. The compounds crystallize in the monoclinic P2(1)/n, triclinic P-1 and monoclinic C2/c space groups, respectively. These structures are stabilized by a combination of N-H···N and N-H···O hydrogen bonds and exhibit layered arrangement with a dimeric N-H···N motif in which the molecular units are related by inversion centre. The molecular structures of the studied compounds have been determined using the DFT B3LYP/6-311G(2d,2p) approach and compared to those derived from X-ray studies. The IR and Raman wavenumbers have been calculated from the optimized geometry of monomers and dimers formed in the unit cell and compared to the experimental values obtained from the spectra.
authors.affiliation: Department of Bioorganic Chemistry, Institute of Chemistry and Food Technology, Faculty of Engineering and Economics, Wrocław University of Economics, 118/120 Komandorska, Wrocław 53-345, Poland. isai@o2.pl
authors.forename: I
authors.initials: I
authors.lastname: Bryndal
authors.forename: E
authors.initials: E
authors.lastname: Kucharska
authors.forename: W
authors.initials: W
authors.lastname: Sąsiadek
authors.forename: M
authors.initials: M
authors.lastname: Wandas
authors.forename: T
authors.initials: T
authors.lastname: Lis
authors.forename: J
authors.initials: J
authors.lastname: Lorenc
authors.forename: J
authors.initials: J
authors.lastname: Hanuza
mesh_terms: D018360:Crystallography, X-Ray; D019281:Dimerization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008968:Molecular Conformation; D010847:Picolines / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013059:Spectrum Analysis, Raman; D014732:Vibration
chemical_list: D010847:Picolines; D011725:Pyridines; C015672:2-amino-4-picoline; C023666:pyridine