title: Synthesis, spectroscopic and structural elucidation of 1-butyl-4-[2-(3,5-dimethoxy-4-hydroxyphenyl)ethenyl)]pyridinium chloride tetrahydrate.
abstract: The novel chloride salt of 1-butyl-4-[2-(4-hydroxyphenyl)ethenyl)]pyridine (1), has been synthesized as the tetrahydrate and its structure and properties elucidated in detail spectroscopically, thermally and structurally, using single crystal X-ray diffraction, linear-polarized solid-state IR-spectroscopy, UV-spectroscopy and mass spectrometry. Quantum chemical calculations were performed with a view to supporting and explaining the experimental structural and spectroscopic data. The compound (1) crystallizes in triclinic P1 space group and its unit cell contains two independent 1-butyl-4-[2-(3,5-dimethoxy4-hydroxyphenyl)ethenyl)]pyridinium] cations, differing with respect to the butyl chain torsion angle for which values of 80.0(9) degrees and 173.6(3) degrees are observed. The cations and anions are joined into infinite layers, formed by two different dimers and including solvent molecules. Hydrogen bonds OH...OH(2) (2.814 A), HOH...O(CH(3)) (2.960 A), OH...Cl (2.967 A), HOH...Cl(-) (3.034, 3.188, 3.161 and 3.062 A) and HOH...OH(2) (2.772 A) are observed. For first time in the literature, we are reporting the crystal structure of the dye with the syring-fragment in the molecule. The spectroscopic properties of the novel compound are compared and with those of the corresponding quinoide form (2). Both the forms (1) and (2) are characterized by 21 and 140 nm solvatochromic effects depending of the type of the solvent. The UV-spectroscopic data in solution confirm the formation of classical H-aggregates in polar protic solvent mixture.
authors.affiliation: Institut für Umweltforschung, Universität Dortmund, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany.
authors.forename: B B
authors.initials: BB
authors.lastname: Koleva
authors.forename: T
authors.initials: T
authors.lastname: Kolev
authors.forename: M
authors.initials: M
authors.lastname: Lamshöft
authors.forename: H
authors.initials: H
authors.lastname: Mayer-Figge
authors.forename: W S
authors.initials: WS
authors.lastname: Sheldrick
authors.forename: M
authors.initials: M
authors.lastname: Spiteller
mesh_terms: D018360:Crystallography, X-Ray; D008958:Models, Molecular; D008968:Molecular Conformation; D011726:Pyridinium Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: C546554:1-butyl-4-(2-(3,5-dimethoxy-4-hydroxyphenyl)ethenyl)pyridinium chloride tetrahydrate; D011726:Pyridinium Compounds