title: Synthesis, crystal structure, and spectroscopic properties of new stilbazolium salt with enlarged π-conjugated system.
abstract: A new stilbazolium dye 4-{(E)-2-[4-(dimethylamino)naphthalen-1-yl]ethenyl}-1-methylquinolinium iodide monohydrate (DANSQI) having enlarged π-conjugated system was synthesized and characterized by X-ray diffraction, IR, Raman, UV-Vis, Fluorescence, (1)H- and (13)C NMR spectroscopy. Quantum chemical calculations were performed to obtain electronic structure and vibrational data, using DFT. The crystals are monoclinic, space group P21/n, with a=8.0751(14), b=25.839(4), c=10.9031(15) Å, V=2141.4(6) Å(3), and Z=4 (at 300(2) K). The unit cell contains four molecules of the dye, participating in weak intermolecular interactions. The cation is nearly flat with a deviation of the planarity of 5.08 (1)°. The dye investigated is the first stilbazolium iodide containing water molecule in the solid state therefore the N-dimethylamino group declines significantly from planarity, as indicated by C13N1C2C3 torsion angle of 16.08°. The dye studied shows solvatochromism of 84 nm in visible region and very large Stokes shift up to 253 nm. The intensity of fluorescence bands strongly depends on solvent polarity.
authors.affiliation: Plovdiv University, Faculty of Chemistry, 24 Tzar Assen Str., 4000 Plovdiv, Bulgaria. mtodorova@uni-plovdiv.bg
authors.forename: Mina
authors.initials: M
authors.lastname: Todorova
authors.forename: Rumyana
authors.initials: R
authors.lastname: Bakalska
authors.forename: Tsonko
authors.initials: T
authors.lastname: Kolev
mesh_terms: D015057:1-Naphthylamine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry; D001597:Benzylidene Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D002725:Chloroform / Q000737:chemistry; D018360:Crystallography, X-Ray; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D008968:Molecular Conformation; D011806:Quinolinium Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D012996:Solutions; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: C583707:4-(2-(4-(dimethylamino)naphthalen-1-yl)ethenyl)-1-methylquinolinium; D001597:Benzylidene Compounds; D011806:Quinolinium Compounds; D012996:Solutions; D012997:Solvents; D002725:Chloroform; D015057:1-Naphthylamine; D000432:Methanol