Search results for "Pyridinium"

4-[4-(4-Fluoro-phen-yl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-3-yl]-1-methyl-pyridinium iodide-4-[3-(4-fluoro-phen-yl)-2-methyl-5-oxo-2,5-dihydro-isoxa…

2007

The crystal structure of the title compound, C(16)H(16)FN(2)O(2) (+)·I(-), was determined as part of a study of the biological activity of isoxazolone derivatives as p38 mitogen-activated protein kinase (MAPK) inhibitors. The X-ray crystal structure of 4-[4-(4-fluoro-phenyl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-3-yl]-1-methyl-pyridinium iodide showed the presence of the regioisomer 4-[3-(4-fluoro-phenyl)-2-methyl-5-oxo-2,5-dihydro-isoxazol-4-yl]-1-methyl-pyridinium iodide. The synthesis of the former compound was achieved by reacting 4-(4-fluoro-phenyl)-3-(4-pyridyl)isoxazol-5(2H)-one after treatment with Et(3)N in dimethyl-formamide, with iodo-methane. The unexpected formation of the regioi…

Indanedione based binary chromophore supramolecular systems as a NLO active polymer composites

2010

Novel route to obtain EO material is proposed by supramolecular assembly of neutral-ground-state (NGS) and zwitterionic (ZWI) NLO chromophores in binary chromophore organic glass (BCOG) host–guest system. On a basis of our Langeven Dynamics (LD) molecular modeling combined with quantum chemical calculations, we have shown that anticipated enhancement NLO efficiency of BCOG material is possible via electrostatic supramolecular assembly of NGS with ZWI chromophore in antiparallel manner. Binding energy of such complex could be more dependent on molecular compatibility of components and local (atomic) charge distribution, then overall molecular dipole moments. According to our LD simulations t…

1992

Synthesis of polymeric 1-iminopyridinium ylides as photoreactive polymers

2010

Two synthetic routes to polymeric 1-imino pyridinium ylides as new photoreactive polymeric architectures were investigated. In the first approach, polymerization of newly synthesized 1-imino pyridinium ylide containing monomers yielding their polymeric analogues was achieved by free radical polymerization. Alternatively, reactive precursor polymers were synthesized and converted into the respective 1-imino pyridinium ylide polymers by polymer analogous reactions on reactive precursor polymers. Quantitative conversion of the reactive groups was achieved with pentafluorophenyl ester containing polymers and newly synthesized photoreactive amines as well as by the reaction of poly(4-vinylbenzoy…

Kinetics of Complex Formation between DNA and Cationically Charged Cylindrical Brush Polymers Observed by Stopped Flow Light Scattering

2009

The complex formation of pUC19 DNA and a cylindrical brush polymer with quaternized poly(vinyl pyridinium) side chains is investigated by stopped flow light scattering (LS). In highly dilute solutions up to two kinetic processes are observable, depending on the mole fraction of anionic charges, x(anion) . For x(anion)  0.4-0.5 only one kinetic process was identified leading to the largest complexes at x(anion)  = 0.4 well below charge stoichiometry. For 0.2 < x(anion)  < 0.4 two kinetic growth processes were identified: The initially formed complexes on the time scale of a few hundred milliseconds keep growing by an unusual fractal growth process until after several minutes they become stab…

Structural variations in amphiphiles: Discoidal multivalent cations

1986

Fourteen cationic multipolar amphiphiles have been synthesized with pyridinium or trimethylammonium head groups. The hydrophobic cores are planar ring systems (benzene or triphenylene) to which two, three, four, or six decylene or undecylene alkyl chains are attached by ester linkages. The hydrophilic head groups are bound to the outer ends of the alkyl chains.

Single-Crystal X-ray Diffraction and Solution Studies of Anion-π Interactions inN-(Pentafluorobenzyl)pyridinium Salts

2014

A solid-state structural study on anion–π interaction in various N-(pentafluorobenzyl)pyridinium salts accompanied by NMR spectroscopic investigations is presented. The crystal structures of 1a–1d reveal different kinds of contacts with anions, including anion–π interactions. In particular, the solid-state structure of 1b-I3 shows distinct evidence of anion–π interactions. Attempts to study anion–π interactions in solution were not successful, but their presence in solution could not be ruled out.

Synthesis of Photoreactive Block Copolymers Based on 1-Iminopyridinium Ylides

2010

Two photoreactive pyridinium ylide containing monomers, {[2-(metacryloyloxy)ethoxy]carbonyl}(pyridinium-1-yl)azanide (M1) and pyridinium-1-yl-(4-vinylbenzoyl)azanide (M2), were synthesized. Both monomers were polymerized under controlled radical polymerization conditions, i.e. reversible addition–fragmentation chain transfer polymerization (M1 and M2) and nitroxide-mediated polymerization (M2). Further block copolymers PMMA-b-PM1 and PS-b-PM2 were successfully synthesized and their molecular weight, Mn, and block ratio could be determined by 1H NMR analysis, thereby opening the synthetic possibilities of photoreactive ylides in block copolymer syntheses.

Densities and viscosities of imidazolium and pyridinium chloroaluminate ionic liquids

2013

Abstract The chloroaluminate ionic liquids are used in various types of reactions. However, due to their particular vulnerability on water, their physical properties have not been previously investigated very extensively. The densities and viscosities of series imidazolium and pyridinium chloroaluminate ionic liquids having alkyl (butyl, hexyl, octyl) or aralkyl (benzyl, ethylphenyl) chain at the cation, various effective molar fraction of AlCl 3 (χ AlCl3  = 0.5, 0.65, 0.7), as well as they mixture and mixture with common organic solvents (hexane, toluene) were measured at the temperature range 293.15–343.15 K (20–70 °C). Densities, and particularly viscosities decrease with the increase of…

Two-Step Synthesis of 2-Aminoindolizines from 2-Alkylpyridines

2014

An efficient method for the synthesis of 2-aminoindolizines by the 5-exo-dig cyclization of 2-alkyl-1-(1-cyanoalkyl)pyridinium salts has been developed. These substrates were prepared by N-alkylation of 2-alkylpyridines with readily available cyanohydrin triflates. The method allows the introduction of various substituents at the 1-, 3-, 6-, 7-, and 8-positions and leaves no undesired acceptor groups in the products.