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Pyridinium Chloride (pyridinium + chloride)
Selected AbstractsReductive Cyclization of N-(2,4-Dinitrophenyl)pyridinium Chloride by Tin(II) Chloride.CHEMINFORM, Issue 23 2005R. S. Begunov Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis and Chemical Properties of Diacetylenes with Pyridinium and 4,4,-Bipyridinium GroupsHELVETICA CHIMICA ACTA, Issue 5 2010Isao Yamaguchi Abstract Diacetylenes (DAs) having a dipolar D- , -A structure (D=donor: amino group; ,=, -conjugation core; A=acceptor: pyridinium (Py) and bipyridinium (BPy) groups), i.e., 4 (APBPyDA) and 5 (APPyPyDA), or an A- , -A structure, i.e., 7 (DBPyDA) and 8 (PyDA(Cl)), were obtained by 1,:,1 and 1,:,2 reactions of 4,4,-(buta-1,3-diyne-1,4-diyl)bis[benzenamine] (APDA; 3) with 1-(2,4-dinitrophenyl)-1,-hexyl-4,4,-bipyridinium bromide chloride (1,:,1,:,1) (1), 1-(2,4-dinitrophenyl)-4-(pyridin-4-yl)pyridinium chloride (2), or 1-(2,4-dinitrophenyl)pyridinium chloride (6) (Schemes 1 and 2). The anion-exchange reactions of 8 with NaI and Li(TCNQ) (TCNQ,=2,2,-(cyclohexa-2,5-diene-1,4-diylidene)bis[propanedinitrile] radical ion (1,)) yielded the corresponding I, and TCNQ, salts 9 (PyDA(I)) and 10 (PyDA(TCNQ)). Compounds 10 and 4 exhibited a UV/VIS absorption due to a charge transfer between the TCNQ, and the pyridinium groups and a strong solute,solvent interaction of a dipolar solute molecule in the polar environment, respectively. Compounds 8,10 exhibited photoluminescence in solution, whereas 4 and 7 did not because of the presence of the 4,4,-bipyridinium quenching groups. Differential-scanning-calorimetry (DSC) measurements suggested that the DAs obtained in this study can be converted into poly(diacetylenes) by thermal polymerization. [source] Structural comparison of three N -(4-halogenophenyl)- N,-[1-(2-pyridyl)ethylidene]hydrazine hydrochloridesACTA CRYSTALLOGRAPHICA SECTION C, Issue 7 2010Julia Heilmann-Brohl 2-{1-[(4-Chloroanilino)methylidene]ethyl}pyridinium chloride methanol solvate, C13H13ClN3+·Cl,·CH3OH, (I), crystallizes as discrete cations and anions, with one molecule of methanol as solvent in the asymmetric unit. The N,C,C,N torsion angle in the cation indicates a cis conformation. The cations are located parallel to the (02) plane and are connected through hydrogen bonds by a methanol solvent molecule and a chloride anion, forming zigzag chains in the direction of the b axis. The crystal structure of 2-{1-[(4-fluoroanilino)methylidene]ethyl}pyridinium chloride, C13H13FN3+·Cl,, (II), contains just one anion and one cation in the asymmetric unit but no solvent. In contrast with (I), the N,C,C,N torsion angle in the cation corresponds with a trans conformation. The cations are located parallel to the (100) plane and are connected by hydrogen bonds to the chloride anions, forming zigzag chains in the direction of the b axis. In addition, the crystal packing is stabilized by weak ,,, interactions between the pyridinium and benzene rings. The crystal of (II) is a nonmerohedral monoclinic twin which emulates an orthorhombic diffraction pattern. Twinning occurs via a twofold rotation about the c axis and the fractional contribution of the minor twin component refined to 0.324,(3). 2-{1-[(4-Fluoroanilino)methylidene]ethyl}pyridinium chloride methanol disolvate, C13H13FN3+·Cl,·2CH3OH, (III), is a pseudopolymorph of (II). It crystallizes with two anions, two cations and four molecules of methanol in the asymmetric unit. Two symmetry-equivalent cations are connected by hydrogen bonds to a chloride anion and a methanol solvent molecule, forming a centrosymmetric dimer. A further methanol molecule is hydrogen bonded to each chloride anion. These aggregates are connected by C,H...O contacts to form infinite chains. It is remarkable that the geometric structures of two compounds having two different formula units in their asymmetric units are essentially the same. [source] N -Phenyl- N,-pyridylureas: stereochemical basis for anticonvulsant activityACTA CRYSTALLOGRAPHICA SECTION C, Issue 4 2006Arthur Camerman 4-[N -(2-Chloro-6-methylphenyl)ureido]pyridinium chloride, C13H13ClN3O+·Cl, (CI-953 hydrochloride), crystallizes with Z, = 2 in P. In both molecules, the methyl groups and Cl atoms on the benzene rings are disordered. The benzene rings of molecules A and B adopt two conformations, differing by a rotation of 180° about the C,N bond to the ureido group, in an approximate 1:1 ratio. This disorder is further enhanced by the rotation of the methyl groups in both adopted positions. The pyridine and benzene rings intersect at angles of 102.1,(1) and 111.3,(1)° for A and B, respectively. Hydrogen bonding is mediated by Cl, anions, resulting in indirect connectivity between the molecules. Superposition of the molecular structure, after 180° rotation about an amide bond, with that of phenytoin shows that the chemically different molecules possess stereochemical features in common, which may explain their common activities. [source] |