Two thread-shaped cations, pyridinium nicotinamide and imidazolium, as their chloride and hexafluorophosphate salts, were studied with regards to complexation with hydrogen-bond-donating acyclic and macrocyclic ligands. In the latter case, the cations form pseudorotaxanes templated by the chloride anion but not hexafluorophosphate. This formation is a function of the coupling of ion-pairing bet...

A new [2]rotaxane host system containing nitro-isophthalamide macrocycle and polyether functionalised pyridinium axle components is prepared via clipping and stoppering synthetic methodologies using chloride anion templation. After removing the chloride anion template, (1)H NMR titration experiments reveal the unique interlocked host cavity to be highly selective for binding chloride and bromid...

The structure of the title salt, (C(6)H(8)N)(2)[CuCl(3.4)Br(0.6)], consists of two 3-methyl-pyridinium cations and a distorted tetra-hedral [CuCl(3.4)Br(0.6)](2-) dianion. Substitutional disorder with Br is exhibited for three of the Cl atoms of the anion, giving a mixed chloride/bromide cuprate(II) anion. In the crystal, inter-molecular N-H⋯Cl hydrogen bonds link two cations to one anion, form...

The isolation of uronic acid-containing glycosaminoglycans from peripheral nerve and spinal cord of monkey was done by combining the cetyl pyridinium procedure and DEAE-Sephadex column chromatography. The constituent analyses of the isolated GAG-fractions indicated that hyaluronic acid, chondroitin-4-sulphate, chondroi tin-6sulphate, heparan sulphate and a testicular hyaluronidase-resistant gal...

The title compound, (C15H14N3)[NiCl4]Cl, comprises an NiII cation tetra-hedrally coordinated by four chloride anions, a non-coordinating chloride anion and an essentially planar terpyridinium trication (tpyH33+), in which the central pyridinium ring forms dihedral angles of 5.7 (2) and 6.0 (2)° with the peripheral pyridinium rings. Three inter-species N-H⋯Cl hydrogen bonds are formed with the C...

We investigated interactions of bispyridinium para-aldoximes N,N'-(propano)bis(4-hydroxyiminomethyl) pyridinium bromide (TMB-4), N,N'-(ethano)bis(4-hydroxyiminomethyl)pyridinium methanosulphonate (DMB-4), and N,N'-(methano)bis(4-hydroxyiminomethyl)pyridinium chloride (MMB-4) with human erythrocyte acetylcholinesterase phosphorylated by tabun. We analysed aldoxime conformations to determine the ...

Differently substituted pyridinium N-heteroarylaminides have been prepared in one step with good yield from N-aminopyridinium iodide and the corresponding heteroaryl chloride. q 2003 Elsevier Ltd. All rights reserved. For many years conjugated heterocyclic N-ylides, a subgroup of mesomeric betaines, have been widely used as building blocks for the synthesis of fused heterocyclic systems and nat...

Fe(III)-meso-tetra(pyridyl)porphyrins are electrocatalysts for the reduction of dioxygen in aqueous acidic solution. The 2-pyridyl derivatives, both the triflate and chloride salts, are more selective for the desired 4e(-) reduction than the isomeric 4-pyridyl complexes. The inward-pointing pyridinium groups influence proton delivery despite their distance from the iron centre.