In the cation of the title salt, C8H11N2 (+)·Br(-), the dihedral angle between the planes of the pyridinium ring and the allyl group is 79.4 (3)°. In the crystal, N-H⋯Br and weak C-H⋯Br hydrogen bonds link the cations and anions, forming chains of alternating R 2 (1)(7) and R 4 (2)(8) rings, which run parallel to the c-axis direction. The crystal studied was an inversion twin with components in...

Condensation and cyclization of 5-hydroxy- 1,2,4- thiadiazol-2-yl hydrazine 1 with pyruvic acid, phenacyl bromide, propargyl bromide and ally1 bromide afforded compounds 2,5,7 3, 4 ,6 and 8 respectively, Reaction of 1 with epichforohydrine afforded 4-hydroxy-N-[5-hydroxy- 1 ,3,4-thiadiazoly1] pyrazolidine 9

The title compound, C(6)H(16)N(3) (+)·Br(-), is the bromide of the monoprotonated aza-macrocyclic triamine 1,4,7-triaza-cyclo-nonane (tacn). The threefold axis of the triamine is broken by the protonation of one of the three amine functions. The ammonium proton is bonded in an intra-molecular symmetrically bifurcated hydrogen bond to the two endodentate amine functions. Direct cation-anion cont...

In the crystal of the title mol-ecular salt, C(7)H(7)N(2) (+)·Br(-), the cations form inversion dimers via weak pairwise C-H⋯N hydrogen bonds; their mean planes are separated by 0.292 (6) Å. Weak C-H⋯Br inter-actions involving all of the remaining H atoms tie the cations and anions together into sets of inter-penetrating sheets. The title compound is isostructural with its iodide analogue.

In the title compound, C(13)H(23)N(2)O(2) (+)·Br(-), the octyl chain has an all-trans conformation. In the crystal, the cations are linked by C-H⋯O bonds into a zigzag chain along the b axis. The bromide anions further link the chains via C-H⋯Br inter-actions into a two-dimensional array parallel to the ab plane. An O-H⋯Br interaction is also observed.

(S)-(1-Pyrrolidin-2-ylmethyl)quinuclidine-1-ium bromide was synthesized in a six-step reaction process starting from l-proline and spectroscopically thermally characterized.

Six different bromide salts - tetraethylammonium bromide ([N2,2,2,2]Br, Br), 1-ethyl-1-methylpiperidinium bromide ([C2MPip]Br, Br), 1-ethyl-1-methylpyrrolidinium bromide ([C2MPyrr]Br, Br), 1-ethyl-3-methylimidazolium bromide ([C2MIm]Br, Br), 1-ethylpyridinium bromide ([C2Py]Br, Br), and 1-(2-hydroxyethyl)pyridinium bromide ([C2OHPy]Br, Br) - were studied in regards to their capacity to form pol...