Search results for "Onium"
showing 10 items of 2091 documents
Synthesis of novel fluorinated building blocks via halofluorination and related reactions.
2020
A study exploring halofluorination and fluoroselenation of some cyclic olefins, such as diesters, imides, and lactams with varied functionalization patterns and different structural architectures is described. The synthetic methodologies were based on electrophilic activation through halonium ions of the ring olefin bonds, followed by nucleophilic fluorination with Deoxo-Fluor®. The fluorine-containing products thus obtained were subjected to elimination reactions, yielding various fluorine-containing small-molecular entities.
Dependence of the distortion of the square pyramids in N,N-dimethylethylenediammonium pentachloroantimonate(III) on the geometry of hydrogen bonds
2001
Abstract N ,N-Dimethylethylenediammonium pentachloroantimonate(III) crystallizes in the monoclinic system, in space group P21/c (a = 12.460(2), b = 10.252(2), c = 10.330(2) Å, β = 97.75(3)°, V = 1307.5(4) Å3, Z = 4, dc = 1.997, dm = 1.99(2) g/cm3). The crystal structure of [(CH3)2NH(CH2)2NH3][SbCl5] consists of isolated [SbCl5]2- anions and [(CH3)2NH(CH2)2NH3]2+ cations. The [SbCl5]2- anion has a distorted square pyramidal geometry, presenting one short axial and four long equatorial Sb-Cl bonds. The square pyramids are characteristically stacked one close to the other, parallel to the c axis. The voids between the anionic sublattice are filled by [(CH3)2NH(CH2)2NH3]2+ cations. The five non…
Phase transitions and distortion of [BiCl6]3– octahedra in (C3H5NH3)3[BiCl6] – DSC and single-crystal X-Ray diffraction studies
2004
The DSC diagram of tris(allylammonium) hexachlorobismuthate(III), (C3H5NH3)3[BiCl6], revealed three anomalies at 152, 191 and 299 K. The structure of the salt was determined at 200 and 315 K, below and above the high-temperature phase transition at 299 K. In both phases the crystals are monoclinic. At 200 K the space group is C2/c whereas at 315 K it is C2/m. The structures, at both temperatures, are composed of [BiCl6]3− octahedra and allylammonium cations. The organic and inorganic moieties are attracted to each other by a network of the N-H. . .Cl hydrogen bonds. The relationship between corresponding parameters of the unit cells has been found. The phase transition at 299 K, of the orde…
Chlorophyll content in senescent Pelargonium graveolens leaves
2019
Pelargonium graveolens należy do rodziny Geraniaceae. Roślina ta jest aromatycznym, owłosionym krzewem, sięgającym 1,2 metra wysokości i osiągającym 1 m szerokości. Jej liście są mocno powcinane, miękkie w dotyku i wydzielają intensywny zapach, natomiast kwiaty są małe, zwykle różowe, zebrane w baldachy. Ojczyzną P. graveolens jest Afryka Południowa, ale uprawia się ją obecnie w wielu krajach świata, np. wyspie Reunion, Egipcie, Rosji, Chinach czy Maroko, głównie z przeznaczeniem na produkcję olejku eterycznego. Wykorzystywany jest on w wielu gałęziach przemysłu, m.in. perfumiarstwie, kosmetyce, przemyśle spożywczym czy medycynie. Dane literaturowe pokazują, że o kondycji całej rośliny świa…
Chiroptical Phenomena in Reverse Micelles: The Case of (1R,2S)- Dodecyl (2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium Bromide (DMEB)
2014
(1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) aggregates dispersed in carbon tetrachloride have been investigated by Fourier transform infrared (FT-IR), vibrational circular dichroism (VCD) and 1H nuclear magnetic resonance (NMR) spectroscopy at various surfactant concentration and water-to-surfactant molar ratio. Experimental data indicate that, even at the lowest investigated concentration and in absence of added water, DMEBmolecules associate in supramolecular assemblies. At higherDMEBconcentration the aggregates can confine watermolecules,making it plausible to think thatDMEB form reverse micelles and that watermolecules are quite uniformly distributed…
On the synthesis of functionalized porphyrins and porphyrin conjugates via β-aminoporphyrins
2016
International audience; The synthesis of functionalized porphyrins and their conjugates from meso-tetraarylporphyrins through the acylation and the oxidation of beta-aminoporphyrins was investigated. 2,3-Dioxochlorins were prepared by the oxidation of a variety of beta-aminoporphyrins and subsequently used in a condensation reaction with functionalized aromatic aldehydes and ammonium acetate to form beta-functionalized porphyrins bearing a fused imidazole ring. Under optimized experimental conditions both reactions tolerate various functional groups and afford the products in an appropriate overall yield. The mildness and usefulness of this methodology are illustrated by several examples in…
Crystal structure of the bis(cyclohexylammonium) succinate succinic acid salt adduct
2015
The title salt adduct comprises two cyclohexylammonium cations, one succinate anion and one molecule of succinic acid, linked together through intermolecular hydrogen-bonding interactions giving a two-dimensional layer-like self-assembly lying parallel to (010).
Crystal structure of dimethylammonium hydrogen oxalate hemi(oxalic acid)
2015
The title salt consists of a dimethylammonium cation (Me2NH2 +), an hydrogenoxalate anion (HC2O4 −), and half a molecule of oxalic acid (H2C2O4) situated about an inversion center. They are linked together through intermolecular hydrogen bonds, forming a two-dimensional bilayer-like self-assembly.
Crystal structure of bis(cyclohexylammonium) diphenyldioxalatostannate(IV)
2015
In the title salt, (CyNH3)2[Sn(Ph2)(C2O4)2] (Cy is cyclohexyl and Ph is phenyl), the SnPh2 moiety is chelated by two oxalate anions, leading to a cis arrangement within the distorted octahedral coordination sphere of the SnIV atom.
Selective formation of a unique diphosphonium-diphosphine from a tetraphosphine double protonation induced by zirconium salts
2008
A mixed ferrocenyl diphosphonium-diphosphine cation, associated with two [ZrCl(5).thf](-) anions, is obtained from a ferrocenyl tetraphosphine, as a unique didentate ionic metalloligand in a perfectly selective reaction induced by ZrCl(4) in THF.