Search results for "ammonium salt"

showing 6 items of 6 documents

Crystal structure of 1-hy­droxy-2,2,6,6-tetra­methyl­piperidin-1-ium tri­fluoro­methane­sulfonate

2015

In the cation of the title salt, C9H20NO+·CF3O3S−, the six-membered heterocyclic ring displays a chair conformation. In the crystal, centrosymmetric pairs of cations and anions are linked by N—H...O and O—H...O hydrogen bonds to form rings with aR44(14) graph-set motif.

chemistry.chemical_classificationcrystal structurebiologyHydrogen bondStereochemistryCyclohexane conformationSalt (chemistry)Methane sulfonateGeneral ChemistryCrystal structureCondensed Matter Physicsbiology.organism_classificationRing (chemistry)hydrogen bondingMedicinal chemistryData ReportsCrystallcsh:Chemistrychemistrylcsh:QD1-999triflateTetraammonium saltGeneral Materials ScienceTEMPOActa Crystallographica Section E: Crystallographic Communications
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Dual-stimuli pseudorotaxane switches under kinetic control

2021

A series of dumbbell-shaped sec-ammonium salts with bulky (pseudo)stoppers (‘speed bumps’) were tested for their ability to form pseudorotaxanes with a redox-switchable, tetrathiafulvalene (TTF)-decorated [24]crown-8 ether. Depending on the size of the pseudostoppers, fast (less than ten minutes), slow (hours to days) and very slow (no pseudorotaxanes observed) threading has been observed. NMR spectroscopy as well as tandem mass spectrometry indicate the formation of non-threaded face-to-face complexes prior to pseudorotaxanes formation. Both isomers can be distinguished by their substantially different stability in collision-induced dissociation (CID) experiments. Two external stimuli affe…

Steric effectsMechanical bond010405 organic chemistryOrganic ChemistryEtherNuclear magnetic resonance spectroscopy547010402 general chemistry01 natural sciencesDissociation (chemistry)pseudostoppers0104 chemical scienceschemistry.chemical_compoundCrystallographyDeprotonationchemistrysec-ammonium salts500 Naturwissenschaften und Mathematik::540 Chemie::547 Organische ChemieMoietyTetrathiafulvalenepseudorotaxanes
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Protonation of Carbonate in Aqueous Tetraalkylammonium Salts at 25°C.

2006

Protonation constants of carbonate were determined in tetramethylammonium chloride (Me4NClaq 0.1≤I/mol kg−1 ≤4) and tetraethylammonium iodide (Et4NIaq 0.1≤I/mol kg−1 ≤1) by potentiometric ([H+]-glass electrode) measurements. Dependence of protonation constants on ionic strength was taken into account by modified specific ion interaction theory (SIT) and by Pitzer models. Literature data on the protonation of carbonate in NaClaq (0.1≤I/mol kg−1 ≤6) were also critically analysed. Both protonation constants of carbonate follow the trend Et4NI>Me4NCl > NaCl. An ion pair formation model designed to take into account the different protonation behaviours of carbonate in different supporting electr…

Aqueous solutionProtonation of carbonateSpecific ion interaction theory (SIT)Ion pair formation modelChemistryInorganic chemistryTetraalkylammonium saltProtonationDependence on ionic strengthElectrolyteIon pairsAnalytical Chemistrychemistry.chemical_compoundIonic strengthTetramethylammonium chlorideAqueous solutionPitzer equationsCarbonateSettore CHIM/01 - Chimica AnaliticaProtonation of carbonate; Dependence on ionic strength; Aqueous solution; Tetraalkylammonium salts; Ion pair formation model; Specific ion interaction theory (SIT); Pitzer equationPitzer equation
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Effect of quaternary ammonium salts on spectral properties of zinc octacarboxyphthalocyanine

2020

Abstract The paper presents results of the research on the influence of quaternary ammonium salts on UV–vis absorption and emission spectra of zinc octacarboxyphthalocyanine (ZnPcOC). Quaternary ammonium salts which show biological activity play a crucial role. In ZnPcOC solutions with a proper concentration of tetrabutylammonium salts (TBAX), a strong bathochromic shift band (λmax = 760 nm – “R” band) showing red fluorescence appears in time. The presence of tetrabutylammonium salt causes pH increase and, consequently, a gradual dissociation of carboxyl groups in ZnPcOC molecule. It seems that –COO— anions present in the ZnPcOC complex can interact with tetraalkylammonium cations, causing …

010405 organic chemistryChemistryOrganic ChemistryInorganic chemistrySpectral propertieschemistry.chemical_elementZincUV–Vis spectraQuaternary ammonium salts010402 general chemistry01 natural sciencesFluorescenceDissociation (chemistry)Fluorescence0104 chemical sciencesAnalytical ChemistryZinc octacarboxyphthalocyanineInorganic Chemistrychemistry.chemical_compoundPDTBathochromic shiftMoleculeAmmoniumEmission spectrumSpectroscopyJournal of Molecular Structure
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Synthesis of cyanoacetic acid by carbon dioxide and electrogenerated acetonitrile anion in undivided cells equipped with sacrificial anodes

2008

The electrochemical synthesis of cyanoacetic acid was performed by cathodic reduction of tetraalkylammonium salts (R4NX) in acetonitrile in undivided cells equipped with sacrificial anodes with concomitant or subsequent addition of carbon dioxide. These syntheses avoid the use of dangerous reagents, yield cyanoacetic acid in moderate faradic yields and confirm that the cathodic reduction of tetraalkylammonium salts in the presence of acetonitrile leads to the formation of the anion CNCH2-.

chemistry.chemical_classificationCHLOROACETONITRILE electrocarboxylationNitrileSupporting electrolyteGalvanic anodecathodic reduction of alkyl ammonium saltsGeneral Chemical EngineeringCarboxylic acidInorganic chemistrycarbon dioxideSettore ING-IND/27 - Chimica Industriale E TecnologicaElectrochemistryAnalytical Chemistrychemistry.chemical_compoundsupporting electrolyteSettore ING-IND/22 - Scienza E Tecnologia Dei Materialialkyl ammonium saltCyanoacetic acidchemistryReagentElectrochemistrycyanoacetic acidAcetonitrilesacrificial anodeJournal of Electroanalytical Chemistry
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Encapsulation of secondary and tertiary ammonium salts by resorcinarenes and pyrogallarenes: the effect of size and charge concentration

2015

The binding of different categories of alkyl ammonium (secondary and tertiary mono- and di-ammonium) salts with resorcinarenes and a pyrogallarene through weak interactions was analysed in all phases. 1H NMR spectroscopy and electrospray ionisation mass spectrometry were utilized in analysing the complexes in solution and in the gas phase, respectively. The 1H NMR titration studies in methanol-d4 reveal that the association constants for the 1:1 complexes vary according to the electronic properties of the hosts as well as the size, geometric orientation and charge concentration of the guest cations with binding constants of up to 950 M−1 in some cases. Mass spectrometry reveals 1:1 monomeri…

chemistry.chemical_classificationElectrosprayHydrogen bondAnalytical chemistryammonium saltsGeneral ChemistryCrystal structureCondensed Matter PhysicsMass spectrometrychemistrychemistry.chemical_compoundCrystallographyMonomerchemistryProton NMRGeneral Materials ScienceTitrationta116AlkylCrystEngComm
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