Results 241 to 250 of about 51,809 (295)
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Separation of Pyridine Mono-Carboxylic Acids on Paper Chromatograms
Nature, 1956CHEMICAL methods using cyanogen bromide and aromatic amines1–3 (Konig reaction) and an acid-indicator4 for the detection of pyridine carboxylic acids on paper chromatograms have been reported. But the toxic character of cyanogen bromide causes difficulty; and it has been observed that good spots with acid-indicator are often not produced, particularly ...
JIBAN K. CHAKRABARTI, AJOY K. GUHA
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Complexes of Carboxylic Acids with Pyridines and Pyridine N-Oxides
HETEROCYCLES, 1994A brief survey is given of dielectric, spectroscopic, thermodynamic, colligative and conductivity properties of non-aqueous solutions of carboxylic acid complexes with pyridines and pyridine N-oxides. Selected problems of solid state are also reviewed.
Miroslaw Szafran, Zofia Dega-Szafran
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Thermochemistry of aqueous pyridine-3-carboxylic acid (nicotinic acid)
The Journal of Chemical Thermodynamics, 2011Abstract The molar enthalpy of solution of solid nicotinic acid (NA) at T = 298.15 K, to give an aqueous solution of molality m = 3.748 · 10−3 mol · kg−1, was determined as Δ sol H m = (19,927 ± 48) J · mol−1, by solution calorimetry.
Elsa M. Gonçalves +2 more
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ChemInform Abstract: HALOGENATED PYRIDINES. IV. NUCLEAR CHLORINATED PYRIDINE‐3‐CARBOXYLIC ACIDS
Chemischer Informationsdienst, 1976AbstractDie durch Kupfersulfat/Quecksilbernitrat katalysierte HNO3‐Oxidation der halogenierten 3‐Chlormethyl‐pyridine (Ia) bzw. (Ib) führt zu den Nicotinsäuren (IIa) bzw. (IIb), die in 66 bzw. 34%iger Ausbeute auch durch Oxidation von (Ia) bzw. (Ib) mit wäßrigem KMnO4 bei 95°C zugänglich sind; weiterhin lassen sich (II) auch durch Hydrolyse der ...
FRANCIS MUTTERER, CLAUS D. WEIS
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Amphoteric ion-exchangers based on pyridine carboxylic acids
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1970Amphoteric ion-exchangers have been prepared by the reaction of styrene and divinylbenzene copolymers of conventional and macroporous structure with pyridine carboxylic acids.
E. E. Ergozhin +3 more
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Pyridine-Based Cavitands for Acid and Carboxylate Recognition
Molecular Crystals and Liquid Crystals, 2006The design, syntheses and binding capabilities of two novel cavitand-based receptors are described. Receptor 1, contains a cyclic array of pyridine moieties in its appendages and was synthesized in a single step from the known tetrol: refluxing tetrol with 2-bromomethyl 6-hydroxymethylpyridine under basic conditions. Receptor 2 was obtained by stirring
Nicola Edwards +3 more
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HYDROGEN BONDING OF PYRIDINE-CARBOXYLIC ACIDS IN SOLIDS
Chemistry Letters, 1973Abstract The nature of the hydrogen bonds in pyridine-carboxylic acids is studied theoretically. There is an interesting relationship between O···N and N···H distances in the systems. The relation can be reasonably explained by the consideration of the charge transfer interactions.
Fusao Takusagawa +2 more
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The Journal of Physical Chemistry A, 2016
The rotational spectra of four isotopologues of the 1:1 complex between formic acid and pyridine show that the two units are linked together through a "classical" (OH···N) and a weak (CH···O) hydrogen bond. The molecular system appears quite rigid and no effects of the internal motions have been observed in the spectrum.
Spada, Lorenzo +3 more
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The rotational spectra of four isotopologues of the 1:1 complex between formic acid and pyridine show that the two units are linked together through a "classical" (OH···N) and a weak (CH···O) hydrogen bond. The molecular system appears quite rigid and no effects of the internal motions have been observed in the spectrum.
Spada, Lorenzo +3 more
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Applied Microbiology and Biotechnology, 2000
We have previously described the isolation of the new bacterial species, Ralstonia/Burkholderia sp. strain DSM 6920, which grows with 6-methylnicotinate and regioselectively hydroxylates this substrate in the C2 position by the action of 6-methylnicotinate-2-oxidoreductase to yield 2-hydroxy-6-methylnicotinate (Tinschert et al. 1997).
A, Tinschert +3 more
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We have previously described the isolation of the new bacterial species, Ralstonia/Burkholderia sp. strain DSM 6920, which grows with 6-methylnicotinate and regioselectively hydroxylates this substrate in the C2 position by the action of 6-methylnicotinate-2-oxidoreductase to yield 2-hydroxy-6-methylnicotinate (Tinschert et al. 1997).
A, Tinschert +3 more
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Carboxylic acid–pyridine supramolecular heterocatemer in a co-crystal
Journal of Molecular Structure, 2008Abstract Robustness of carboxylic acid–pyridine supramolecular heterosynthon was examined in three 1:2 binary co-crystals of 4,4′-bipyridine with monocarboxylic acids, (4,4′-bipyridine)·( dl -hydroxyphenylacetic acid)2, 1; (4,4′-bipyridine)0.5·(4-bromonaphthalene-1-carboxylic acid), 2 and (4,4′-bipyridine)0.5·(4-methylbenzoic acid), 3.
P. Sudhakar +7 more
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