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Pyridine is a toxic, flammable liquid with a strong and unpleasant fishy odour. Its odour threshold of 0.04 to 20 ppm is close to its threshold limit of 5 ppm for adverse effects, [117] thus most (but not all) adults will be able to tell when it is present at harmful levels. Pyridine easily dissolves in water and harms both animals and plants ...
Containing a pyridinium ion, pyridinium chloride has a pK a of approximately 5, slightly more acidic than that of typical amines.This is due to the hybridization of the nitrogen: the nitrogen is sp 2 hybridized and more electronegative than those nitrogens in ammonium cations, which are sp 3 hybridized.
C 5 H 5 N + HCl + CrO 3 → [C 5 H 5 NH][CrO 3 Cl] In one alternative method, formation of toxic chromyl chloride (CrO 2 Cl 2) fumes during the making of the aforementioned solution were minimized by simply changing the order of addition: a cold solution of pyridine in concentrated hydrochloric acid was added to solid chromium trioxide under ...
Octenidine dihydrochloride is active against Gram-positive and Gram-negative bacteria. [5]In vitro suspension tests with 5 minute exposure time have shown that octenidine requires lower effective concentrations than chlorhexidine to kill common bacteria like Staphylococcus aureus, Escherichia coli, Proteus mirabilis and the yeast Candida albicans.
Cetylpyridinium chloride is known to cause tooth staining in approximately 3 percent of users. [14] The Crest brand has noted that this staining is actually an indication that the product is working as intended, as the stains are a result of bacteria dying on the teeth. [15]
Cr(VI)-pyridine and pyridinium reagents have the advantage that they are soluble in organic solvents as are the alcohol substrates. One family of reagents employs the complex CrO 3 (pyridine) 2. [2] Sarett's reagent: a solution of CrO 3 (pyridine) 2 in pyridine. It was popularized for selective oxidation of primary and secondary alcohols to ...
The handling of this chemical may incur notable safety precautions. It is highly recommend that you seek the Material Safety Datasheet for this chemical from a reliable source such as eChemPortal, and follow its directions.
Darzens halogenation is the chemical synthesis of alkyl halides from alcohols via the treatment upon reflux of a large excess of thionyl chloride or thionyl bromide (SOX 2) in the presence of a small amount of a nitrogen base, such as a tertiary amine or pyridine or its corresponding hydrochloride or hydrobromide salt.