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In atmospheric chemistry, the most common scavenger is the hydroxyl radical, a short-lived radical produced photolytically in the atmosphere. It is the most important oxidant for carbon monoxide, methane and other hydrocarbons, sulfur dioxide, hydrogen sulfide, and most of other contaminants, removing them from the atmosphere.
Scavenger resins are polymers (resins) with bound functional groups that react with specific by-products, impurities, or excess reagents produced in a reaction. Polymer-bound functional groups permit the use of many different scavengers, as the functional groups are confined within a resin or are simply bound to the solid support of a bead.
Hydrogen peroxide (H 2 O 2) can be used as HOCl scavenger whose byproducts do not interfere in the Pinnick oxidation reaction: HOCl + H 2 O 2 → HCl + O 2 + H 2 O In a weakly acidic condition, fairly concentrated (35%) H 2 O 2 solution undergoes a rapid oxidative reaction with no competitive reduction reaction of HClO 2 to form HOCl.
It is a volatile oxygen scavenger [2] [3] and reacts in a ratio of 2.8/1 DEHA/O2. It is employed in high pressure (>70 bar) boiler systems due to a very low rate of reaction at low temperatures and pressures. Due to its volatility, it acts as an oxygen scavenger throughout the entire boiler system due to steam carryover.
DIPEA is a sterically hindered organic base that is commonly employed as a proton scavenger. Thus, like 2,2,6,6-tetramethylpiperidine and triethylamine, DIPEA is a good base but a poor nucleophile, DIPEA has low solubility in water, which makes it very easily recovered in commercial processes, a combination of properties that makes it a useful organic reagent.
In peptide synthesis, TIPS is used as a scavenger for peptide groups being removed from the peptide sequence at the global deprotection. TIPS is able to scavenge carbocations formed in the deprotection of a peptide as it can act as a hydride donor in acidic conditions. [ 1 ]
1,2-Ethanedithiol has been used as a scavenger in peptide cleavage synthesis. [citation needed] Like 1,3-propanedithiol, 1,2-ethanedithiol readily forms metal thiolate complexes. Illustrative is the synthesis of the derivative diiron ethanedithiolate hexacarbonyl upon reaction with triiron dodecacarbonyl: [5]
The first patent for an oxygen scavenger used an alkaline solution of pyrogallic acid in an air-tight vessel. [7] [8] Modern scavenger sachets use a mixture of iron powder and sodium chloride. [8] Often activated carbon is also included as it adsorbs some other gases and many organic molecules, further preserving products and removing odors.