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In chemistry, work-up refers to the series of manipulations required to isolate and purify the product(s) of a chemical reaction. [1] The term is used colloquially to refer to these manipulations, which may include: deactivating any unreacted reagents by quenching a reaction.
Acid–base extraction is a subclass of liquid–liquid extractions and involves the separation of chemical species from other acidic or basic compounds. [1] It is typically performed during the work-up step following a chemical synthesis to purify crude compounds [2] and results in the product being largely free of acidic or basic impurities.
It is a common observation that when oil and water are poured into the same container, they separate into two phases or layers, because they are immiscible.In general, aqueous (or water-based) solutions, being polar, are immiscible with non-polar organic solvents (cooking oil, chloroform, toluene, hexane etc.) and form a two-phase system.
An aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula . For example, a solution of table salt , also known as sodium chloride (NaCl), in water would be represented as Na + (aq) + Cl − (aq) .
Aqueous samples, lysed cells, or homogenised tissue are mixed with equal volumes of a phenol:chloroform mixture. This mixture is then centrifuged. This mixture is then centrifuged. Because the phenol:chloroform mixture is immiscible with water, the centrifuge will cause two distinct phases to form: an upper aqueous phase, and a lower organic phase.
Grignard reagents or Grignard compounds are chemical compounds with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH 3 and phenylmagnesium bromide (C 6 H 5)−Mg−Br. They are a subclass of the organomagnesium compounds.
In the basic structure of Pd-PEPPSI, R 1 can be a methyl (CH 3, Me), ethyl (C 2 H 5, Et), isopropyl (C 3 H 7, i Pr), isopentyl (C 5 H 11, i Pent), or isoheptyl (C 7 H 15, i Hept) group, and starting from the second in the row the resulting catalysts are thus labeled as PEPPSI-IEt, PEPPSI-IPr, PEPPSI-IPent, and PEPPSI-IHept respectively, with or without "Pd-" added in front. [7]
The nucleophilic lysine residue is commonly targeted site in protein bioconjugation, typically through amine-reactive N-hydroxysuccinimidyl (NHS) esters. [3] To obtain optimal number of deprotonated lysine residues, the pH of the aqueous solution must be below the pKa of the lysine ammonium group, which is around 10.5, so the typical pH of the reaction is about 8 and 9.