COOH acid group

The —COOH acid group reacts with the —NH2 amine group to form an amide. A molecule of... 

Method. An amino-acid such as glycine, NHjCH,COOH, cannot be estimated by direct titration with standard alkali solution, owing to the opposing effects of the basic and the acidic groups. If, however, the amino-acid is first... 

The diacids are characterized by two carboxyHc acid groups attached to a linear or branched hydrocarbon chain. AUphatic, linear dicarboxyhc acids of the general formula HOOC(CH2) COOH, and branched dicarboxyhc acids are the subject of this article. The more common aUphatic diacids (oxaUc, malonic, succinic, and adipic) as weU as the common unsaturated diacids (maleic acid, fumaric acid), the dimer acids (qv), and the aromatic diacids (phthaUc acids) are not discussed here (see Adipic acid Maleic anhydride, maleic acid, and fumaric acid Malonic acid and derivatives Oxalic acid Phthalic acid and OTHERBENZENE-POLYCARBOXYLIC ACIDS SucciNic ACID AND SUCCINIC ANHYDRIDE). The bihinctionahty of the diacids makes them versatile materials, ideally suited for a variety of condensation polymerization reactions. Several diacids are commercially important chemicals that are produced in multimillion kg quantities and find appHcation in a myriad of uses. 

Carboxylic A term describing a specific acidic group (COOH) that contrib- utes cation-exchange ability to some resins. 

We also have to count on variations of the main monomer unit as well. For example, HEMA materials always contain traces of unesterified free carboxylic groups. These acidic groups interact with polycations. As result, retardation is observed until total adsorption of the injected sample. Consequently, polycations can be analyzed on such a material only in acidic eluents, where the dissociation of the — COOH— group is suppressed. 

FIGURE 4.2 The a-COOH and groups of two amino acids can react with the resulting loss of a water molecule to form a covalent amide bond. (Irving Geis.)... 

Hydroxyindoles carrying a side chain containing a free NH2, OH, or COOH functional group are unstable. Therefore, 1-hydroxytryptophan, -tryptamine, and -indole-3-acetic acid have not been prepared yet. 

PROBLEMS For each compound below, determine the configuration of every stereocenter. Then draw the enantiomer of each compound below (the COOH group is a carboxylic acid group). 

Charged and uncharged forms of the ionizable —COOH and —NH3+ weak acid groups exist in solution in protonic equihbrium ... 

Acid Group Selectivity (mole COOH/mole CO to FT)... 

The complex 99mTc(V)-DMSA (64) has been used for a long time for the imaging of renal blood flow and morphology of the kidneys. The exact composition and structure of the agent is still unknown, as is the mechanism of retention. A structure of 64 (where R = COOH) has been proposed with three possible conformations, syn-endo, syn-exo, and anti, of the carboxylic acid groups with respect to the Tc = 0 core (280). 

The surface character of fibres influences their affinity towards various chemical additives by, for example, their adsorption properties and also in their tendency to flocculate. Cellulosic fibres, because of the presence of acidic groups which are introduced during chemical pulping and bleaching, are mildly anionic. These acidic groups may be carboxylic (COOH) or in some cases sulfonic acid (S03H) and they are able to dissociate to leave a net negative... 

In addition to the a-amino and a-carboxyl groups those amino acids with an extra ionizable group will also have a pvalue. Glutamic acid is an example of an amino acid with an extra acidic group (COOH) on the y-carbon, and lysine is an example of an amino acid with an extra amino group on the e-carbon atom. As a result they each have three ionizable groups and three pKa... 

During PBT polymerization, carboxylic acid (COOH) end groups can react with BDO to regenerate hydroxybutyl endgroups and water, by a direct esterification reaction ... 

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