Carboxylates basic

Beryllium, bis(trifluoroacetylacetone)-gas chromatography, 1,560 Beryllium acetate basic, 2, 304 complexes, 3, 8 Beryllium borohydride ammine complexes, 3, 8 Beryllium carboxylates basic, 3, 31... 

A polymeric chain structure is frequently observed for zinc carboxylates. Basic zinc carboxylates form a common tetrameric species, and altering conditions can result in an interconversion between the basic and regular carboxylates.369 Mass spectrometry studies have been carried out... 

As chlorine substitutes for hydrogen in the methyl group of the acetate anion, the carboxylate basicity decreases (i.e., pKa decreases). The thermodynamic data for the Eu(III) and Am(III) complexes and the ligand pKa values are listed in Table II. Data for 3-chloropropionate (16) are also included. 

The light stability of a non-specifically UV stabilized PVC formulation is determined by its thermal stabilization. The thermal stabilizers have a sustained influence on UV stability, in particular when other compounds (e.g., phosphites) are added to the mixture. The following list of thermal stabilizers is compiled in the order of their positive influence on UV stability in PVC organotin maleates > Ba/ Cd carboxylates > basic lead phosphites > organotin mercaptides > Ca/Zn carb-oxylates > aminocrotonic acid esters > basic lead sulfates [86]. 

Be40(02CCH3)e. The acetate is typical of the basic beryllium carboxylates (Be(OH)2 plus ethanoic acid). The structures have O at the centre of a tetrahedron of Be with carb-oxylate spanning each edge of the tetrahedron. Be(02CCH3)2 is formed from BeCl2 and glacial ethanoic acid. 

Physical Properties. Glycine is a colourless crystalline solid soluble in water. Owing to the almost equal opposing effects of the amino and the carboxylic groups. its aqueous solution is almost neutral (actually, slightly acidic to phenolphthalein) and glycine is therefore known as a neutral ampholyte. f It exhibits both acidic and basic properties. 

Various basic substances, such as aromatic amines (naphthyl-amines dissolve with difficulty in dil. HCl, diphenylamine only in cone. HCl, triphenylamine insoluble) nitro-anilines some amino-carboxylic acids. 

The presence of certain substituents e.g., the amino group) may markedly affect the solubibty and other properties of the sulphonic acid or carboxylic acid. Thus such sulphonic acids as the aminobenzenesul-phonic acids, pyridine- and quinoline-sulphonic acids exist in the form of inner salts or zwitter-ions that result from the interaction of the basic amino group and the acidic sulphonic acid. Sulphanilic acid, for example, is more accurately represented by formula (I) than by formula (II) ... 

Carboxylic adds are obtained from aryl iodides by the reaction of chloroform under basic conditions without using CO[336],... 

As long as the nucleophilic atom is the same the more basic the nucleophile the more reactive it is An alkoxide ion (RO ) is more basic and more nucleophilic than a carboxylate ion (RC02 )... 

Section 19 5 Although carboxylic acids dissociate to only a small extent in water they are deprotonated almost completely m basic solution... 

Ester hydrolysis in base is called saponification, which means soap making Over 2000 years ago the Phoenicians made soap by heating animal fat with wood ashes Animal fat is rich m glycerol triesters and wood ashes are a source of potassium car bonate Basic hydrolysis of the fats produced a mixture of long chain carboxylic acids as their potassium salts... 

In base the tetrahedral intermediate is formed m a manner analogous to that pro posed for ester saponification Steps 1 and 2 m Figure 20 8 show the formation of the tetrahedral intermediate m the basic hydrolysis of amides In step 3 the basic ammo group of the tetrahedral intermediate abstracts a proton from water and m step 4 the derived ammonium ion dissociates Conversion of the carboxylic acid to its corresponding carboxylate anion m step 5 completes the process and renders the overall reaction irreversible... 

Section 20 11 Ester hydrolysis m basic solution is called saponification and proceeds through the same tetrahedral intermediate (Figure 20 5) as m acid catalyzed hydrolysis Unlike acid catalyzed hydrolysis saponification is irreversible because the carboxylic acid is deprotonated under the reac tion conditions... 

Section 20 19 The hydrolysis of nitriles to carboxylic acids is irreversible m both acidic and basic solution... 

Phenols that bear strongly electron withdrawing substituents usually give low yields of carboxylated products their derived phenoxide anions are less basic and the equilibrium constants for their carboxylation are smaller... 

Saponification (Section 20 11) Hydrolysis of esters in basic solution The products are an alcohol and a carboxylate salt The term means soap making and denves from the process whereby animal fats were converted to soap by heating with wood ashes... 

The kinds of vinyl monomers which undergo anionic polymerization are those with electron-withdrawing substituents such as the nitrile, carboxyl, and phenyl groups. We represent the catalysts as AB in this discussion these are substances which break into a cation (A ) and an anion (B ) under the conditions of the reaction. In anionic polymerization it is the basic anion which adds across the double bond of the monomer to form the active center for polymerization ... 

Hafnium Carbonate. Basic hafnium carbonate [124563-80-0], Hf2(0H)4C02 XH20, is prepared as a wet paste by reaction of a slurry of basic hafnium sulfate [139290-14-5], Hf 02(S0 2 XH20, and sodium carbonate, then filtering. The basic carbonate has a short shelf life and is preferably prepared as needed. It is a starting material for the preparation of various hafnium carboxylates. 

Resorcinol carboxylation with carbon dioxide leads to a mixture of 2,4-dihydroxyben2oic acid [89-86-1] (26) and 2,6-dihydroxyben2oic acid [303-07-1] (27) (116). The condensation of resorcinol with chloroform under basic conditions, in the presence of cyclodextrins, leads exclusively to 2,4-dihydroxyben2aldehyde [95-01-2] (28) (117). Finally, the synthesis of l,3-bis(2-hydroxyethoxy)ben2ene [102-40-9] (29) has been described with ethylene glycol carbonate in basic medium (118), in the presence of phosphines (119). Ethylene oxide, instead of ethyl glycol carbonate, can also be used (120). 

Because lactic acid has both hydroxyl and carboxyl functional groups, it undergoes iatramolecular or self-esterificatioa and forms linear polyesters, lactoyUactic acid (4) and higher poly(lactic acid)s, or the cycUc dimer 3,6-dimethyl-/)-dioxane-2,5-dione [95-96-5] (dilactide) (5). Whereas the linear polyesters, lactoyUactic acid and poly(lactic acid)s, are produced under typical condensation conditions such as by removal of water ia the preseace of acidic catalysts, the formation of dilactide with high yield and selectivity requires the use of special catalysts which are primarily weakly basic. The use of tin and ziac oxides and organostaimates and -titanates has been reported (6,21,22). 

Functionalization. Copolymers do not have the abiHty to exchange ions. Such properties are imparted by chemically bonding acidic or basic functional groups to the aromatic rings of styrenic copolymers, or by modifying the carboxyl groups of the acryHc copolymers. There does not appear to be a continuous functionalization process on a commercial scale. 

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