Carboxylic acids types

On cation exchangers (sulfonic acid-type and carboxylic acid-type), a value of = 0.0089 cm. i was observed, corresponding to the hydrated Mn(H20)6++. The effect of axial symmetry (D 9 0) was observed as evidenced by a fine structure in the hyperfine lines. A value of D however was not determined. The EPR spectrum of Mn++ on an anion exchanger studied consisted of a single unresolved broad line. A smaller A value and larger... 

Somewhat smaller < -factors and larger hfs intervals were exhibited by charcoal, zeolite, and a carboxylic acid-type exchange resin, indicating more covalent character in the metal-adsorbent bond. 

Weak cation exchange resins (carboxylic acid type) have been widely employed for the isolation and detection of marine PSP s. However, the less basic gonyautoxins (GTX s) tended to elute with the solvent front with these resins — especially when very crude... 

Carboxylic acid-type Weak acid cation exchangers Amberlite IRC-50 Bio-Rex 70 Che lex 100 Duolite 436 Permutit C Permutits H and H-70 (Rohm and Haas, USA) (Bio-Rad, USA) (Bio-Rad, USA) (Dia-Prosim Ltd) (Permutit AG, Germany) (Permutit Co, USA)... 

Suspension polymerization also is used When acrylic monomers or their mixtures with other monomers are polymerized while suspended (usually in aqueous system), the polymeric product is obtained m the form of small beads, sometimes called pearls or granules. Bead polymers are the basis of the production of molding powders and denture materials. Polymers derived from acrylic or methacrylic acid furnish exchange resins of the carboxylic acid type. Solutions in organic solvents furnish lacquers, coatings and cements, while water-soluble hydrolysates are used as thickeners, adhesives, and sizes. 

Chlorophenoxy carboxylic acid type Cereal, berries Pesticide methylated, then GC-MS [136]... 

For the styrene-butadiene-methacrylic acid copolymers, meth-acrylic acid was also found in the serum, on the particle surface, and buried inside the particles. At 23% degree of neutralization, less methacrylic acid was found in the serum and on the particle surface than with acrylic acid, i.e., more was buried inside the particle. At 3.0% methacrylic acid, the amount incorporated into the particle was fairly constant, independent of the degree of neutralization. The different distributions of methacrylic and acrylic acids were explained by their different distributions between the monomer-polymer and aqueous phases. Thus these characterization results show the effect of vinyl carboxylic acid type and concentration on the loci of the carboxyl groups. Similar correlations could be made with other systems. 

To obtain the [l,2,4]triazolo[4,3- ]isoquinoline series it was not possible to displace the halogen atom of 3-chloroisoquinoline with hydrazine. However, 3-hydrazinoisoquinoline 2-oxide could be prepared from the corresponding 3-chloro 2-oxide, and it could be selectively reduced by titanium trichloride to 3-hydrazinoisoquinoline, a relatively unstable compound (78JHC463). This hydrazino derivative was unresponsive to the usual carboxylic acid type ring closures generally used to make fused [4,3-x] systems. The desired products (299) could be obtained by cyclodehydration of the monoacylhydrazino compounds (300) with polyphosphoric acid. These derivatives (299) were, however, unstable and had to be characterized as their perchlorate salts (301 Scheme 32) (78JHC463) to eliminate the o-quinoid structure. 

Thus, even with conventional resins of the sulfonic and carboxylic acid type, it is possible to obtain selective removal of heavy metal ions from... 

This method only requires the experimentally determined molecular weight, Mn, and solution pH. Wilson and Weber (1977) have proposed a method of correcting for dissociation which assumes that fulvic acid is comprised of two types of carboxylic acid groups. This correction method uses Mn, solution pH, and the experimentally determined equilibrium constants for the two carboxylic acid types. Reuter and Perdue (1981) critically discuss the methods of Hansen and Schnitzer (1969) and Wilson and Weber (1977), and propose a rigorous method of their own that requires knowledge of the instrument readout and pH. This method makes no assumptions about the... 

Carboxylic acid-type Strong Base, anion exchangers... 

The water content of carboxylic-acid-type membranes... 

After fabrication, the ester type films are hydrolyzed in a caustic solution to be converted to carboxylic acid type membranes. Figure 6 shows the change of infrared spectrum by hydrolysis of the ester type film in 25 wt% caustic solution at 90°C for 16 hrs. Complete hydrolysis is indicated by the fact that the absorption at 1780 cm l due to Vc=0 (-COOCH3) is wholly shifted to 1680 cm l of vc=0 (-COONa). 

Mixed liquid ion exchangers of the free-base amine and carboxylic acid type dissolved in a solvent of low polarity proved to be excellent extractants for alkaline earth and transition metal salts from aqueous solutions. 

Swan and Waggott (257), on the basis of their various experimental results, suggested that autooxidative dopa-melanin consists in the main of four types of units 10% of uncyclised units, which are diphenolic (3), 10% of indoline-carboxylic acid type (4), 65% of indole type (5), and 15% of pyrrole type (6). Moreover, of the units of types 4 and 5 taken together, one half are quinonoid and the other half are diphenolic 0.5 H2O was included per average polymer unit. 

A range of tetrahydro-9f/-xanthen-9-ones arise from photo-induced C-O bond formation of 2-methoxyaryl 2-chlorocyclohex-l-enyl ketones and related compounds (14CC5254). Some examples of tetrahydro-9ff-xanthen-9-ones were obtained as diastereomeric mixtures of cis- and traws-isomers through a 4-DMAP-mediated tandem addition reaction of l-(2-hydroxyaryl)alkynones bearing an aldehyde function (Scheme 76) (140L1642). A Robinson annulation of a P-keto ester and methyl vinyl ketone mediated by tin(lV) chloride afforded a tetrahydro-9H-xanthen-9-one-l-carboxylic acid-type compound (14JOC10689). 

Several studies have addressed how car-boxylated Ru complexes interact with Ti02 surface [303, 378, 380-382, 385], In most vibrational studies, an asymmetric C—O stretch consistent with carboxylate binding modes (bidentate or bridging) has been reported [378, 380, 385]. Evidence for ester linkages and H-bonded network have also been reported [303, 376, 382]. Qu and Meyer [378] demonstrated that high surface proton concentrations favor carboxylic acid type linkage where low proton concentrations favor carboxylate type binding modes for complexes. Possible modes of coordination of the... 

Numerous tyrosine hydroxylase inhibitors, chiefly of the phenylalkyl carboxylic acid type, have been described [101,128, 138, 139, 200, 257]. One of the most potent inhibitors in vitro, 3-iodotyrosine, proved inactive in man, probably because it is rapidly dehalogenated in vivo [72]. H22/54 has been found to be one of the most effective tyrosine hydroxylase inhibitors with catechol structure [44, 257]. The pyrroloisoxazole CL-65,263 and its derivatives represent a new type of tyrosine hydroxylase inhibitor [89, 243]. They lower blood pressure and cause... 

Figure 4.9 Representative schematic synthesis process of carboxylic acid-type anionic waterborne polyurethane.

Other scales, such as calcium sulfate (CaSO and barium sulfate (BaSO ) are only slightly soluble in acid. Both are soluble in complexing agents such as EDTA and other carboxylic acid-type chelating agents. Barite can be very hard and thus chemically impenetrable, or it can be fine and soft, thereby enabling mechanical removal or partial chemical removal. Barite sometimes occurs in mixed-scale deposits, wherein an acid-soluble portion (e.g., calcium carbonate) can be removed, along with subsequent physical removal of the barite portion. 

Chem. Descrip. Special carboxylic acid type surfactants Ionic Nature Anionic... 

Amphoterics of the usual carboxylic acid type are readily analyzed by reversed-phase HPLC, which separates them mainly according to alkyl chain length (Table 16). The pH of the mobile phase is controlled as well as the polarity to give proper resolution... 

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