Maleic, Fumaric, and Succinic Acids

Note that the ratio is almost the same for the two solvents. These ratios are, however, far from the inverse ratio of the proton-proton distances, which is about 

The case of succinic acid cannot be discussed in terms of Coulombic interactions alone. Here, conformational changes induced by the binding process can contribute significantly to the correlation. Note also that g(l, 1) [or W(l, 1)] of succinic acid is not an average of the correlations in maleic and fiimaric acids. This could be partially due to the configurational changes in the succinic acid, induced by the binding process. We shall discuss below a simple two-state model for succinic acid, and a continuous model in the next subsection. 

Experimental Values of (1,1) and leCl, 1) (in kcal/mol) for Maleic, Fumaric, and Succinic Acid. Below Are Some Computed Values for the Model 

For the analogues of maleic and fumaric acid, we choose the C -C distance to be 1.34 A and fix the angle ( = 0 and ( ) = 7t, respectively. If it is assumed that for these molecules the proton-proton correlation is purely electrostatic, then we can write 

One can easily adjust the values of the dielectric constants D(, and Dj to obtain the experimental values of W, as in Table 4.4. With a choice of = 19.6 and Dj. = 51.0 for water, and D. = 12.5 and Dj. = 31.8 for 50% water-ethanol, we obtain the experimental values of W. We now compute the total correlation function for the two-state model for succinic acid. Here the correlation cannot be computed as an average correlation of the two configurations (see Section 4.5). The total correlation of the equilibrated two-state model is 

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Table 4.4 shows the values of the proton-proton correlation for the three dicarboxylic acids maleic, fumaric, and succinic acids (Fig. 4.26). All the values of W(l, 1) are positive, i.e., negative cooperativity. Since the configuration of the first two acids is nearly rigid, one can expect that the larger the proton-proton distance, the weaker the cooperativity. Indeed, the ratio of W(l, 1) for the first two... 

Figure 4.26. The structural formulas for maleic, fumaric, and succinic acids.

Mares et al. [52] recently concluded that hydrogen-ion catalysis during this esterification was not likely and that catalysis by undissociated acid occurred together with a reaction in which, kinetically at least, no form of catalysis was involved. On the other hand, Vansco-Szmercsanyi et al. [53] concluded that polyesterification of maleic, fumaric and succinic acids with ethylene glycol or 1,2-propylene glycol was catalysed by protons. Much work clearly remains to be done on defining the detailed mechanism of catalysis by the acidic species during esterifications. 

Succinic anhydride [108-30-5] (3,4-dihydro-2,5-furandione butanedioic anhydride tetrahydro-2,5-dioxofuran 2,5-diketotetrahydrofuran succinyl oxide), C H O, was first obtained by dehydration of succinic acid. In the 1990s anhydride is produced by hydrogenation of maleic anhydride and the acid by hydration of the anhydride, by hydrogenation of aqueous solutions of maleic acid, or as a by-product in the manufacture of adipic acid (qv) (see Maleic ANHYDRIDE, MALEIC ACID, AND FUMARIC ACID). 

The peak at 17.34 min is 50 pg ml mesaconic acid which was added as a possible internal standard, but it proved unsuitable because of an unknown peak eluting at 16.78 minutes seen when analysing silage juice without added internal standard oxalic acid suffered from the same problem. We still need a suitable internal standard for this column, thus further use was suspended. Other failed compounds included adipic acid, fumaric acid, D-glucuronic acid, glutaric acid, glycolic acid, 3-hydroxybutanone, itaconic acid, malic acid, maleic acid, malonic acid, pimelic acid and succinic acid. 

Woodman et al. (1968) developed a gravimetric method (by means of the sodium salts) for determining the total carboxylic acids present in infusions of Santos coffee. This quantity increased with the degree of roasting, a consequence of the destruction of phenolic acids. From the 12 identified acids, eight were said to be reported for the first time in coffee 2-furoic acid (1.103) (see Section 5.1), mesaconic acid (E.50), fumaric acid (E.47), citraconic acid (E.51), itaconic acid (E.52), lactic acid (E.30), succinic acid (E.44) and maleic acid (E.48). In fact, fumaric, lactic and succinic acids were mentioned by Schormtiller et al. (1961) (see above). 

Colourless prisms m.p. 130 C. Manufactured by treating maleic anhydride with water. It is converted to the anhydride by heating at By prolonged heating at 150 "C or by heating with water under pressure at 200 C, it is converted to the isomeric (trans) fumaric acid. Reduced by hydrogen to succinic acid. Oxidized by alkaline solutions of potassium permanganate to mesotartaric acid. When heated with solutions of sodium hydroxide at 100 C, sodium( )-malate is formed. Used in the preparation of ( )-malic acid and in some polymer formulations. 

Both acids 3deld succinic acid, m.p. 185°, upon catalytic reduction (see Section 111,150), thus establishing their structures. Maleic and fumaric acids are examples of compounds exhibiting cis-trans isomerism (or geometric isomerism). Maleic acid has the cm structure since inter alia it readily 3delds the anhydride (compare Section 111,93). Fumaric acid possesses the trans structure it does not form an anhydride, but when heated to a high temperature gives maleic anhydride. 

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. 

Detailed studies of 1 1 complex formation between and maleic and fumaric acids, which precedes reduction to succinic acid, cis-trans isomerisation and exchange of the double bond hydrogens, are relevant to the complex kinetics (A = substrate)... 

CE is widely used for separation and quantification of organic acids (Stover, 1997). Many CE studies were performed to quantify organic acids in some food matrices (Erazier, 2001 Galli et al., 2003 Klampfl et al., 2000 Lindeberg, 1996). Many small organic acids can be well separated with CE (Boden et al., 2000 Mato et al., 2006a,b Navarrete et al., 2005). Those acids include acetic, citric, fumaric, lactic, maleic, malic, oxalic, pyruvic, succinic, and gluconic acids which can be separated by CE in a short time. 

The aromatic spacer group of the model receptors prevent the formation of intramolecular hydrogen bonds between the opposing carboxyls yet these functions are ideally positioned for intermolecular hydrogen bonds of the sort indicated in 32. The acridine derivatives do indeed form stoichiometric complexes with oxalic, malonic (and C-substituted malonic acids) as well as maleic and phthalic acids, Fumaric, succinic or glutaric acids did not form such complexes. Though protonation appears to be a necessary element in the recognition of these diacids, the receptor has more to... 

The quantity (5) is an average of the direct correlations S. and 5yin a hypothetical system, where the mole fractions of the two configurations are and respectively (see Section 4.5). As such, (S) is bound by and Sj, but y(l, 1) must be larger than unity and is not bound by and In Table 4.4 we see that both the experimental and calculated values of 11 (1,1) are closer to the fumaric rather than the maleic values. One could argue that since the ionized succinic acid would be most of the time in the trans configuration, we should expect that the value of IV for the succinie aeid be closer to the fumaric acid value. The faet that the IV (succinic) is indeed intermediate between IV (maleic) and IV (fumaric) is quite accidental. The value of IV (succinic) is determined by both the negative correlation (5) and the positive correlation y(l, 1). 

Uses. About 60% of the MA produced is used to make unsaturated polyester and aikyd resins, which are formed by reaction of MA with glycols. Polyester resins are used in the fabrication of glass fiber reinforced parts. Applications include boat hulls, automobile body parts, patio furniture, shower stalls, and pipe. Aikyd resins are mostly used in coatings (paint, varnish, lacquers, and enamels). MA also is widely used as a chemical intermediate in the manufacture of plasticizers and dibasic acids (fumaric, maleic, and succinic). About 15% of MA production goes into the manufacture of viscosity index improvers and dispersants used as additives in lube oils. Several agricultural chemicals are based on maleic anhydride, the best known being Malathion. 

Molecular forms that arise as a result of rotation around freely rotatable bonds are known as conformers. Even small molecules can have different conformations in solution. In the two conformations of succinic acid illustrated opposite, the atoms are arranged in a similar way to fumaric acid and maleic acid. Both forms are possible, although conformation 1 is more favorable due to the greater distance between the COOH groups and therefore occurs more frequently. Biologically active mac-... 

The simplest unsaturated dicarboxylic acids are maleic acid and fumaric acid, both of which are cheap, commercially available, materials. They are geometric isomers maleic acid is the (Z) isomer (19), and fumaric acid is the (E) isomer (20). Maleic acid forms an internal anhydride, maleic anhydride (21), which is widely used to form adducts with conjugated dienes (the Diels-Alder reaction, Section 7.6). The formation of the anhydride from maleic acid and the conversion of maleic acid into fumaric acid are described in Expt 5.218. The hydrogenation of maleic acid to succinic acid is of value as a means of evaluating the activity of a catalyst for use in hydrogenations at atmospheric pressure the experimental procedure is given in Section 2.17.1, p. 87. 

Propionic acid, crotonic acid, benzoic acid, succinic acid, maleic and fumaric acid, phthalic acid, camphoric acid, glycollic acid, lactic acid, malic acid, tartaric acid, the oxybenzoic acids, pyroracemic acid, laevulinic acid, dehydracetic acid, and aceto-acetic acid (or its esters). 

Plants. Various acids, e.g., succinic, fumaric, and maleic, are found as metabolites Soil. DT50 c. 11 hr... 

Maleic Acid HOOC—CH = CH—COOH Fumaric Acid S3mthesis from Succinic Acid.—Two isomeric acids are known oi the constitution of di-carboxy ethene, or bulen-di-oic acid. They are named maleic acid and fumaric acid. Their synthesis from succinic acid establishes their constitution. Mono-brom succinic acid when... 

The reverse of these reactions viz., the conversion of maleic and fumaric acids, by the addition of hydrogen bromide, into mono-brom succinic acid by the addition of two bromine atoms, into di-brom succinic acid and also by the addition of two hydrogen atoms, into succinic acid itself all show these same relations of maleic and fumaric acids to succinic acid and its bromine substitution products and establish the constitution of these isomeric di-basic unsaturated acids as given. The two acids may also be prepared from malic acid which is, in fact, the chief method by which they are prepared. This reaction will be considered later when malic acid itself is studied. 

The proof that maleic acid corresponds to the cis formula and fumaric acid to the Irans formula is in the fact that maleic acid readily forms an anhydride while fumaric acid does not. If the two carboxyl groups are on the same side, as in the cis form, the compound would have a tendency to lose water easily while if the two carboxyl groups are on opposite sides, as in the trans form, the compound would not have this tendency to lose water. The space relations of the two carboxyl groups is readily seen if the two compounds are built up by means of tetra-hedral models. It is analogous to that in succinic acid and glutaric acid (p. 281). 

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