1.2- Dihydroxybenzene 3,5-disulfonate

Among several iron chelators used, only o-phenanthroline inhibited the soluble dehydrogenase (42). It was shown by Hateff et al. (42) that incubation of the enzyme with o-phenanthroline results in the loss of labile sulfide, while pretreatment with bathophenanthroline sulfonate, Tiron (1,2-dihydroxybenzene 3,5-disulfonate) or ethylenediamine tetraacetate protects the enzyme against the loss of labile sulfide and inhibition of activity upon subsequent incubation with o-phenanthroline. The unique destructive ability of o-phenanthroline has been demonstrated by these investigators for several iron-sulfur proteins (S5,96). 

Test with disodium 1,2-dihydroxybenzene-3,5-disulfonate (tiron) ... 

The existence of a wide variety of zirconium(IV)-aminopolycarboxylate complexes in solution was established by the potentiometric titration studies of Intorre and Martell.675-677 This work and related solution studies have been reviewed by Larsen.5 Zirconium(IV) forms 1 1 and 1 2 complexes with tetradentate aminopolycarboxylates, 1 1 complexes with hexadentate and octadentate aminopolycarboxylates, and mixed ligand complexes with aminopolycarboxylates and various bidentate ligands, for example 1 1 1 Zr-edta-Tiron and 1 1 2 Zr—nta-Tiron complexes (Tiron = l,2-dihydroxybenzene-3,5-disulfonate). The stoichiometries of these complexes are consistent with the tendency of zirconium to achieve a coordination number of eight. 

Several metals, including iron, copper and tin, can fog emulsions. Emulsions can be partly stabilized by sequestering these metallic species with suitable ligands. Catechol derivatives are reported to be helpful in preventing fog from this source. Examples include 1,2-dihydroxy-benzene-4-sulfonic acid (sodium salt) and l,2-dihydroxybenzene-3,5-disulfonic acid (disodium salt).37... 

Domingo JL, de la Torre A, Belles M, et al. 1997. Comparative effects of the chelators sodium 4,5-dihydroxybenzene-l,3-disulfonate (tiron) and diethylenetriaminepentaacetic acid (dtpa) on acute uranium nephrotoxicity in rats. Toxicology 118( 1 ) 49-59. 

Zalups RK. 1991. An evaluation of Tiron (Sodium 4,5-dihydroxybenzene-l,3-disulfonate) as arescue agent for the nephropathy induced by uranyl fluoride (U02F2) in rats. Research Communications in Chemical Pathology and Pharmacology. 72(1) 125-128. 

Dihydroxybenzene is prepared industrially by the alkali fusion of benzene-1,3-disulfonic acid. 1,4-Dihydroxybenzene is prepared in large quantities for use as a photographic developer, one process being by the oxidation of aniline with manganese dioxide [manganese(IV) oxide] in sulfuric acid to give benzo-l,4-quinone, which is then reduced to 1,4-dihydroxybenzene (hydroquinone, quinol). 

The benzenedisulfonic acids are of little interest, except that benzene-1,3-disulfonic acid is a source of 1,3-dihydroxybenzene (see Chapter 4). The benzene dicarboxylic acids are more important. Benzene-1,2-dicarboxylic acid (phthalic acid, 8) can be converted into phthalic anhydride (9), which is a typical acid anhydride, reacting with amines and alcohols and also taking part in Friedel-Crafts reactions. Phthalimide (10), produced by reaction of the anhydride with ammonia, is weakly acidic and forms a potassium salt with ethanolic potassium hydroxide. 

Intorre and Martell (237) have also studied the formation of mixed chelate species in which the zirconium 1 1 complex with the hexa-dentate chelating ligands, ethylenediaminetetraacetic acid, iV-hydroxy-ethylethylenediaminetriacetic acid, and m7 s-cyclohexanediaminetetra-acetic acid, are shown to take up one mole of the bidentate ligands, l,2-dihydroxybenzene-3,5-disulfonate l,8-dihydroxynaphthalene-3,6-disulfonate 8-hydroxyquinoline-5-sulfonate, and acetylacetone (except ZrHEDTA), to form 8-coordinate 1 1 1 species. At least for the zir-conium-EDTA-l,2-dihydroxybenzene-3,5-disulfonate species, there is evidence for dimerization (230). Additionally, the Zr EDTA complex reacts with one mole of the bidentate ligands, 5-sulfosalicyclic acid, alizarin sulfonate, citric acid, and lactic acid to form 1 1 1 complexes tartaric acid and pyrophosphate ions form complexes which could not be identified. The zirconium-nitriloacetic acid complex in the presence of two moles of oxalic acid or l,2-dihydroxybenzene-3,5-sulfonate also forms 1 1 1 complexes in solution. 

Formation of zirconium and hafnium complexes with polyhydroxyaromatic compounds in aqueous solution has been studied by potentiometric, spectrophotometric and ion exchange methods. Much of this work has been reviewed by Larsen. A potentiometric and lightscattering study of the zirconium(IV)-Tiron (Tiron = disodium l,2-dihydroxybenzene-3,5-disulfonate) system provides evidence for mixed hydroxo-Tiron chelates at Tiron/Zr " ratios less than 2.5, but at higher Tiron/Zr ratios the unhydrolyzed complexes [Zr2L5] and [ZrL4] (L = tetranegative anion of l,2-dihydroxybenzene-3,5-disulfonic acid) are present. ... 

Disodium-l,2-dihydroxybenzene-3,5-disulfonate (tiron) yields a strong yellow color when reacted with titanium salts in the pH range of 4.3-9.6 [15]. Titanium salts also react with 5- ilf< alicylic acid at pH 3-5 to yield yellow solutions [16]. Other reagents which have found limited use in identification testing are thymol [17], gallic acid [18], and salicylic acid [19]. 

Dibromo-l,2-dihydroxybenzene-3,6-disulfonic acid (CgH OgBr S ) 2,4-Dihydroxy-1-propionylbenzene (2,4-dihydroxypropiophenone)... 

Resorcinol (m-dihydroxybenzene) is of greater commercial importance than catechol. It was first produced by Wilhelm Komer in 1868 by alkali fusion of iodophenol. Current industrial processes for resorcinol production are based either on benzene-m-disulfonic acid, which is converted to the dihydroxy com-... 

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