Of p-phenylenediamine

It is an important dyestuffs intermediate, being used as a first component in azo-dyes and also as a source of p-phenylenediamine. 

The kinetics of PAA, synthesized from 4,4 -oxydianiline and pyromellitic dianhydride, solid-state imidization both in filler absence and with addition of 2 phr Na+-montmorillonite was studied [1], The nanofiller was treated by solution of P-phenylenediamine in HC1 and then washed by de-ionized water to ensure a complete removal of chloride ions. The conversion (imidization) degree Q was determined as a function of reaction duration t with the aid of Fourier transformation of IR-spectra bands 726 and 1014 cm 1. The samples for FTIR study were obtained by spin-coating of PAA/Na+-montmorillonite mixture solution in N,N-dimethylacetamide on KBr disks, which then were dried in vacuum for 48 h at 303 K. It was shown, that the used in paper [1] method gives exfoliated nanocomposites. The other details of nanocomposites polyimid/Na+-montmorillonite synthesis and study in paper [1] were adduced. The solid-state imidization process was made at four temperatures 7) 423, 473, 503 and 523 K. 

If this cleavage principle is applied to the molecule of aniline black it will be found that from it four molecules of quinone, three molecules of p-phenylenediamine, and one molecule each of aniline and ammonia arise. Since an excess of chromic acid is present, the p-phenylene-diamine is readily dehydrogenated to quinonediimine, which is hydrolytically decomposed into quinone and ammonia. The single molecule of aniline begins the cycle anew. 

Depending on the molar ratio, the reactions of p-phenylenediamines and EMME gave N-(4-aminophenyl)aminomethylenemalonates (167) (86-EUP174832) or l,4-bis(aminomethyIenemalonates) (168) (49JCS1017 86-EUP174832). 

Uses Intermediate for dyes and antioxidants inhibits gum formation in gasoline corrosion inhibiter organic synthesis (preparation of p-phenylenediamine). 

National Cancer Institute Bioassay of p-Phenylenediamine Dihydrochloride for Possible Carcinogenicity. TR-174, DHEW (NIH) 9-1730, 1979. 

The data for the p-phenylenediamine-silver ion reaction are not accounted for by Bagdasar yan s treatment. On the basis of an adsorption mechanism, the data would suggest that the important phase for the catalyzed reaction is adsorption of the p-phenylenediamine by the silver catalyst. The extent of the adsorption would depend upon the surface conditions of the catalyst, which apparently depend on changes in the protective colloid or in the salt concentration. A catalytic mechanism involving activation of the p-phenylenediamine by the catalyst would be consistent with the observation of Weissberger and Thomas that colloidal silver markedly catalyzes the oxygen oxidation of p-phenylenediamine. 

The electrostatic effect of the poly(4-vinylpyridine)-Cu(II) catalyst was also reported by Dadze et al. 115). Oxidation of ascorbic acid, salicylic acid, and tri-t-butylphenol was accelerated and that of p-phenylenediamine retarded by the poly(4-vinylpyridine) ligand at lower pH. As described in Section IIIA, a polymer-metal complex behaves as a polycation in aqueous solution, and the reaction is sensitive to the charge of low-molecular-weight species. The electrostatic effect due to the polycationic domain of a polymermetal catalyst is also predominant in the oxidation of charged substrates. 

As shown in Table 2 and in Fig. 4, the N—H frequencies of p-phenylenediamine, aniline and mefchylaniline in the adsorbed state are approaching the N—H frequency of benzylamine. This can be easily... 

The chlorinated derivatives of (71) range from yellow to red and possess superior properties, as in the yellow pigment (72) prepared by condensation of p-phenylenediamine with 3,3,4,5,6,7-hexachloroisoindolinone. 

The photooxidation of p-phenylenediamine to the Wurster s Blue radical cation apparently proceeds by photoionization of the excited triplet state of the neutral molecule,219 and it has been suggested that the delayed fluorescence of perylene may be partly due to photoionization of its triplet state and slow subsequent recombination of... 

Benzoquinone l,4-di(bromo imine), BrN C6H4 NBi mw 263 94, N 10.62% crysts, mp expl ca 86, was claimed to have been prepd by Krause(Ref 2) by treating an aq soln of p-phenylenediamine chloride with an excess of bromine water. No an-analysis of the compd was given Refs l)Beil- not found 2)A.Krause,Ber 12,50... 

Benzoquinone-l,4 di(chloro-iniine) [called Benzo-chinon-(1.4)-bis-chlorimid or p-Chinon-bis-chlor-imid in Ger], C1N CBH4 NC1 mw 175.02, N 16.01% ndls(from w) having a si aromatic odor, mp 124 -6°(dec) expl when heated rapidly above the mp readily sol in hot ale, hot AcOH, eth or benz si sol in hot w almost insol in cold w was first prepd by Krause(Ref 2) by treating an ice-cold soln of p-phenylenediamine in dil HC1 with, an excess of chlorinated lime(bleaching powder). 

Ref l).Many methods of prepn are known, of whidi the treatment of p-phenylenediamine with Na nitrite in dil AcOH is described in detail in Ref 6. 

Dissolve 5 mg in 5 ml of 0.1 M hydrochloric acid and add 3 mg of p-phenylenediamine dihydrochloride shake to dissolve and add 0.1 g zinc powder. After mixing, allow to stand for 2 min and add 10 ml of ferric ammonium sulfate solution. A blue or violet-blue color develops [7],... 

Scheme 5.1 The mechanism of oxidative coupling of p-phenylenediamine (primary intermediate) with m-phenylenediamine (coupler).

DuPont102) has used the anodic iodination of aniline as the key step in the formation of p-phenylenediamine. 

Caution. Toxic and stains hands, clothing, and other things on prolonged contact. The free base of p-phenylenediamine and its water soluble salts may cause eczema or other skin irritations. Always wear a good dust mask when working with the powder and gloves when working with the powder or the solutions. 

This fine grain developer has unusually high speed and extremely fine grain due to the combination of p-phenylenediamine and pyrocatechin. 

Polymeric Catalysts such as porphirin-containing poly-(L-phenylalanine)-Fe(III) complex in the dehydrogenation of p-phenylenediamine (132), poly(L-lysine)-protoporphirin Fe(III)-4,4 -dipyridyl complex in the oxidation of cytochrome (133), poly(L-lysine)-Cu(II) complex in the hydrolysis of oligophosphate (134), and poly(L-lysine)-Cu(II) complex in the oxidation of 3,4-dioxyphenylalanine and in the hydrolysis of phenylalanine (135-137) have their own structures. 

These investigations have not been satisfactorily concluded, which is also the case with those of Foelsing,1 who, by the oxidation of p-phenylenediamine and benzene-p-phenylene-diamine, obtained indigo-blue dyes. 

Transfer the solutions into 100-mL separators containing 25 mL of cold water, and rinse the beakers and pH meter electrodes with a few milliliters of cold water, collecting the washings in the respective separator. Add 2 mL of bromine TS, stopper, and mix. Add 2 mL of 2% sodium arsenite solution, stopper, and mix. Add 10 mL of n-butanol to the clear solutions, stopper, and mix. Finally, add 5 mL of p-Phenylenediamine-Pyridine Mixed Reagent, mix, and allow to stand for 15 min. Remove and discard the aqueous phases, and filter the alcohol phases into 1-cm cells. The absorbance of the solution from the Sample Solution, determined at 480 nm with a suitable spectrophotometer, is not greater than that from the Cyanide Standard Solution. 

N-(Tetrahydrofuranmethylation) derivatives of p-phenylenediamine have been prepared and are described (2). 

Hirata Y, Mataga N. (1990) Solvation dynamics of electrons ejected by picosecond dye laser pulse excitation of p-phenylenediamine in several alcoholic solutions. J Phys Chem 94 8503-8505. 

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