4-chlorophenol-4-phenylenediamine

Chloronaphthalene 40 Chloronitrobenzenes, 40 Chloropentafluoroethane, 40 Chlorophacinone, 40 4-Chloro-o-phenylenediamine, 40 Chlorophenols, 40 Chlorophenols, Mono, 40 Chloropicrin, 40 Chloroplatinic acid, 41 Chloroprene, 41... 

After drying for 10 min in a stream of cold air 1,4-phenylenediamine (h/Jj 5-10), 2-amino-4-chlorophenol (h/ f 15-20), 4-nitroaniline (h/ f 25-30) and l,4-amino-3-nitro-toluene (h/ f 50-55) appeared as blue-violet chromatogram zones on a blue background. These could be recognized without difficulty for several days from the back of the chromatogram. 

The detection limits per chromatogram zone lay between 5 ng (1,4-phenylenediamine, 4-nitroaniline) and 25 ng (2-amino-4-chlorophenol, 4-amino-3-nitrotoluene). 

Fig. 1 Reflectance scan of a chromatogram track with 125 ng each substance per chromatogram zone 1 = 1,4-phenylenediamine, 2 = 2-amino-4-chlorophenol, 3 = 4-nitroaniline, 4 = 4-amino-3-nitrotoluene.

Spectrophotometry (or colorimetry) has been used to measure chlorine dioxide in water using indicators that change colors when oxidized by chlorine dioxide. Spectrophotometric analyzers determine the concentration of chlorine dioxide by measuring the optical absorbance of the indicator in the sample solution. The absorbance is proportional to the concentration of the chlorine dioxide in water. Indicators used for this technique include jV,jV-diethyl-p-phenylenediamine, chlorophenol red, and methylene blue (APHA 1998 Fletcher and Hemming 1985 Quentel et al. 1994 Sweetin et al. 1996). For example, chlorophenol red selectively reacts with chlorine dioxide at pH 7 with a detection limit of 0.12 mg/L. The interferences from chlorine may be reduced by the addition of oxalic acid, sodium cyclamate, or thioacetamide (Sweetin et al. 1996). 

In 1998, Loehlin and co-workers [44] reported the structures of five new crystals of the super-tetrahedral type formed by complementary amines and alcohols. They described the H-bonding networks of three complexes of the diamine type with monoalcohols 4-phenylenediamine (5)-phenol (16) (ratio 1 2, as in 5 16), 4-phenylenediamine (5)-4-phenylphenol (17) (ratio 1 2, as in 5 17), and 4-phenylenediamine (5)-4-chlorophenol (18) (ratio 1 2, as in 5 18) (Scheme 6). Two complexes of 4-phenylenediamine with diols were also reported 4-phenylenediamine (5)-2,6-dihydroxynaphthalene (19) (ratio 1 1, as in 5 19), and 4-phenylenediamine (5)-l,6-hexanediol (20) (ratio 1 1, as in 5 20). The H-bonded networks were... 

Instead, the complex 5 18, between 4-phenylenediamine and 4-chlorophenol, shows a ladder-like pattern of the H-bond network, that is similar to that previously described by Liminga [32,33] for the complex between hydrazine and ethanol (Figure 27). In this case, the ladder-like pattern did not allow the interactions between chlorine atoms on adjacent layers, losing the extra stabilization observed by Desiraju for many others complexes [47]. The authors described some interesting features for the diol moiety arrangement in the complex 4-phenylenediamine-1,6-hexane diol, 5 20 [44]. 

The crystal structures of many o- and p-chlorophenols, but only of a few m-chloro-phenols, are known. Representative examples are l,5-dichloro-2,6-dihydroxynaphthalene (45), a complex between 3,5-dichlorophenol (46) and 2,6-dimethylphenol , and a complex of p-chlorophenol (47) with 1,4-phenylenediamine. The C—OH bond lengths in 45 and 47 are normal (1.364 and 1.361 A, respectively). The same bond in 46 is significantly longer (1.387 A) for unknown reasons. 

Chloronitrobenzene 4-Chloro-3-nitrobenzotrifluoride 4-Chlorophenol 4-Chloro-m-phenylenediamine 4-Chloro-o-phenylenediamine... 

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