Quinacridones

Quinacridone is the trivial name given to the five-ring heterocyclic system exemplified by the linear irani-quinacridone (2.69). The yellow-red to reddish-violet shade pigments based on this ring system show outstanding durability and are used in plastics, in industrial and automotive finishes and in exterior finishes. Like copper phthalocyanines the unsubstituted linear quinacridone exhibits polymorphism and two crystal forms, the reddish violet P-form and the red y-form, are commercially 

Cl name atoms Crystal modification Stability Shade Halogen atoms 

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ANTTBIOTTCS - BETA-LACTAMS - BETA-LACTAMASE INHIBITORS] (Vol 3) Quinacridone [1047-16-1]... 

Pigment Red 122 [980-26-7] 73915 Quinacridone condensation of diakyl succiuoylsucciaate with -toluidine, foUowed by oxidation and hydrolysis, and acid-cataly2ed cycli2ation of 2,5-di(p-toluidino)-terephthahc acid... 

Pigment Red 202 [68859-50-7] 73907 Quinacridone condensation of dialkyl succiuoyl-succiaate with -chloroanUine, cycli2ation of resulting diester to 2,9-dichloro-6,13-dihydroquiQacri-done, foUowed by oxidation... 

Fig. 3. Synthesis of quinacridones where (1) is dialkyl 2,5-diarylamino-3,6-dihydroterephthalate. See Table 6 for representative groups.

Due to the excellent pigmentary properties, quinacridones are used in many industries but particularly in automotive finishes, emulsion paints, plastics, and fibers. 

An important use of dialkyl succinates is in the preparation of dialkyl succinyl succinates (35,53—56), which are intermediates in the manufacture of quinacridone pigments. The reaction is carried out in the presence of alkaU metal alkoxides (eq. 2). 

Quinacridone Pigments. The quinactidones have the following formula ... 

Practical methods for synthesis and elucidation of the optimum physical forms were developed at Du Pont (13). The violets fill the void in the color gamut when the inorganics are inadequate. The quinacridones may be used in most resins except polymers such as nylon-6,6, polystyrene, and ABS. They are stable up to 275°C and show excellent weatherabiUty. One use is to shade phthalocyanines to match Indanthrone Blue. In carpeting, the quinacridones are recommended for polypropylene, acrylonitrile, polyester, and nylon-6 filaments. Predispersions in plastici2ers ate used in thermoset polyesters, urethanes, and epoxy resins (14). 

Quaternary ammonium compounds biocidal activity mechanism, 1, 401 toxicity, 1, 124 Quaternization heterocyclic compounds reviews, 1, 73 ( )-Quebrach amine synthesis, 1, 490 Queen substance synthesis, 1, 439 4, 777 Quercetin occurrence, 3, 878 pentamethyl ether photolysis, 3, 696 photooxidation, 3, 695 Quercetrin hydrolysis, 3, 878 Quinacetol sulfate as fungicide, 2, 514 Quinacridone, 2,9-dimethyl-, 1, 336 Quinacridone pigments, 1, 335-336 Quinacrine... 

Fluorescent small molecules are used as dopants in either electron- or hole-transporting binders. These emitters are selected for their high photoluminescent quantum efficiency and for the color of their emission. Typical examples include perylene and its derivatives 44], quinacridones [45, penlaphenylcyclopenlcne [46], dicyanomethylene pyrans [47, 48], and rubrene [3(3, 49]. The emissive dopant is chosen to have a lower excited state energy than the host, such that if an exciton forms on a host molecule it will spontaneously transfer to the dopant. Relatively small concentrations of dopant are used, typically in the order of 1%, in order to avoid concentration quenching of their luminescence. 

Figure 4.6 Intermolecular association by hydrogen bonding in the crystal lattice of linear trans quinacridone, 65a...

Quinacridone derivatives with four alky chains. 

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