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Crystal Pigment Violet

The most common of the xanthophyll pigments, it is present in all green leaves, in blossoms and in various animal sources. It crystallizes in violet prisms with one molecule of methanol m.p. I93 C, soluble in organic solvents giving yellow solutions, li is related to a-carolene in the same way as zeaxanlhin is to /1-carolene. [Pg.243]

Heading the list are two crystal modifications of Pigment Violet 19 (the parent compound of the quinacridone series). Both the red-violet (3- and the red -y-mod-ification are encountered in the market, while the pure a-form is not lightfast and durable enough to have any commercial value. However, traces of the a-modifi-cation are found in a variety of types. [Pg.462]

The three-dimensional crystal structure of Pigment Violet 23 (117) elucidates molecular staples whereby the stables of the single molecular planes are arranged in an almost perpendicular orientation to each other. Interactions of the -ir-orbitals as well as van der Waals forces are responsible for the cohesion of the structure. The degree of overlapping is especially high in the dioxazine part of the molecule [3],... [Pg.533]

In contrast to Methyl Violet, Crystal Violet (127) is a uniform compound. This is the dye which constitutes Pigment Violet 39. [Pg.552]

Pigment Violet 19 is polymorphic, and can be produced in a blue shade (beta crystal) that is a bright red shade violet and in a yellow shade (gamma form) that is a deep red. By adjusting the particle size QA suppliers can produce a variety of red and violet shades. [Pg.10]

More recently, it has been demonstrated unequivocally, by single crystal X-ray diffraction analysis, that the molecular structure of Pigment Violet 23 does possess the angular configuration 3, the result of an A-E fusion. In conjunction with that same research it has been demonstrated also that the linear structure affords a blue shade product that apparently has no commercial importance as a pigment. [Pg.186]

Pigment Violet 23 crystallizes in the monocUnic space group P2,/c with lattice parameters of a = 15.717 A, b= 4.666 A, c= 18.12 A, a = y = 90°, p = 104.76°. The unit cell contains two molecules. The molecules are stacked in columns parallel to the b-axis (Figures 20.4b and c). Inside the columns the molecules are connected by van der Waals interactions. (A special "k-k interaction does not seem reasonable for any commercial organic pigment in all cases there are only van der Waals interactions, enhanced by some Coulomb interactions between the partial charges on the atoms). [Pg.344]

Imidazohne-Annellated Triphenedioxazine Pigments J51 20.3.3.3 Crystal Engineering Pigment Violet 57... [Pg.351]

Figure 20.12 Molecular packing in the crystal structures of (a) Pigment Blue 80 (b) Pigment Violet 57 (solid solution of4b+4c+4d, p-phase). View along the b-axis. Figure 20.12 Molecular packing in the crystal structures of (a) Pigment Blue 80 (b) Pigment Violet 57 (solid solution of4b+4c+4d, p-phase). View along the b-axis.
Crystal structure In certain cases, chemically identical pigments existing in different crystal forms (also known as polymorphisms) may exhibit a different hue. Pigments that clearly show the effect of polymorphism on hue are quinacridone pigment (Pigment Violet 19), phthalocyanine pigment (Pigment Blue 15) and lead chromates. [Pg.145]

Although treated as separate classes in the Colour Index, these structural types are closely related and the few diphenylmethane dyes such as auramine (1.28 Cl Basic Yellow 2) are now of little practical interest. Commercial usage of the triarylmethane dyes and pigments has also declined considerably in favour of the major chemical classes. They were formerly noteworthy contributors to the acid, basic, mordant and solvent ranges, primarily in the violet, blue and green sectors. Numerous structural examples are recorded in the Colour Index. The terminal groupings can be amine/quinonimine, as in auramine and crystal violet (1.29 Cl Basic Violet 3), hydroxy/quinone, or both. The aryl nuclei are not always benzenoid (section 6.5). [Pg.12]

The product may be obtained from tetraethyldiaminobenzophenone and N-ethylnaphthylamine with phosphorus oxychloride or with phosphorus trichloride, the route parallels the synthesis of Crystal Violet. The resulting colorant is the basic dye for Pigment Blue 1. [Pg.553]

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... [Pg.120]

Sahoo, C., A.K. Gupta and A. Pal (2005). Photocatalytic degradation of crystal violet (Ci basic violet 3) on silver ion doped Ti02. Dyes and Pigments, 66(3), 189-196. [Pg.437]


See other pages where Crystal Pigment Violet is mentioned: [Pg.165]    [Pg.108]    [Pg.104]    [Pg.1581]    [Pg.1582]    [Pg.341]    [Pg.205]    [Pg.304]    [Pg.80]    [Pg.81]    [Pg.186]    [Pg.149]    [Pg.8]    [Pg.11]    [Pg.14]    [Pg.448]    [Pg.464]    [Pg.381]    [Pg.227]    [Pg.95]    [Pg.859]    [Pg.119]    [Pg.551]    [Pg.400]    [Pg.112]    [Pg.262]    [Pg.348]    [Pg.379]    [Pg.112]    [Pg.1276]    [Pg.76]    [Pg.166]    [Pg.174]    [Pg.112]    [Pg.267]   
See also in sourсe #XX -- [ Pg.57 , Pg.351 ]




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