It is produced synthetically by converting p-aminobenzamide into the corresponding diazonium compound followed by coupling with 3-hydroxy-2-naphththoic acid (2-ethoxy)anilide ("Naphtol AS-PH" dye precursor).
In the solid state the hydrazo tautomer forms and several crystal structures exist. In the initial α polymorph the molecules are arranged in a herringbone pattern with extensive hydrogen bonding. The φ polymorph is more dense and more stable and produced industrially by thermal treatment in water at 130°C under pressure. In this phase the molecules are planar and arranged in layers. Extensive hydrogen bonding exists within the layer but between layers the only interactions are Van der Waals forces. Dense crystal structures are preferred for pigments used in coatings because in the event of photochemicaldecomposition the fragments are locked in place and are able to recombine. Research shows that by replacing the ethoxy group in this compound by a methoxy group the crystal structure is less stable and in the final application and the color fades more easily. By careful selection of substituents it is possible to optimize crystal structure and improve optical properties [1].
Referencesedit
^Crystal Structures of Pigment Red 170 and Derivatives, as Determined by X-ray Powder Diffraction Martin U. Schmidt, Detlef W. M. Hofmann, Christian Buchsbaum, Hans Joachim Metz, Angewandte Chemie International Edition Volume 45, Issue 8, Pages 1313 - 1317 2006 Abstract
April 11, 2024
naphthol, confused, with, naphthol, pigment, pr170, organic, pigment, extensively, used, automotive, coatings, painting, namesiupac, name, carbamoylphenyl, hydrazono, ethoxyphenyl, dihydronaphthalene, carboxamideother, names, 12475, pigment, 170identifierscas,. Not to be confused with 2 naphthol red Naphthol Red Pigment red 170 or PR170 is an organic pigment extensively used in automotive coatings and painting Naphthol Red NamesIUPAC name 4 2 4 carbamoylphenyl hydrazono N 2 ethoxyphenyl 3 oxo 3 4 dihydronaphthalene 2 carboxamideOther names C I 12475 C I Pigment Red 170IdentifiersCAS Number 2786 76 7 Y3D model JSmol Interactive imageChemSpider 4514376 YECHA InfoCard 100 018 645PubChem CID 5359812UNII 54O6PK8790 YCompTox Dashboard EPA DTXSID7029243InChI InChI 1S C26H22N4O4 c1 2 34 22 10 6 5 9 21 22 28 26 33 20 15 17 7 3 4 8 19 17 23 24 20 31 30 29 18 13 11 16 12 14 18 25 27 32 h3 15 29H 2H2 1H3 H2 27 32 H 28 33 b30 23 YKey PYUYQYBDJFMFTH WMMMYUQOSA N YSMILES O C1C C NC2 CC CC C2OCC O CC3 CC CC C3 C1 N NC4 CC C C N O C C4PropertiesChemical formula C 26H 22N 4O 4Molar mass 454 486 g mol 1Density 1 317 g mlExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Y verify what is Y N Infobox references It is produced synthetically by converting p aminobenzamide into the corresponding diazonium compound followed by coupling with 3 hydroxy 2 naphththoic acid 2 ethoxy anilide Naphtol AS PH dye precursor In the solid state the hydrazo tautomer forms and several crystal structures exist In the initial a polymorph the molecules are arranged in a herringbone pattern with extensive hydrogen bonding The f polymorph is more dense and more stable and produced industrially by thermal treatment in water at 130 C under pressure In this phase the molecules are planar and arranged in layers Extensive hydrogen bonding exists within the layer but between layers the only interactions are Van der Waals forces Dense crystal structures are preferred for pigments used in coatings because in the event of photochemical decomposition the fragments are locked in place and are able to recombine Research shows that by replacing the ethoxy group in this compound by a methoxy group the crystal structure is less stable and in the final application and the color fades more easily By careful selection of substituents it is possible to optimize crystal structure and improve optical properties 1 References edit Crystal Structures of Pigment Red 170 and Derivatives as Determined by X ray Powder Diffraction Martin U Schmidt Detlef W M Hofmann Christian Buchsbaum Hans Joachim Metz Angewandte Chemie International Edition Volume 45 Issue 8 Pages 1313 1317 2006 Abstract Retrieved from https en wikipedia org w index php title Naphthol Red amp oldid 1147949514, wikipedia, wiki, book, books, library,
