Colorants solubility

In addition to the numeric data (color, solubility, refraction index, spectra, etc.), these factual databases also include a bibliographic section with references or sources and a section with information for the identification of a compound (e.g., name, CAS Registry Number, molecular weight). 

Dyes, often also called coloring matters or colorants, are intensely colored, soluble organic substances used to impart color to fibrous materials (see Textbox 66). Not all colored and soluble organic substances, however, are dyes only those whose molecules have a considerable structural complexity are useful for imparting color to other materials. Moreover, a substance is considered a dye only if the color it imparts is fairly permanent, that is, resistant to fading and disappearance. 

According to the demand for insolubility in water and the commonly used organic solvents, substituents attached to the alkyl, aryl, or heteroaryl groups should not contain sulfo (S03H) groups or long-chain alkyl groups which render the colorant soluble. 

Many publishers make available their databases on floppy disks or CD-ROMs, which are often found inside the back cover of the book. An example is the Properties of Organic Compounds (Tide and Milne 1999), which is a CD-ROM list of 27,500 known organic compounds and their formulas, molecular weights, melting points, boiling points, densities, refractive indexes, colors, solubility scales, vapor pressures, and threshold limit values (TLVs) that workers can be exposed to in a normal 8 h workday and 40 h workweek. This reference gives only a limited number of properties, and does not go into flammability or toxicity. Solubility in water is given only as a... 

Name Formula State Color Solubility AG° (kJ/mole)... 

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