Nile Blue

Nile blue - (syn.: nil blau sulfate, Nile blue sulfate). Nile sulfate (Nile blue sulfate).

Sodium sulfate and chalcogenides of Group VIII elements are generally classified as blue sulfin dyes. The color of these dyes is due to the presence of metal (including its chalcosame) in the chromophore ring, consisting of (4, x, 4,5), (6,4, 6), (7,4,7) or (6-7) cycles. This class of dyes most often includes colored solutions of sodium hydrosulfides. Because of the yellow salt (sodium dioxide), these solutions have a yellow color. Coloring with this dye from bright blue to green-blue is also common, with the addition of salts of ionic silver compounds. More concentrated solutions contain violet-colored substances

Nile blue or Nile blue is a bright blue synthetic dye obtained from organic compounds of the benzene ring. It is a type of blue sulfate formed by adding sulfuric acid to an alkaline solution of copper chloride CuCl2 and aniline: CuCl2 + 3 C6H13NH3 + H2SO4 → (Cu(NH3)4)(H2SO4)Cl. When producing NiB, CuCl2 acts as a catalyst. Nile blue is used in the plastics industry, textiles, photography, and as a component of organic paints.

An important element for obtaining this paint is copper II sulfate. By adding copper sulfate to the solution, copper II reacts with aniline, forming a complex that releases aniline into the solution: CuSO4 + 4C6H5NH2 → Cu2(C6H7NH3) + 2H2O2. Other reaction reagents necessary for the formation of the complex are dimethylaniline, α-aminobenzene, ammonia, sulfuric acid and several other compounds. As a result of the reaction, a white, blue precipitate is formed, which is characterized by high chemical resistance. This is due to the presence of positively charged copper (II) ions, which can bind to the negatively charged regions of the molecules of complex compounds.