Dyes

Dyes

 

Dyes are a series of molecules that provide color to a variety of products, such as clothing and fabric. The plant, Indigofera tintoria is a source of a dye molecule that proves the blue color, indican. Indigo is present in many parts of the world, as noticed by Marco Polo, including Southeast Asia and Africa. The dibromo derivative of indigo, dibromoindigo provides the purple color to clothing and fabric. In order to metabolize the indican to indixol and then into indigo as a functional dye molecule, the leaves of the plant undergo fermentation in a base or in alkaline conditions and are oxidized in the air. Indican, itself, is a precursor to the dye molecule, indigo. However, the dibromo derivative of indigo has been regarded as an imperial color and has been very valuable, along with indigo. The Tyrian purple has been isolated from shellfish of certain mollusks and during 400 A.D., the species of the shellfish were facing extinction. The indican molecule also contains an attached glucose unit, which is replaced with a double bond with an oxygen atom. The oxidation in the air duplicated the molecule and produces a double bond between the two identical molecules. Afterwards, a cloth is dipped into a solution of the dye molecule to produce the clothing of different colors. The German chemist, Johann Friedrich Wilhelm Adolf von Baeyer studied the structure of the indigo molecule and synthesized a synthetic form of the dye molecule, which has affected the cultivation and extraction of natural indigo because tons of synthetic dyes were produced on a large industrial scale to meet the demands for colored clothing and fabric. The compound, Soda Fabrik (BASF) has undergone seven chemical reactions to produce the indigo molecule in the reaction solution. Dye molecules are colored organic compounds that are capable of absorbing certain wavelengths of light from the visible spectrum and reflect another wavelength of light to produce the color of the fabric or cloth, when incorporated. Sunscreen products also absorb ultraviolet light to provide protection against ultraviolet radiation to prevent damage to the skin with the presence of alternating double and single bonds; a conjugated molecule contains these alternating bonds and could contain atoms of oxygen, nitrogen, sulfur, bromine, and chlorine, which will extend the conjugation and increase the wavelength of light being absorbed. The indigo molecule contains twice as more alternating double and single bonds than the indican molecule and contains atoms of oxygen incorporated into its conjugation combination, which provides the energy and the possibility of the molecule to absorb visible light of a certain wavelength, which means that the indigo molecule is colored. Other molecules such as the ones found in cave drawings, contains pigment molecules that are capable of absorbing certain wavelengths of visible light yet are not conjugated with double bonds. Other sources of colors, including calcium ions, chromium, and aluminum were used, along with the alizarin molecule obtained from the Madder plants, which provides a shade of red. Dyes have also been applied to provide recognition and to color army uniforms. The madder plant has been introduced to France in 1766 and became one of the main sources of wealth during the trade of the dyes. Alizarin, or Turkey red, is a derivative of anthraquinone and provided color to a variety of products more efficiently than natural dyes. OH or hydroxyl groups also play a major role in permitting the molecule to absorb certain wavelengths of visible light, along with the number of rings and conjugation combinations. Naphthaquinone is a colorless compound that has two colored derivatives, juglone (brown) and lawsone (reddish-orange à henna). Usually, only the derivatives of certain molecules are colored, while the original molecules are colorless; juglone and lawsone differ from the naphthaquinone molecule because they contain a hydroxyl group attached to one of their rings. Echinochrome, which is a dye molecule that is a derivative of naphthaquinone that contains multiple hydroxyl groups, while a derivative of anthraquinone, carminic acid, also contains multiple hydroxyl groups. This compound has been used to color jackets and is chemically similar to alizarin, is more potent. Approximately 85% of the world’s production of dyes occurs in Peru. Dye molecules are isolated from animals, plants, and from stigmas of plants, which required intense labor, yet whenever synthetic dyes were derived, the industries relating to the isolation of natural dyes slowly became less popular. During the early 1700s, synthetic dyes began to be synthesized and derived, including picric acid, or trinitrophenol. Picric acid provided a bright yellow color, however its explosive potential and difficulty to obtain counteracted its production. In 1868, synthetic alizarin has been available, along with synthetic indigo in 1880, which provided color form clothing, fabric, and a variety of products. In 1856, William Henry Perkin synthesized the antimalarial drug, quinine, during his Easter holidays; once he has dipped a piece of silk into a solution of quinine, the silk has absorbed the dye molecules rapidly and the color did not fade as he exposed the colored silk to light. Perkin received a supportive reply after he sent a sample of the colored silk to a dyeing company in Scotland. His father provided financial support so that Perkin could be able to patent his discovery and began to produce and sell the product. The potential dye, quinine, provided a deep purple color, which Perkin called mauve, has had an increasing demand because purple dyes were very rare and expensive. The chemical dye industry has replaced the techniques of isolating and extracting natural dyes from animal and plant sources and Perkin’s dyes, other than quinine, has been produced, manufactured, and purchased at large scales up until the late 1880s. Quinine could be produced from the oxidation of allytoluidine, which would produce quinine and water. The isolation of natural dyes and the large-scale industrial production and manufacture of synthetic dyes such as Perkin’s mauve, synthetic indigo, alizarin, and carminic acid have affected society and civilization because the dyes have been used to color furnishings, fabric, clothing, and a variety of other materials, which has been responsible for the increasing demand for various dye molecules. The large-scale production of dyes and the dye trade supported the economy and the growth and development of cities, towns, mechanization, industrialization, technological advancements, and provided the scientific knowledge that has been used to derive pharmaceuticals, analgesics, and antibiotics. Therefore, the synthesis of a variety of synthetic dyes and the arduous research of various chemists on the chemical structure of dye molecules lead to the coloring of clothing, fabric, furnishing, and appliances with other dyes and contributed to today’s large availability of clothing and products of any color.