| Indigo | |
|---|---|
 |
|
 |
|
| Other names | 2,2’-Bis(2,3-dihydro-3- oxoindolyliden), Indigotin |
| Identifiers | |
| CAS number | [482-89-3] |
| RTECS number | DU2988400 |
| SMILES | O=c3c(=c2[nH]c1ccccc1c2=O)[nH]c4ccccc34 |
| InChI | 1/C16H10N2O2/c19-15-9-5-1-3-7-
11(9)17-13(15)14-16(20)10-6-2-4 -8-12(10)18-14/h1-8,17-18H/b14-13+ |
| Properties | |
| Molecular formula | C16H10N2O2 |
| Molar mass | 262. CAS registry numbers are unique numerical identifiers for Chemical compounds Polymers biological sequences mixtures and Alloys They are also referred to Registry of Toxic Effects of Chemical Substances ( RTECS) is a Database of Toxicity information compiled from the open scientific literature without reference The IUPAC International Chemical Identifier ( InChI, pronounced "INchee" is a textual Identifier for Chemical substances designed to provide a A chemical formula is a way of expressing information about the Atoms that constitute a particular Chemical compound, and how the relationship between those atoms changes Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound) 27 g/mol |
| Appearance | dark blue crystalline powder |
| Density | 1. The density of a material is defined as its Mass per unit Volume: \rho = \frac{m}{V} Different materials usually have different 199 g/cm3 |
| Melting point |
390–392 °C |
| Solubility in water | insoluble at 20 °C |
| Hazards | |
| EU classification | 207-586-9 |
| R-phrases | R36/37/38 |
| S-phrases | S26-S36 |
| Related compounds | |
| Related compounds | Indoxyl Tyrian purple Indican |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
Indigo dye is dye with a distinctive blue color (see indigo). The melting point of a solid is the temperature range at which it changes state from solid to Liquid. Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. Council Directive 67/548/EEC of 27 June 1967 on the approximation of laws regulations and administrative provisions relating to the classification packaging and labelling R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous R-phrases (short for Risk Phrases) are defined in Annex III of European Union Directive 67/548/EEC: Nature of special risks attributed to dangerous S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. S-phrases are defined in Annex IV of European Union Directive 67/548/EEC: Safety advice concerning dangerous substances and preparations. In chemistry indoxyl is a Nitrogenous substance with the Chemical formula: C8H7NO Indican is a colourless Organic compound, soluble in water naturally occurring in Indigofera plants In Chemistry, the standard state of a material is its state at 1 bar (100 Kilopascals exactly A dye can generally be described as a Colored substance that has an affinity to the substrate to which it is being applied Indigo is the Color on the Electromagnetic spectrum between about 420 and 450 nm in Wavelength, placing it between Blue and violet The chemical compound that constitutes the indigo dye is called indigotin. The ancients extracted the natural dye from several species of plant as well as one of the two famous Phoenician sea snails, but nearly all indigo produced today is synthetic. Plants are living Organisms belonging to the kingdom Plantae. Hexaplex trunculus (also known as Murex trunculus or the banded dye-murex) is a medium-sized Species of sea Snail, In Chemistry, chemical synthesis is purposeful execution of Chemical reactions in order to get a product, or several products Historically, indigo played an important role in many countries' economies because natural blue dyes are rare.
Among other uses, it is used in the production of denim cloth for blue jeans. Denim is a rugged Cotton Twill Textile, in which the Weft passes under two ( twi- "double" or more warp fibers A textile is a flexible material comprised of a network of natural or artificial Fibres often referred to as thread or Yarn. Jeans are Trousers made from Denim. Mainly designed for work, they became popular among Teenagers starting in the 1950s. The form of indigo used in food is called "indigotine", and is listed in the USA as FD&C Blue No. The United States of America —commonly referred to as the The United States Federal Food Drug and Cosmetic Act (abbreviated as FFDCA FDCA or FD&C is a set of laws passed by Congress in 1938 giving authority to the 2, and in the European Union as E Number: E132. The European Union ( EU) is a political and economic union of twenty-seven member states, located primarily in E numbers are number codes for Food additives and are usually found on Food labels throughout the European Union.
Contents |
Sources and uses
A variety of plants have provided indigo throughout history, but most natural indigo is obtained from those in the genus Indigofera, which are native to the tropics. Indigofera is a large genus of about 700 species of Flowering plants belonging to the family Fabaceae. The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 In temperate climates indigo can also be obtained from woad (Isatis tinctoria) and dyer's knotweed (Polygonum tinctorum), although the Indigofera species yield more dye. Polygonum tinctorum is Chinese Indigo, a Plant of the Buckwheat family that is found from Eastern Europe to East Asia and whose leaves The primary commercial indigo species in Asia was true indigo (Indigofera tinctoria, also known as Indigofera sumatrana). Indigofera tinctoria bears the common name true indigo. The plant was one of the original sources of Indigo dye. In Central and South America the two species Indigofera suffruticosa (Anil) and Indigofera arrecta (Natal indigo) were the most important. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a
Dye was obtained from the processing of the plant's leaves. These were soaked in water and fermented in order to convert the glycoside indican naturally present in the plant to the blue dye indigotin. Fermentation is the process of deriving energy from the oxidation of organic compounds such as carbohydrates using an endogenous electron acceptor which is Indican is a colourless Organic compound, soluble in water naturally occurring in Indigofera plants Indigo dye is Dye with a distinctive blue color (see Indigo) The chemical compound that constitutes the indigo dye is called indigotin The precipitate from the fermented leaf solution was mixed with a strong base such as lye, pressed into cakes, dried, and powdered. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature The powder was then mixed with various other substances to produce different shades of blue and purple.
Natural indigo was the only source of the dye until July 1897. Within a short time, however, synthetic indigo almost completely superseded natural indigo, and today nearly all indigo produced is synthetic.
In the United States, the primary use for indigo is as a dye for cotton work clothes and blue jeans. The United States of America —commonly referred to as the
For many years indigo was also used to produce deep navy blue colors on wool. Indigo does not bond strongly to wool fibers, and wear and repeated washing slowly removes the dye.
Indigo is also used as a food coloring, and is listed in the USA as FD&C Blue No. A food coloring is any substance that is added to Food or Drink to change its Color. 2. The specification for FD&C Blue No. 2 includes three substances, of which the major one is the sodium salt of Indigotindisulfonate.
Indigotinesulfonate is also used as a dye in renal function testing, as a reagent for the detection of nitrates and chlorates and in the testing of milk. Renal function, in Nephrology, is an indication of the state of the Kidney and its role in Renal physiology. A reagent or reactant is a substance or compound consumed during a Chemical reaction. In Inorganic chemistry, a nitrate is a salt of Nitric acid with an Ion composed of one Nitrogen and three Oxygen atoms The chlorate anion has the formula ClO3− In this case the Chlorine atom is in the +5 Oxidation state.
History
Classical antiquity
Indigo is among the oldest dyes to be used for textile dyeing and printing. Many Asian countries, such as India, China, Japan and South East Asian nations have used indigo as a dye (particularly silk dye) for centuries. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National For a topic outline on this subject see List of basic Japan topics. Silk is a natural Protein Fiber, some forms of which can be woven into Textiles The best-known type of silk is obtained from cocoons The dye was also known to ancient civilizations in Mesopotamia, Egypt, Greece, Rome, Britain, Mesoamerica, Peru, Iran, and Africa. Mesopotamia (from the Greek meaning "land between the rivers" is an area geographically located between the Tigris and Euphrates rivers largely corresponding Ancient Egypt was an Ancient Civilization in eastern North Africa, concentrated along the lower reaches of the Nile River in what is now The term ancient Greece refers to the period of Greek history lasting from the Greek Dark Ages ca Ancient Rome was a Civilization that grew out of a small agricultural community founded on the Italian Peninsula as early as the 10th century BC Prehistoric Britain was a period in the human occupation of Great Britain that was the later part of Prehistory, conventionally ending with the Roman invasion Mesoamerica or Meso-America (Mesoamérica is a Region extending approximately from central Mexico to Honduras and Nicaragua, defined Peru (Perú Piruw Piruw officially the Republic of Peru ( reˈpuβlika del peˈɾu is a country in western South America. For a topic outline on this subject see List of basic Iran topics.
India is believed to be the oldest center of indigo dyeing in the Old World. It was a primary supplier of indigo to Europe as early as the Greco-Roman era. The association of India with indigo is reflected in the Greek word for the dye, which was indikon. The Romans used the term indicum, which passed into Italian dialect and eventually into English as the word indigo.
In Mesopotamia, a Neo-Babylonian cuneiform tablet of the 7th century BC gives a recipe for the dyeing of wool, where lapis-colored wool (uqnatu) is produced by repeated immersion and airing of the cloth. Indigo was most probably imported from India.
The Romans used indigo as a pigment for painting and for medicinal and cosmetic purposes. It was a luxury item imported to the Mediterranean from India by Arab merchants.
Indigo remained a rare commodity in Europe throughout the Middle Ages. Woad, a chemically identical dye derived from the plant Isatis tinctoria (Brassicaceae), was used instead. Isatis ( ''Í-sa-tis'') is a genus of about 30 species of Flowering plants in the family Brassicaceae, native to the Mediterranean Brassicaceae or Cruciferae, also known as the crucifers, the mustard family or cabbage family is a family (the third lowest primary
In the late fifteenth century, the Portuguese explorer Vasco da Gama discovered a sea route to India. Portugal, officially the Portuguese Republic (República Portuguesa is a country on the Iberian Peninsula. Dom Vasco da Gama, 1st Count of Vidigueira ('vaʃku dɐ 'gɐmɐ ( Sines or Vidigueira, Alentejo, Portugal, ca This led to the establishment of direct trade with India, the Spice Islands, China, and Japan. This article covers the historical role of the Maluku Islands as a source of spices since early history when the islands where known as the Spice Islands Importers could now avoid the heavy duties imposed by Persian, Levantine, and Greek middlemen and the lengthy and dangerous land routes which had previously been used. For a topic outline on this subject see List of basic Iran topics. See also Names of the Levant The Levant (lə'vænt is a geographical term that denotes a large area in Western Asia, roughly bounded on the north by the Consequently, the importation and use of indigo in Europe rose significantly. Much European indigo from Asia arrived through ports in Portugal, the Netherlands, and England. The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands Spain imported the dye from its colonies in South America. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. Many indigo plantations were established by European powers in tropical climates; it was a major crop in Jamaica and South Carolina, with much or all of the labor performed by enslaved Africans and African-Americans. Jamaica (ˈdʒəˈmeɪkə} is an Island nation of the Greater Antilles, in length and as much as in width situated in the Caribbean Sea. South Carolina ( is a state in the southern region ( Deep South) of the United States of America. Indigo plantations also thrived in the Virgin Islands. See also Culture of the Virgin Islands Music of the Virgin Islands Virgin Islands Creole However, France and Germany outlawed imported indigo in the 1500s to protect the local woad dye industry. This article is about the country For a topic outline on this subject see List of basic France topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.
Indigo was the foundation of centuries-old textile traditions throughout West Africa. West Africa or Western Africa is the Westernmost Region of the African Continent. From the Tuareg nomads of the Sahara to Cameroon, clothes dyed with indigo signified wealth. The Tuareg (also Twareg or Touareg, Amazigh: Imuhagh / Itargiyen, besides regional ethnyms are a Nomadic The Sahara (الصحراء الكبرى aṣ-ṣaḥrā´ al-kubra, "The Great Desert" is the world's largest hot Desert and the world's second largest The Republic of Cameroon is a unitary republic of central and western Africa. Women dyed the cloth in most areas, with the Yoruba of Nigeria and the Manding of Mali particularly well known for their expertise. The Yoruba (Yo•row•ba ( Yorùbá in Yoruba Orthography) are one of the largest ethno-linguistic or Ethnic groups in West Africa Nigeria, officially named the Federal Republic of Nigeria, is a federal Constitutional republic comprising thirty-six states and one Federal Mali, officially the Republic of Mali (République du Mali is a Landlocked nation in Western Africa. Among the Hausa male dyers working at communal dye pits were the basis of the wealth of the ancient city of Kano, and can still be seen plying their trade today at the same pits. The Hausa are a Sahelian people chiefly located in the West African regions of northern Nigeria and southeastern Niger. Kano is the administrative center of the Kano State and the third largest City in Nigeria, in terms
In Japan, indigo became especially important in the Edo period when it was forbidden to use silk, so the Japanese began to import and plant cotton. The, also referred to as the Tokugawa period (徳川時代 Tokugawa-jidai) is a division of Japanese history running from 1603 to 1868 It was difficult to dye the cotton fiber except with indigo. Even today indigo is very much appreciated as a color for the summer Kimono Yukata, as this traditional clothing recalls Nature and the blue sea. The is the National costume of Japan. Originally the word "kimono" literally meant thing to wear ( ki wearing and mono thing but now has come
Late 19th century
In 1865 the German chemist Adolf von Baeyer began working with indigo. Year 1865 ( MDCCCLXV) was a Common year starting on Sunday (link will display the full calendar of the Gregorian calendar (or a Common year Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Johann Friedrich Wilhelm Adolf von Baeyer (ˈbaɪɐ October 31, 1835 - August 20, 1917) was a German chemist who His work culminated in the first synthesis of indigo in 1878 from Istatine, a second synthesis in 1880 from o-nitrobenzaldehyde and acetone upon addition of dilute sodium hydroxide, barium hydroxide, or ammonia and the announcement of its chemical structure three years later. Year 1878 ( MDCCCLXXVIII) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar (or a Common Year 1880 ( MDCCCLXXX) was a Leap year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Leap year Acetone (also known as propanone, dimethyl ketone, 2-propanone, propan-2-one and β-ketopropane) is a colorless mobile flammable
The production of o-nitrobenzaldehyde was too complicated for a commercial product so the search for alternative starting materials was crucial for BASF and Hoechst. The synthesis of N-(2-Carboxyphenyl)glycine starting from the easy to obtain anthracene gave the development of a synthesis a boost. Anthracene is a solid Polycyclic aromatic hydrocarbon consisting of three fused Benzene rings derived from Coal-tar.
BASF developed a commercially feasible manufacturing process that was in use by 1897, and by 1913 natural indigo had been almost entirely replaced by synthetic indigo. BASF SE () is a German chemical company and the largest chemical company in the world Year 1897 ( MDCCCXCVII) was a Common year starting on Friday (link will display the full calendar of the Gregorian Calendar (or a Common Year 1913 ( MCMXIII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common In 2002, 17,000 tons of synthetic indigo were produced worldwide. See also 2002 (disambiguation Year 2002 ( MMII) was a Common year starting on Tuesday of the Gregorian calendar.
In the nineteenth century, the British obtained much indigo from India. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country With the coming of the synthetic substitute, the demand for natural indigo dropped and indigo farming became unprofitable.
In literature, the play Nildarpan by Dinabandhu Mitra is based on the indigo slavery and forceful cultivation of indigo in India. Dinabandhu Mitra (দীনবন্ধু মিত্র (1830-1873 the Bengali dramatist was born in 1830 at Chouberia in Nadia, and was the son of Kalachand Dinabandhu Mitra (দীনবন্ধু মিত্র (1830-1873 the Bengali dramatist was born in 1830 at Chouberia in Nadia, and was the son of Kalachand It played an essential part in the Bengali indigo revolt of 1858 called Nilbidraha. Etymology and ethnology The exact origin of the word Bangla or Bengal is unknown though it is believed to be derived from the Dravidian-speaking tribe Bang The Indigo revolt ( Bangla:নীল বিদ্রহ Neel bidrōhō) was a peasant movement and subsequent uprising of indigo farmers' against the indigo planters
Developments in dyeing technology
Indigo is a challenging dye to use because it is not soluble in water; to be dissolved, it must undergo a chemical change (reduction). Solubility is the characteristic Physical property referring to the ability of a given substance the Solute, to dissolve in a Solvent. Water is a common Chemical substance that is essential for the survival of all known forms of Life. When a submerged fabric is removed from the dyebath, the indigo quickly combines with oxygen in the air and reverts to its insoluble form. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the When it first became widely available in Europe in the sixteenth century, European dyers and printers struggled with indigo because of this distinctive property. It also required several chemical manipulations, some involving toxic materials, and had many opportunities to injure workers. In fact, during the 19th century, English poet William Wordsworth referred to the plight of indigo dye workers of his hometown of Cockermouth in his autobiographical poem "The Prelude". Speaking of their dire working conditions and the empathy that he feels for them, he writes, "Doubtless, I should have then made common cause/ With some who perished; haply perished too,/ A poor mistaken and bewildered offering - / Unknown to those bare souls of miller blue. "
A preindustrial process for dyeing with indigo, used in Europe, was to dissolve the indigo in stale urine. Urine reduces the water-insoluble indigo to a soluble substance known as indigo white or leucoindigo, which is yellow, but because small amounts are easily oxidizied to indigo, the solution is often yellow-green. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Fabric dyed in the solution turns blue after the indigo white oxidizes and returns to indigo. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state Synthetic urea to replace urine became available in the 1800s. Urea is an Organic compound with the Chemical formula ( N[[hydrogen H]]22 C[[oxygen O]]
Another preindustrial method, used in Japan, was to dissolve the indigo in a heated vat in which a culture of thermophilic, anaerobic bacteria was maintained. For a topic outline on this subject see List of basic Japan topics. A thermophile is an organism &mdash a type of Extremophile &mdash which thrives at relatively high temperatures between 45 and 80 °C (113 and 176 °F Anaerobic digestion is a series of processes in which Microorganisms break down Biodegradable material in the absence of Oxygen. Some species of such bacteria generate hydrogen as a metabolic product, which can convert insoluble indigo into soluble indigo white. Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Cloth dyed in such a vat was decorated with the techniques of shibori (tie-dye), kasuri, katazome, and tsutsugaki. Shibori is a Japanese term for several methods of Dyeing cloth with a pattern by binding stitching folding twisting or compressing it Kasuri ( 絣)is a Japanese word for fabric that has been woven with fibers dyed specifically to create patterns and images in the fabric Katazome (型染め is a Japanese method of Dyeing fabrics using a resist paste applied through a Stencil. Tsutsugaki (ja 筒描 is a Japanese term for the practice of drawing designs in rice paste on cloth dyeing the cloth and then washing the paste off Examples of clothing and banners dyed with these techniques can be seen in the works of Hokusai and other artists. was a Japanese Artist, Ukiyo-e painter and Printmaker of the Edo period.
Two different methods for the direct application of indigo were developed in England in the eighteenth century and remained in use well into the nineteenth century. The first method, known as pencil blue because it was most often applied by pencil or brush, could be used to achieve dark hues. Arsenic trisulfide and a thickener were added to the indigo vat. Arsenic trisulfide is the Chemical compound with the formula As2[[Sulfur S3]] The arsenic compound delayed the oxidation of the indigo long enough to paint the dye onto fabrics.
The second method was known as china blue due to its resemblance to Chinese blue-and-white porcelain. Instead of using an indigo solution directly, the process involved printing the insoluble form of indigo onto the fabric. The indigo was then reduced in a sequence of baths of iron(II) sulfate, with air-oxidation between each immersion. Iron(II sulfate or ferrous sulfate is the Chemical compound with the formula ( Fe[[Sulfur S]] O 4 The china blue process could make sharp designs, but it could not produce the dark hues possible with the pencil blue method.
Around 1880 the glucose process was developed. Year 1880 ( MDCCCLXXX) was a Leap year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Leap year It finally enabled the direct printing of indigo onto fabric and could produce inexpensive dark indigo prints unattainable with the china blue method.
Since 2004 freeze dried indigo, or instant indigo, has become available. Freeze drying (also known as lyophilization or cryodesiccation) is a Dehydration process typically used to preserve a perishable material In this method the indigo has already been reduced, and then freeze dried into a crystal. The crystals are added to warm water to create the dye pot. As in a standard indigo dye pot, care has to be taken to avoid mixing in oxygen. Freeze dried indigo is simple to use, and the crystals can be stored indefinitely as long as they are not exposed to moisture. [1]
Chemical properties
Indigo is a dark blue crystalline powder that sublimes at 390°–392°C. It is insoluble in water, alcohol, or ether but soluble in chloroform, nitrobenzene, or concentrated sulfuric acid. Diethyl ether, also known as ether and ethoxyethane, is a clear colorless and highly Flammable liquid with a low Boiling point and a Chloroform, also known as trichloromethane and methyl trichloride, is a Chemical compound with formula C[[Hydrogen H]] Cl Nitrobenzene, also known as nitrobenzol or oil of mirbane, is an Organic compound with the Chemical formula C 6 Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid. The chemical structure of indigo corresponds to the formula C16H10N2O2. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the
The naturally occurring substance is indican, which is colorless and soluble in water. Indican is a colourless Organic compound, soluble in water naturally occurring in Indigofera plants Indican can easily be hydrolyzed to β-D-glucose and indoxyl. Indican is a colourless Organic compound, soluble in water naturally occurring in Indigofera plants Hydrolysis is a Chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions which may go on to participate in further reactions Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. In chemistry indoxyl is a Nitrogenous substance with the Chemical formula: C8H7NO Mild oxidation, such as by exposure to air, converts indoxyl to indigo. Redox (shorthand for reduction-oxidation reaction describes all Chemical reactions in which atoms have their Oxidation number ( Oxidation state
The manufacturing process developed in the late 1800s is still in use throughout the world. In this process, indoxyl is synthesized by the fusion of sodium phenylglycinate in a mixture of sodium hydroxide and sodamide. In chemistry indoxyl is a Nitrogenous substance with the Chemical formula: C8H7NO Sodium (ˈsoʊdiəm is an element which has the symbol Na( Latin natrium, from Arabic natrun) atomic number 11 atomic mass 22 Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature
Several simpler compounds can be produced by decomposing indigo; these compounds include aniline and picric acid. Aniline, phenylamine or aminobenzene is an Organic compound with the formula C6H7N "TNP" redirects here For the airport with the IATA airport code TNP see Twentynine Palms Airport. The only chemical reaction of practical importance is its reduction by urea to indigo white. Urea is an Organic compound with the Chemical formula ( N[[hydrogen H]]22 C[[oxygen O]] The indigo white is reoxidized to indigo after it has been applied to the fabric.
Indigo treated with sulfuric acid produces a blue-green color. It became available in the mid-1700s. Sulfonated indigo is also referred to as Saxon blue or indigo carmine. Indigo Carmine, or 55'-indigodisulfonic acid sodium salt is a PH indicator with the Chemical formula C 16 H 8 N
Tyrian purple was a valuable purple dye in antiquity. It was made from excretions of a common Mediterranean Sea snail. In 1909 its structure was shown to be 6,6′-dibromoindigo. Year 1909 ( MCMIX) was a Common year starting on Friday (link will display full calendar of the Gregorian calendar (or a Common year starting It has never been produced synthetically on a commercial basis.
The SMILES structure of indigo is O=c3c(=c2[nH]c1ccccc1c2=O)[nH]c4ccccc34 and its CAS number is [].
Chemical synthesis
The Baeyer-Drewson indigo synthesis is a method dating back to 1882. The Baeyer-Drewson indigo synthesis (1882 is an Organic reaction in which indigo is prepared from O-nitrobenzaldehyde and Acetone Indigo may be synthetically manufactured in a number of different ways. The original method, first used to synthesise indigo by Heumann in 1897, involves heating N-(2-Carboxyphenyl)glycine acid to 200°C in an inert atmosphere with sodium hydroxide. Sodium hydroxide ( Na[[hydroxide OH]]) also known as Lye, caustic soda and (incorrectly according to IUPAC nomenclature This produces indoxyl-2-carboxylic acid, a material that readily decarboxylates and oxidises in air to form indigo.
The modern synthesis of indigo is slightly different from that route originally used and its discovery is credited to Pfleger in 1901. In this process, N-phenylglycine is treated with an alkaline melt of sodium and potassium hydroxides containing sodamide. Sodium amide, commonly called sodamide is the Chemical compound with the formula NaNH2 This produces indoxyl, which is subsequently oxidised in air to form indigo. In chemistry indoxyl is a Nitrogenous substance with the Chemical formula: C8H7NO
External links
- Plant Cultures: botany, history and uses of indigo
- Pubchem page for indigotine
- FD&C regulation on indigotine
References
- ^ Judith McKenzie McCuin. Directions for Instant Indigo. Retrieved on 2008-05-06. 2008 ( MMVIII) is the current year in accordance with the Gregorian calendar, a Leap year that started on Tuesday of the Common Events 1527 - Spanish and German troops sack Rome; some consider this the end of the Renaissance.
Further reading
- Balfour-Paul, Jenny (1998). Indigo. London: British Museum Press, 264 pages.
- Ferreira, E. S. B. ; Hulme A. N. , McNab H. , Quye A. (2004). "The natural constituents of historical textile dyes". Chemical Society reviews 33 (6): 329. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- Sequin-Frey, Margareta (1981). "The chemistry of plant and animal dyes". Journal of Chemical Education 58 (4).
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic