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Octahydroxyanthraquinone
Octahydroxyanthraquinone is an organic compound with formula , formally derived from anthraquinone by replacement of 8 hydrogen atoms by hydroxyl groups. The compound was obtained in 1911 by Georg von Georgievics Wahl, Andre; Atack, F. W (1919) ''The Manufacture Of Organic Dyestuffs''. G. Bell And Sons, LimitedOnline versionaccessed on 2010-01-22. and can be obtained through oxidation of rufigallol ( 1,2,3,5,6,7-hexahydroxyanthraquinone) with boric acid and mercuric oxide in sulfuric acid at . Esters of octahydroxyanthraquinone, where all eight hydroxyls are replaced by straight-chain 1-alkanecarboxylate groups -()''n''-COO-, with ''n'' between 6 and 14, are liquid crystals and have been studied for possible LCD applications. Octahydroxyanthraquinone is active against the malaria parasite, but rufigallol Rufigallol or 1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone is an organic compound with formula , which can be viewed as a derivative of anthraquinone through the replac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rufigallol
Rufigallol or 1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone is an organic compound with formula , which can be viewed as a derivative of anthraquinone through the replacement of six hydrogen atoms (H) by hydroxyl groups (OH). The compound is soluble in dioxane, from which it crystallizes as red needles that sublime without melting at 365 °C. It can be obtained by treating gallic acid with concentrated sulfuric acid and then with sodium hydroxide. Rufigallol is particularly toxic to the malarial parasite ''Plasmodium falciparum'' and has a synergistic effect in combination with the antimalarial drug exifone, which has structural similarities to rufigallol.R. W. WINTER, KENNETH A. CORNELL, LINDA L. JOHNSON, MARINA IGNATUSHCHENKO,DAVID J. HINRICHS and MICHAEL K. RISCOE (1996), ''Potentiation of the Antimalarial Agent Rufigallol''. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Vol. 40, No. 6, pages 1408–1411Online versionaccessed on 2010-02-01. Rufigallol forms a crimson-colored comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,2,3,5,6,7-hexahydroxyanthraquinone
Rufigallol or 1,2,3,5,6,7-hexahydroxy-9,10-anthraquinone is an organic compound with formula , which can be viewed as a derivative of anthraquinone through the replacement of six hydrogen atoms (H) by hydroxyl groups (OH). The compound is soluble in dioxane, from which it crystallizes as red needles that sublime without melting at 365 °C. It can be obtained by treating gallic acid with concentrated sulfuric acid and then with sodium hydroxide. Rufigallol is particularly toxic to the malarial parasite ''Plasmodium falciparum'' and has a synergistic effect in combination with the antimalarial drug exifone, which has structural similarities to rufigallol.R. W. WINTER, KENNETH A. CORNELL, LINDA L. JOHNSON, MARINA IGNATUSHCHENKO,DAVID J. HINRICHS and MICHAEL K. RISCOE (1996), ''Potentiation of the Antimalarial Agent Rufigallol''. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Vol. 40, No. 6, pages 1408–1411Online versionaccessed on 2010-02-01. Rufigallol forms a crimson-colored comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Living t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthraquinone
Anthraquinone, also called anthracenedione or dioxoanthracene, is an aromatic organic compound with formula . Isomers include various quinone derivatives. The term anthraquinone however refers to the isomer, 9,10-anthraquinone (IUPAC: 9,10-dioxoanthracene) wherein the keto groups are located on the central ring. It is a building block of many dyes and is used in bleaching pulp for papermaking. It is a yellow, highly crystalline solid, poorly soluble in water but soluble in hot organic solvents. It is almost completely insoluble in ethanol near room temperature but 2.25 g will dissolve in 100 g of boiling ethanol. It is found in nature as the rare mineral hoelite. Synthesis There are several current industrial methods to produce 9,10-anthraquinone: # The oxidation of anthracene. Chromium(VI) is the typical oxidant. # The Friedel-Crafts reaction of benzene and phthalic anhydride in presence of AlCl3. o-Benzoylbenzoic acid is an intermediate. This reaction is useful for produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic, and highly combustible. Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all normal matter.However, most of the universe's mass is not in the form of baryons or chemical elements. See dark matter and dark energy. Stars such as the Sun are mainly composed of hydrogen in the plasma state. Most of the hydrogen on Earth exists in molecular forms such as water and organic compounds. For the most common isotope of hydrogen (symbol 1H) each atom has one proton, one electron, and no neutrons. In the early universe, the formation of protons, the nuclei of hydrogen, occurred during the first second after the Big Bang. The emergence of neutral hydrogen atoms throughout the universe occurred about 370,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy groups. Both the negatively charged anion , called hydroxide, and the neutral radical , known as the hydroxyl radical, consist of an unbonded hydroxy group. According to IUPAC definitions, the term ''hydroxyl'' refers to the hydroxyl radical () only, while the functional group is called a ''hydroxy group''. Properties Water, alcohols, carboxylic acids, and many other hydroxy-containing compounds can be readily deprotonated due to a large difference between the electronegativity of oxygen (3.5) and that of hydrogen (2.1). Hydroxy-containing compounds engage in intermolecular hydrogen bonding increasing the electrostatic attraction between molecules and thus to higher boiling and melting points than found for compounds that lack this f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Georg Von Georgievics
Georg Cornelius Theodor von Georgievics (18. August 1859 Weißkirchen im Banat – 26. April 1933 Znaim) was an Austria-Hungary chemist. Biography Georgievics studied at the Technical University Vienna and worked for a year in the textile company Marienthal. He continued his study with Zdenko Hans Skraup in Vienna and later with Carl Graebe at the University of Genf. From 1886 on he was assistant of Hugo Weidel at the institute for pedology (soil chemistry) in Vienna. He received his Ph.D. from the University of Gießen in 1890 and worked as lecturer at the Staatsgewerbeschulen Bielitz. He became professor at the German Charles-Ferdinand University in Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ... in 1904. His area of research was based on dyes and dyeing proce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidation
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously the oxidation state of oxygen decreases as it accepts electrons released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogenation, C=C (and other) bonds ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boric Acid
Boric acid, more specifically orthoboric acid, is a compound of boron, oxygen, and hydrogen with formula . It may also be called hydrogen borate or boracic acid. It is usually encountered as colorless crystals or a white powder, that dissolves in water, and occurs in nature as the mineral sassolite. It is a weak acid that yields various borate anions and salts, and can react with alcohols to form borate esters. Boric acid is often used as an antiseptic, insecticide, flame retardant, neutron absorber, or precursor to other boron compounds. The term "boric acid" is also used generically for any oxoacid of boron, such as metaboric acid and tetraboric acid . History Orthoboric acid was first prepared by Wilhelm Homberg (1652–1715) from borax, by the action of mineral acids, and was given the name ("sedative salt of Homberg"). However boric acid and borates have been used since the time of the ancient Greeks for cleaning, preserving food, and other activities. Molecular a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercuric Oxide
Mercury(II) oxide, also called mercuric oxide or simply mercury oxide, is the inorganic compound with the formula Mercury (element), Hgoxygen, O. It has a red or orange color. Mercury(II) oxide is a solid at room temperature and pressure. The mineral form montroydite is very rarely found. History An experiment for the preparation of mercuric oxide was first described by 11th century Arab-Spanish alchemist, Maslama al-Majriti, in ''Rutbat al-hakim.'' In 1774, Joseph Priestley discovered that oxygen was released by heating mercuric oxide, although he did not identify the gas as oxygen (rather, Priestley called it "Phlogiston, dephlogisticated air," as that was the paradigm that he was working under at the time). Synthesis The red form of HgO can be made by heating Hg in oxygen at roughly 350 °C, or by pyrolysis of mercury(II) nitrate, Hg(NO3)2. The yellow form can be obtained by precipitation of aqueous Hg2+ with alkali. The difference in color is due to particle size; b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
