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Glycoluril
Glycoluril is an organic chemical composed of two cyclic urea groups joined across the same two-carbon chain. It is a white powder that has been used in water treatment, in paints and coatings, and occasionally as a slow-release fertilizer. Production Glycoluril can be synthesized by reacting two equivalents of urea with glyoxal. Likewise, using other vicinal (chemistry), vicinal diketone, carbonyl (or ketone hydrate, carbonyl hydrate) reactants give derivatives having various functional groups in place of the hydrogen atoms on the carbon chain. Properties The four amide-like and therefore acidic hydrogen atoms of glycoluril are amenable to a variety of chemical reactions, such as substitution with halogen atoms or a reaction with formaldehyde. Use Glycouril itself and derivatives of it are used as monomers for producing the macrocyclic cucurbiturils polymers, which serve as hosts to bind to various neutral and cationic species. They are also used in several classes of non-cycl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cucurbituril
In host-guest chemistry, cucurbiturils are macrocyclic molecules made of glycoluril () monomers linked by methylene bridges (). The oxygen atoms are located along the edges of the band and are tilted inwards, forming a partly enclosed cavity (cavitand). The name is derived from the resemblance of this molecule with a pumpkin of the family of Cucurbitaceae. Cucurbiturils are commonly written as cucurbit 'n''ril, where ''n'' is the number of glycoluril units. Two common abbreviations are CB 'n'''', or simply CB''n''. These compounds are particularly interesting to chemists because they are suitable hosts for an array of neutral and cationic species. The binding mode is thought to occur through hydrophobic interactions, and, in the case of cationic guests, through cation-dipole interactions as well. The dimensions of cucurbiturils are generally on the ~10 Å size scale. For instance, the cavity of cucurbit ril has a height ~9.1 Å, an outer diameter ~5.8 Å, and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitroglycoluril
Dinitroglycoluril (DINGU) is a high explosive chemical compound with the formula C4 H4 N6 O6. Dinitroglycoluril is of growing interest due to its stability, ability to mix with oxygen positive explosives to form composites, and it is a precursor to tetranitroglycoluril. Preparation and decomposition Dinitroglycoluril can be created by nitrating glycoluril with concentrated nitric acid. : The activation energy required to begin decomposition of dinitroglycoluril is 165 kJ/mol. When dinitroglycoluril is heated to 243 °C in an inert atmosphere, the two nitrate Nitrate is a polyatomic ion A polyatomic ion, also known as a molecular ion, is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that has a net charge that is not zer ... groups break off and the two central carbon atoms form a double bond. Sensitivity The impact sensitivity of dinitroglycoluril was determined using the Bruc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemical
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 thing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soil Science And Plant Nutrition
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid phase of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three- state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists regard soil as an eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Percarbonate
Sodium percarbonate is a chemical substance with formula . It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 · 3 . It is a colorless, crystalline, hygroscopic and water-soluble solid. It is sometimes abbreviated as SPC. It contains 32.5% by weight of hydrogen peroxide. The product is used in some eco-friendly bleaches and other cleaning products itation needed History Sodium percarbonate was first prepared in 1899 by Russian chemist Sebastian Moiseevich Tanatar (7 October 1849 – 30 November 1917). Structure At room temperature, solid sodium percarbonate has the orthorhombic crystal structure, with the ''Cmca'' crystallographic space group. The structure changes to ''Pbca'' as the crystals are cooled below about −30 °C. Chemistry Dissolved in water, sodium percarbonate yields a mixture of hydrogen peroxide (which eventually decomposes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetic Anhydride
Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula (CH3CO)2O. Commonly abbreviated Ac2O, it is the simplest isolable anhydride of a carboxylic acid and is widely used as a reagent in organic synthesis. It is a colorless liquid that smells strongly of acetic acid, which is formed by its reaction with moisture in the air. Structure and properties Acetic anhydride, like most acid anhydrides, is a flexible molecule with a nonplanar structure. The pi system linkage through the central oxygen offers very weak resonance stabilization compared to the dipole-dipole repulsion between the two carbonyl oxygens. The energy barriers to bond rotation between each of the optimal aplanar conformations are quite low. Like most acid anhydrides, the carbonyl carbon atom of acetic anhydride has electrophilic character, as the leaving group is carboxylate. The internal asymmetry may contribute to acetic anhydride's potent electrophilicity as the asymmetric geometry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fungicide
Fungicides are biocidal chemical compounds or biological organisms used to kill parasitic fungi or their spores. A fungistatic inhibits their growth. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Chemicals used to control oomycetes, which are not fungi, are also referred to as fungicides, as oomycetes use the same mechanisms as fungi to infect plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upwardly. Most fungicides that can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methanal
Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section Forms below), hence it is stored as an aqueous solution (formalin), which is also used to store animal specimens. It is the simplest of the aldehydes (). The common name of this substance comes from its similarity and relation to formic acid. Formaldehyde is an important precursor to many other materials and chemical compounds. In 1996, the installed capacity for the production of formaldehyde was estimated at 8.7 million tons per year. It is mainly used in the production of industrial resins, e.g., for particle board and coatings. Forms Formaldehyde is more complicated than many simple carbon compounds in that it adopts several diverse forms. These compounds can often be used interchangeably and can be interconverted. *Molecular formal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biocide
A biocide is defined in the European legislation as a chemical substance or microorganism intended to destroy, deter, render harmless, or exert a controlling effect on any harmful organism. The US Environmental Protection Agency (EPA) uses a slightly different definition for biocides as "a diverse group of poisonous substances including preservatives, insecticides, disinfectants, and pesticides used for the control of organisms that are harmful to human or animal health or that cause damage to natural or manufactured products". When compared, the two definitions roughly imply the same, although the US EPA definition includes plant protection products and some veterinary medicines. The terms "biocides" and "pesticides" are regularly interchanged, and often confused with "plant protection products". To clarify this, pesticides include both biocides and plant protection products, where the former refers to substances for non-food and feed purposes and the latter refers to substances ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urea
Urea, also known as carbamide, is an organic compound with chemical formula . This amide has two amino groups (–) joined by a carbonyl functional group (–C(=O)–). It is thus the simplest amide of carbamic acid. Urea serves an important role in the metabolism of nitrogen-containing compounds by animals and is the main nitrogen-containing substance in the urine of mammals. It is a colorless, odorless solid, highly soluble in water, and practically non-toxic ( is 15 g/kg for rats). Dissolved in water, it is neither acidic nor alkaline. The body uses it in many processes, most notably nitrogen excretion. The liver forms it by combining two ammonia molecules () with a carbon dioxide () molecule in the urea cycle. Urea is widely used in fertilizers as a source of nitrogen (N) and is an important raw material for the chemical industry. In 1828 Friedrich Wöhler discovered that urea can be produced from inorganic starting materials, which was an important conceptual milestone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
