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Cryptophane
Cryptophanes are a class of organic supramolecular compounds studied and synthesized primarily for molecular encapsulation and recognition. One possible noteworthy application of cryptophanes is encapsulation and storage of hydrogen gas for potential use in fuel cell automobiles. Cryptophanes can also serve as containers in which organic chemists can carry out reactions that would otherwise be difficult to run under normal conditions. Due to their unique molecular recognition properties, cryptophanes also hold great promise as a potentially new way to study the binding of organic molecules with substrates, particularly as pertaining to biological and biochemical applications. Discovery Cryptophanes were discovered by AndrĂ© Collet and Jacqueline Gabard in 1981 when these researchers created, using template-directed synthesis, the first cryptophane, now known as cryptophane-A. Structure Cryptophane cages are formed by two cup-shaped .1.1€“ortho cyclophane units (see cyclotri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cryptophane General Structure
Cryptophanes are a class of organic supramolecular compounds studied and synthesized primarily for molecular encapsulation and recognition. One possible noteworthy application of cryptophanes is encapsulation and storage of hydrogen gas for potential use in fuel cell automobiles. Cryptophanes can also serve as containers in which organic chemists can carry out reactions that would otherwise be difficult to run under normal conditions. Due to their unique molecular recognition properties, cryptophanes also hold great promise as a potentially new way to study the binding of organic molecules with substrates, particularly as pertaining to biological and biochemical applications. Discovery Cryptophanes were discovered by AndrĂ© Collet and Jacqueline Gabard in 1981 when these researchers created, using template-directed synthesis, the first cryptophane, now known as cryptophane-A. Structure Cryptophane cages are formed by two cup-shaped .1.1€“orthocyclophane units (see cyclotrivera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclotriveratrylene
Cyclotriveratrylene (CTV) is an organic compound with the formula [C6H2(OCH3)2CH2]3. It is a white solid that is soluble in organic solvents. The compound is a macrocycle and used in host–guest chemistry as a molecular host. Synthesis The compound can be synthesised from veratrole alcohol upon acid catalysis. : Operating via the same intermediates, an alternative synthesis involves the acid-catalyzed reaction of veratrole and formaldehyde. The method is similar to the reactions that give phenol formaldehyde resins except that the degree of polymerization is moderated by the methoxy substituents. Host–guest behavior CTV has a bowl shaped conformation, giving the molecule C3 symmetry. The ether groups are situated at the upper rim, but in contrast a crown ether typically do not interact with guests. The compound is related to calixarenes in terms of its host–guest properties and its synthesis CTV derivates are known to bind fullerenes and the use of CTV's in the separa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Royal Society Of Chemistry
The Royal Society of Chemistry (RSC) is a learned society and professional association in the United Kingdom with the goal of "advancing the chemistry, chemical sciences". It was formed in 1980 from the amalgamation of the Chemical Society, the Royal Institute of Chemistry, the Faraday Society, and the Society for Analytical Chemistry with a new Royal Charter and the dual role of learned society and professional body. At its inception, the Society had a combined membership of 49,000 in the world. The headquarters of the Society are at Burlington House, Piccadilly, London. It also has offices in Thomas Graham House in Cambridge (named after Thomas Graham (chemist), Thomas Graham, the first president of the Chemical Society) where ''RSC Publishing'' is based. The Society has offices in the United States, on the campuses of The University of Pennsylvania and Drexel University, at the University City Science Center in Philadelphia, Pennsylvania, in both Beijing and Shanghai, People' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Deuterium
Deuterium (hydrogen-2, symbol H or D, also known as heavy hydrogen) is one of two stable isotopes of hydrogen; the other is protium, or hydrogen-1, H. The deuterium nucleus (deuteron) contains one proton and one neutron, whereas the far more common H has no neutrons. The name ''deuterium'' comes from Greek '' deuteros'', meaning "second". American chemist Harold Urey discovered deuterium in 1931. Urey and others produced samples of heavy water in which the H had been highly concentrated. The discovery of deuterium won Urey a Nobel Prize in 1934. Nearly all deuterium found in nature was synthesized in the Big Bang 13.8 billion years ago, forming the primordial ratio of H to H (~26 deuterium nuclei per 10 hydrogen nuclei). Deuterium is subsequently produced by the slow stellar proton–proton chain, but rapidly destroyed by exothermic fusion reactions. The deuterium–deuterium reaction has the second-lowest energy threshold, and is the most astrophysically acce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the chemical formula, formula , called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas (dihydrogen) and in molecular forms, such as in water and organic compounds. The most common isotope of hydrogen (H) consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Symmetry
Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant under some Transformation (function), transformations, such as Translation (geometry), translation, Reflection (mathematics), reflection, Rotation (mathematics), rotation, or Scaling (geometry), scaling. Although these two meanings of the word can sometimes be told apart, they are intricately related, and hence are discussed together in this article. Mathematical symmetry may be observed with respect to the passage of time; as a space, spatial relationship; through geometric transformations; through other kinds of functional transformations; and as an aspect of abstract objects, including scientific model, theoretic models, language, and music. This article describes symmetry from three perspectives: in mathematics, including geometry, the m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Diastereomer
In stereochemistry, diastereomers (sometimes called diastereoisomers) are a type of stereoisomer. Diastereomers are defined as non-mirror image, non-identical stereoisomers. Hence, they occur when two or more stereoisomers of a compound have different configurations at one or more (but not all) of the equivalent (related) stereocenters and are not mirror images of each other. When two diastereoisomers differ from each other at only one stereocenter, they are epimers. Each stereocenter gives rise to two different configurations and thus typically increases the number of stereoisomers by a factor of two. Diastereomers differ from enantiomers in that the latter are pairs of stereoisomers that differ in all stereocenters and are therefore mirror images of one another. Enantiomers of a compound with more than one stereocenter are also diastereomers of the other stereoisomers of that compound that are not their mirror image (that is, excluding the opposing enantiomer). Diastereomers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
CRC Press
The CRC Press, LLC is an American publishing group that specializes in producing technical books. Many of their books relate to engineering, science and mathematics. Their scope also includes books on business, forensics and information technology. CRC Press is now a division of Taylor & Francis, itself a subsidiary of Informa. History The CRC Press was founded as the Chemical Rubber Company (CRC) in 1903 by brothers Arthur, Leo and Emanuel Friedman in Cleveland, Ohio, based on an earlier enterprise by Arthur, who had begun selling rubber laboratory aprons in 1900. The company gradually expanded to include sales of laboratory equipment to chemist A chemist (from Greek ''chÄ“m(Ăa)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...s. In 1913 the CRC offered a short (116-page) manual called the ''Rubber Handboo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cyclophane
In organic chemistry, a cyclophane is a hydrocarbon consisting of an aromatic unit (typically a benzene ring) and a Catenation, chain that forms a bridge (chemical), bridge between two non-adjacent positions of the aromatic ring. More complex derivatives with multiple aromatic units and bridges forming cagelike structures are also known. Cyclophanes are well-studied examples of Strain (chemistry), strained organic compounds. [n]-Cyclophanes Structures Paracyclophanes adopt the boat conformation normally observed in cyclohexanes. Smaller value of n lead to greater distortions. X-ray crystallography on '[6]paracyclophane' shows that the aromatic bridgehead carbon atom makes an angle of 20.5° with the plane. The benzyl carbons deviate by another 20.2°. The carbon-to-carbon bond length alternation has increased from 0 for benzene to 39 picometer, pm. Despite their distorted structures, cyclophanes retain their aromaticity, as determined by UV-vis spectroscopy. Reactivity With re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
André Collet
André — sometimes transliterated as Andre — is the French and Portuguese language, Portuguese form of the name Andrew and is now also used in the English-speaking world. It used in France, Quebec, Canada and other French language, French-speaking countries, as well in Portugal, Brazil and other Portuguese-speaking countries. It is a variation of the Greek language, Greek name ''Andreas'', a short form of any of various compound names derived from ''andr-'' 'man, warrior'. The name is popular in Norway and Sweden. Cognate names Cognate names are: * Bulgarian language, Bulgarian: Andrei, Andrey * Breton language, Breton : Andrev ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
