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Diazapentalene
In organic chemistry, a diazapentalene is any of the heterocyclic compounds having molecular formula C6H6N2 whose structure is two fused two pentagonal rings of six carbon atoms and two nitrogen atoms. That is, it is a heteropentalene, with two nitrogens substituted in for carbons. There are several different constitutional isomers. Each diazapentalene has 10 pi electrons and shows aromaticity. Some of the diazapentalenes are mesomeric betaines, however these diazapentalenes are not mesoionic. See also *pentalene *Diketopyrrolopyrrole dye Diketopyrrolopyrroles (DPPs) are organic dyes and pigments based on the heterocyclic dilactam 2,5-dihydropyrrolo ,4-''c''yrrole-1,4-dione, widely used in optoelectronics. DPPs were initially used as pigments in the painting industry (e.g. in automo ...( :de:Diketopyrrolopyrrol-Pigmente) References {{reflist Heterocyclic compounds with 2 rings Simple aromatic rings Nitrogen heterocycles ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteropentalene
Heteropentalenes are class of heterocyclic compound. Heteropentalenes have one, two or more heteroatoms on the ring. It consists of two pentagonal rings. Heteropentalenes with 10 pi electrons show aromaticity. Some of heteropentalenes are mesomeric betaines. However those heteropentalenes are not mesoionic See also *Benzimidazole * Diazapentalene *Indole *Mesomeric betaine Mesomeric betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes (e.g. diazapentalenes). Heteropentalenes are not mesoionic In ch ... * Trithiapentalene References {{Reflist Heterocyclic compounds with 2 rings Simple aromatic rings ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Chemistry
Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, and reactions of organic compounds and organic materials, i.e., matter in its various forms that contain carbon atoms.Clayden, J.; Greeves, N. and Warren, S. (2012) ''Organic Chemistry''. Oxford University Press. pp. 1–15. . Study of structure determines their structural formula. Study of properties includes physical and chemical properties, and evaluation of chemical reactivity to understand their behavior. The study of organic reactions includes the chemical synthesis of natural products, drugs, and polymers, and study of individual organic molecules in the laboratory and via theoretical ( in silico) study. The range of chemicals studied in organic chemistry includes hydrocarbons (compounds containing only carbon and hydrogen) as well as compounds based on carbon, but also containing other elements, especially oxygen, nitrogen, sulfur, phosphorus (included in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compound
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include subscripts and superscripts. A chemical formula is not a chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers indicating the numerical ''proportions'' of atoms o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constitutional Isomer
In chemistry, a structural isomer (or constitutional isomer in the IUPAC nomenclature) of a chemical compound, compound is another compound whose molecule has the same number of atoms of each element, but with logically distinct chemical bond, bonds between them. The term metamer was formerly used for the same concept. For example, butanol , methyl propyl ether , and diethyl ether have the same molecular formula but are three distinct structural isomers. The concept applies also to polyatomic ions with the same total charge. A classical example is the cyanate ion and the fulminate ion . It is also extended to ionic compounds, so that (for example) ammonium cyanate and urea are considered structural isomers,William F. Bynum, E. Janet Browne, Roy Porter (2014): ''Dictionary of the History of Science''. 530 pages. and so are methylammonium formate and ammonium acetate . Structural isomerism is the most radical type of isomerism. It is opposed to stereoisomerism, in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Electron
In chemistry, pi bonds (π bonds) are covalent chemical bonds, in each of which two lobes of an orbital on one atom overlap with two lobes of an orbital on another atom, and in which this overlap occurs laterally. Each of these atomic orbitals has an electron density of zero at a shared nodal plane that passes through the two bonded nuclei. This plane also is a nodal plane for the molecular orbital of the pi bond. Pi bonds can form in double and triple bonds but do not form in single bonds in most cases. The Greek letter π in their name refers to p orbitals, since the orbital symmetry of the pi bond is the same as that of the p orbital when seen down the bond axis. One common form of this sort of bonding involves p orbitals themselves, though d orbitals also engage in pi bonding. This latter mode forms part of the basis for metal-metal multiple bonding. Pi bonds are usually weaker than sigma bonds. The C-C double bond, composed of one sigma and one pi bond, has a bond ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesomeric Betaine
Mesomeric betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes (e.g. diazapentalenes). Heteropentalenes are not mesoionic In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be rep .... References {{reflist Heterocyclic compounds Aromatic compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesoionic
In chemistry, mesoionic compounds are one in which a heterocyclic structure is dipolar and where both the negative and the positive charges are delocalized. A completely uncharged structure cannot be written and mesoionic compounds cannot be represented satisfactorily by any one mesomeric structure. Mesoionic compounds are a subclass of betaines. Examples are sydnones and sydnone imines (e.g. the stimulant mesocarb), münchnones, and mesoionic carbenes. The formal positive charge is associated with the ring atoms and the formal negative charge is associated either with ring atoms or an exocyclic nitrogen or other atom. These compounds are stable zwitterionic compounds and belong to nonbenzenoid aromatics. See also * Mesomeric betaine Mesomeric betaines are dipolar heterocyclic compounds in which both the negative and the positive charges are delocalized. Examples are mesoionic compounds and heteropentalenes (e.g. diazapentalenes). Heteropentalenes are not mesoionic In c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentalene
Pentalene is a polycyclic hydrocarbon composed of two fused cyclopentadiene rings. It has chemical formula . It is antiaromatic, because it has 4''n'' π electrons where ''n'' is any integer. For this reason it dimerizes even at temperatures as low as −100 °C. The derivative 1,3,5-tri-''tert''-butylpentalene was synthesized in 1973. Because of the ''tert''-butyl substituents this compound is thermally stable. Pentalenes can also be stabilized by benzannulation for example in the compounds benzopentalene and dibenzopentalene. Dilithium pentalenide was isolated in 1962, long before pentalene itself in 1997. It is prepared from reaction of dihydropentalene (pyrolysis of an isomer of dicyclopentadiene) with ''n''-butyllithium in solution and forms a stable salt. In accordance with its structure proton NMR shows 2 signals in a 2 to 1 ratio. The addition of two electrons removes the antiaromaticity; it becomes a planar 10π-electron aromatic species and is thus a bicyclic a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diketopyrrolopyrrole Dye
Diketopyrrolopyrroles (DPPs) are organic dyes and pigments based on the heterocyclic dilactam 2,5-dihydropyrrolo ,4-''c''yrrole-1,4-dione, widely used in optoelectronics. DPPs were initially used as pigments in the painting industry (e.g. in automotive paints) due to their high resistance to photodegradation. More recently, DPP derivatives have been also investigated as promising fluorescent dyes for bioimaging applications, as well as components of materials for use in organic electronics. Structure DPP dyes are based on the bicyclic heterocyclic compound diketopyrrolopyrrole. 2,5-Dihydropyrrolo ,4-cyrrol-1,4-dion is a basic body of Diketopyrrolopyrrole dye. DPP pigments are an important class of high-performance pigments used in inks, paints and plastic. More recently their optical-electronic performance was discovered for photovoltaic applications and related uses. Optical properties DPP has high stability to heat but not very well to acid and base. The alkylation of am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterocyclic Compounds With 2 Rings
A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic chemistry is the branch of organic chemistry dealing with the synthesis, properties, and applications of these heterocycles. Examples of heterocyclic compounds include all of the nucleic acids, the majority of drugs, most biomass (cellulose and related materials), and many natural and synthetic dyes. More than half of known compounds are heterocycles. 59% of US FDA-approved drugs contain nitrogen heterocycles. Classification The study of heterocyclic chemistry focuses especially on unsaturated derivatives, and the preponderance of work and applications involves unstrained 5- and 6-membered rings. Included are pyridine, thiophene, pyrrole, and furan. Another large class of heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
