142 relations: Acid dissociation constant, Adenine, Alicyclic compound, Aliphatic compound, Amino acid, Angewandte Chemie, Aniline, Annulation, Annulene, Anthracene, Antiaromaticity, Arenium ion, Aromatic amine, Aromatic hydrocarbon, Aromatic ring current, Aromatization, Aryl, Aspirin, Atomic orbital, August Kekulé, August Wilhelm von Hofmann, Avoided crossing, Azulene, Ångström, Benzene, Benzimidazole, Bond length, Borazine, Carbanion, Carbo-mer, Carbocation, Chemical compound, Chemical reaction, Chirality (chemistry), Chlorophyll, Cluster chemistry, Computational chemistry, Conjugated system, Coplanarity, Covalent bond, Cyclic compound, Cyclobutadiene, Cyclodecapentaene, Cyclooctatetraene, Cyclopentadienyl, Cyclopropenium ion, Cyclotetradecaheptaene, Cytosine, Delocalized electron, DNA, ..., Double bond, Electron, Electrophilic addition, Electrophilic aromatic substitution, Erich Clar, Erich Hückel, Functional group, Furan, Guanidine, Guanine, Handedness, Hückel's rule, Heme, Henry Edward Armstrong, Heterocyclic compound, Hexagon, Histidine, Homoaromaticity, Hund's rule of maximum multiplicity, Imidazole, J. J. Thomson, Johann Benedict Listing, Journal of Physical Chemistry A, Journal of the American Chemical Society, Journal of the Chemical Society, Liebigs Annalen, Möbius aromaticity, Möbius strip, Möbius–Hückel concept, Metal aromaticity, Molecular orbital, Molecule, Naphthalene, Nature (journal), Nuclear magnetic resonance, Nucleophilic aromatic substitution, Nucleotide, Nylon, Odor, Olfaction, Open shell, Orbital hybridisation, Organic chemistry, Organic compound, Oxazole, Paracetamol, Petrochemical, Petroleum, Phenanthrene, Phenol, Phenyl group, Phenylalanine, Pi bond, Pi interaction, Plane (geometry), Plant, Polycyclic aromatic hydrocarbon, Polyester, Polyhedral skeletal electron pair theory, Purine, Pyrazine, Pyrazole, Pyridine, Pyrimidine, Pyrrole, Quantum mechanics, Radical (chemistry), Reactivity (chemistry), Resonance (chemistry), RNA, Robert Robinson (organic chemist), Saturated and unsaturated compounds, Sigma bond, Simple aromatic ring, Single bond, Singly and doubly even, Stacking (chemistry), Styrene, Substituent, Terpene, Thiophene, Thymine, TNT, Toluene, Tropylium cation, Tryptophan, Tyrosine, Uracil, Wave, Xylene, Y-aromaticity, Zintl phase. Expand index (92 more) » « Shrink index
An acid dissociation constant, Ka, (also known as acidity constant, or acid-ionization constant) is a quantitative measure of the strength of an acid in solution.
Adenine (A, Ade) is a nucleobase (a purine derivative).
An alicyclic compound is an organic compound that is both aliphatic and cyclic.
In organic chemistry, hydrocarbons (compounds composed of carbon and hydrogen) are divided into two classes: aromatic compounds and aliphatic compounds (G. aleiphar, fat, oil) also known as non-aromatic compounds.
Amino acids are organic compounds containing amine (-NH2) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid.
Angewandte Chemie (meaning "Applied Chemistry") is a weekly peer-reviewed scientific journal that is published by Wiley-VCH on behalf of the German Chemical Society (Gesellschaft Deutscher Chemiker).
Aniline is an organic compound with the formula C6H5NH2.
In organic chemistry annulation (from the Latin anellus for "little ring"; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule.
Annulenes are completely conjugated monocyclic hydrocarbons.
Anthracene is a solid polycyclic aromatic hydrocarbon (PAH) of formula C14H10, consisting of three fused benzene rings.
Antiaromaticity is a characteristic of a cyclic molecule with a π electron system that has higher energy due to the presence of 4n electrons in it.
An arenium ion in organic chemistry is a cyclohexadienyl cation that appears as a reactive intermediate in electrophilic aromatic substitution.
An aromatic amine is an organic compound consisting of an aromatic ring attached to an amine.
An aromatic hydrocarbon or arene (or sometimes aryl hydrocarbon) is a hydrocarbon with sigma bonds and delocalized pi electrons between carbon atoms forming a circle.
An aromatic ring current is an effect observed in aromatic molecules such as benzene and naphthalene.
Aromatization is a chemical reaction in which an aromatic system is formed.
In the context of organic molecules, aryl is any functional group or substituent derived from an aromatic ring, usually an aromatic hydrocarbon, such as phenyl and naphthyl.
Aspirin, also known as acetylsalicylic acid (ASA), is a medication used to treat pain, fever, or inflammation.
In quantum mechanics, an atomic orbital is a mathematical function that describes the wave-like behavior of either one electron or a pair of electrons in an atom.
Friedrich August Kekulé, later Friedrich August Kekule von Stradonitz (7 September 1829 – 13 July 1896), was a German organic chemist.
August Wilhelm von Hofmann (8 April 18185 May 1892) was a German chemist.
In quantum physics and quantum chemistry, an avoided crossing (sometimes called intended crossing, non-crossing or anticrossing) is the phenomenon where two eigenvalues of an Hermitian matrix representing a quantum observable and depending on N continuous real parameters cannot become equal in value ("cross") except on a manifold of N-2 dimensions.
Azulene is an organic compound and an isomer of naphthalene.
The ångström or angstrom is a unit of length equal to (one ten-billionth of a metre) or 0.1 nanometre.
Benzene is an important organic chemical compound with the chemical formula C6H6.
Benzimidazole is a heterocyclic aromatic organic compound.
In molecular geometry, bond length or bond distance is the average distance between nuclei of two bonded atoms in a molecule.
Borazine is an inorganic compound with the chemical formula (BH)3(NH)3.
A carbanion is an anion in which carbon is threevalent (forms three bonds) and bears a formal negative charge in at least one significant mesomeric contributor (resonance form).
In organic chemistry, a carbo-mer (often carbo-mer or carbomer) is an expanded molecule obtained by insertion of C2 units into a given molecule.
A carbocation (/karbɔkətaɪː'jɔ̃/) is an ion with a positively charged carbon atom.
A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) composed of atoms from more than one element held together by chemical bonds.
A chemical reaction is a process that leads to the transformation of one set of chemical substances to another.
Chirality is a geometric property of some molecules and ions.
Chlorophyll (also chlorophyl) is any of several related green pigments found in cyanobacteria and the chloroplasts of algae and plants.
In chemistry, a cluster is an ensemble of bound atoms or molecules that is intermediate in size between a molecule and a bulk solid.
Computational chemistry is a branch of chemistry that uses computer simulation to assist in solving chemical problems.
In chemistry, a conjugated system is a system of connected p-orbitals with delocalized electrons in molecules which are conventionally represented as having alternating single and multiple bonds, which in general may lower the overall energy of the molecule and increase stability.
In geometry, a set of points in space are coplanar if there exists a geometric plane that contains them all.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms.
A cyclic compound (ring compound) is a term for a compound in the field of chemistry in which one or more series of atoms in the compound is connected to form a ring.
Cyclobutadiene is an organic compound with the formula 44.
Cyclodecapentaene or annulene is an annulene with molecular formula C10H10.
1,3,5,7-Cyclooctatetraene (COT) is an unsaturated derivative of cyclooctane, with the formula C8H8.
Cyclopentadienyl can refer to.
The cyclopropenium ion is the cation with the formula C3H3+.
Cyclotetradecaheptaene is a nonplanar aromatic annulene with molecular formula C14H14.
Cytosine (C) is one of the four main bases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA).
In chemistry, delocalized electrons are electrons in a molecule, ion or solid metal that are not associated with a single atom or a covalent bond.
Deoxyribonucleic acid (DNA) is a thread-like chain of nucleotides carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses.
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two.
The electron is a subatomic particle, symbol or, whose electric charge is negative one elementary charge.
In organic chemistry, an electrophilic addition reaction is an addition reaction where, in a chemical compound, a π bond is broken and two new σ bonds are formed.
Electrophilic aromatic substitution is an organic reaction in which an atom that is attached to an aromatic system (usually hydrogen) is replaced by an electrophile.
Erich Clar (August 23, 1902 – March 27, 1987) was an organic chemist who studied polycyclic aromatic hydrocarbon chemistry.
Erich Armand Arthur Joseph Hückel (August 9, 1896, Berlin – February 16, 1980, Marburg) was a German physicist and physical chemist.
In organic chemistry, functional groups are specific substituents or moieties within molecules that are responsible for the characteristic chemical reactions of those molecules.
Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen.
Guanidine is the compound with the formula HNC(NH2)2.
Guanine (or G, Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA).
In human biology, handedness is a better, faster, or more precise performance or individual preference for use of a hand, known as the dominant hand; the less capable or less preferred hand is called the non-dominant hand.
In organic chemistry, Hückel's rule estimates whether a planar ring molecule will have aromatic properties.
Heme or haem is a coordination complex "consisting of an iron ion coordinated to a porphyrin acting as a tetradentate ligand, and to one or two axial ligands." The definition is loose, and many depictions omit the axial ligands.
Henry Edward Armstrong FRS FRSE(Hon) (6 May 1848 – 13 July 1937) was an English chemist.
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).
In geometry, a hexagon (from Greek ἕξ hex, "six" and γωνία, gonía, "corner, angle") is a six-sided polygon or 6-gon.
Histidine (symbol His or H) is an α-amino acid that is used in the biosynthesis of proteins.
Homoaromaticity, in organic chemistry, refers to a special case of aromaticity in which conjugation is interrupted by a single sp3 hybridized carbon atom.
Hund's rule of maximum multiplicity is a rule based on observation of atomic spectra, which is used to predict the ground state of an atom or molecule with one or more open electronic shells.
Imidazole is an organic compound with the formula C3N2H4.
Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was an English physicist and Nobel Laureate in Physics, credited with the discovery and identification of the electron; and with the discovery of the first subatomic particle.
Johann Benedict Listing (25 July 1808 – 24 December 1882) was a German mathematician.
The Journal of Physical Chemistry A is a scientific journal which reports research on the chemistry of molecules - including their dynamics, spectroscopy, kinetics, structure, bonding, and quantum chemistry.
The Journal of the American Chemical Society (also known as JACS) is a weekly peer-reviewed scientific journal that was established in 1879 by the American Chemical Society.
The Journal of the Chemical Society was a scientific journal established by the Chemical Society in 1849 as the Quarterly Journal of the Chemical Society.
Justus Liebigs Annalen der Chemie (often cited as just Liebigs Annalen) was one of the oldest and historically most important journals in the field of organic chemistry worldwide.
In organic chemistry, Möbius aromaticity is a special type of aromaticity believed to exist in a number of organic molecules.
The Möbius strip or Möbius band, also spelled Mobius or Moebius, is a surface with only one side (when embedded in three-dimensional Euclidean space) and only one boundary.
The Möbius–Hückel treatment is one of two predicting reaction allowedness versus forbiddenness.
Metal aromaticity is the concept of aromaticity found in many organic compounds is extended to metals.
In chemistry, a molecular orbital (MO) is a mathematical function describing the wave-like behavior of an electron in a molecule.
A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.
Naphthalene is an organic compound with formula.
Nature is a British multidisciplinary scientific journal, first published on 4 November 1869.
Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a magnetic field absorb and re-emit electromagnetic radiation.
Aromatic nucleophilic substitution A nucleophilic aromatic substitution is a substitution reaction in organic chemistry in which the nucleophile displaces a good leaving group, such as a halide, on an aromatic ring.
Nucleotides are organic molecules that serve as the monomer units for forming the nucleic acid polymers deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules within all life-forms on Earth.
Nylon is a generic designation for a family of synthetic polymers, based on aliphatic or semi-aromatic polyamides.
An odor, odour or fragrance is always caused by one or more volatilized chemical compounds.
Olfaction is a chemoreception that forms the sense of smell.
In the context of atomic orbitals, an open shell is a valence shell which is not completely filled with electrons or that has not given all of its valence electrons through chemical bonds with other atoms or molecules during a chemical reaction.
In chemistry, orbital hybridisation (or hybridization) is the concept of mixing atomic orbitals into new hybrid orbitals (with different energies, shapes, etc., than the component atomic orbitals) suitable for the pairing of electrons to form chemical bonds in valence bond theory.
Organic chemistry is a chemistry subdiscipline 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.
In chemistry, an organic compound is generally any chemical compound that contains carbon.
Oxazole is the parent compound for a vast class of heterocyclic aromatic organic compounds.
--> Acetanilide was the first aniline derivative serendipitously found to possess analgesic as well as antipyretic properties, and was quickly introduced into medical practice under the name of Antifebrin by A. Cahn and P. Hepp in 1886. But its unacceptable toxic effects, the most alarming being cyanosis due to methemoglobinemia, prompted the search for less toxic aniline derivatives. Harmon Northrop Morse had already synthesised paracetamol at Johns Hopkins University via the reduction of ''p''-nitrophenol with tin in glacial acetic acid in 1877, but it was not until 1887 that clinical pharmacologist Joseph von Mering tried paracetamol on humans. In 1893, von Mering published a paper reporting on the clinical results of paracetamol with phenacetin, another aniline derivative. Von Mering claimed that, unlike phenacetin, paracetamol had a slight tendency to produce methemoglobinemia. Paracetamol was then quickly discarded in favor of phenacetin. The sales of phenacetin established Bayer as a leading pharmaceutical company. Overshadowed in part by aspirin, introduced into medicine by Heinrich Dreser in 1899, phenacetin was popular for many decades, particularly in widely advertised over-the-counter "headache mixtures", usually containing phenacetin, an aminopyrine derivative of aspirin, caffeine, and sometimes a barbiturate. Paracetamol is the active metabolite of phenacetin and acetanilide, both once popular as analgesics and antipyretics in their own right. However, unlike phenacetin, acetanilide and their combinations, paracetamol is not considered carcinogenic at therapeutic doses. Von Mering's claims remained essentially unchallenged for half a century, until two teams of researchers from the United States analyzed the metabolism of acetanilide and paracetamol. In 1947 David Lester and Leon Greenberg found strong evidence that paracetamol was a major metabolite of acetanilide in human blood, and in a subsequent study they reported that large doses of paracetamol given to albino rats did not cause methemoglobinemia. In three papers published in the September 1948 issue of the Journal of Pharmacology and Experimental Therapeutics, Bernard Brodie, Julius Axelrod and Frederick Flinn confirmed using more specific methods that paracetamol was the major metabolite of acetanilide in human blood, and established that it was just as efficacious an analgesic as its precursor. They also suggested that methemoglobinemia is produced in humans mainly by another metabolite, phenylhydroxylamine. A follow-up paper by Brodie and Axelrod in 1949 established that phenacetin was also metabolised to paracetamol. This led to a "rediscovery" of paracetamol. It has been suggested that contamination of paracetamol with 4-aminophenol, the substance von Mering synthesised it from, may be the cause for his spurious findings. Paracetamol was first marketed in the United States in 1950 under the name Triagesic, a combination of paracetamol, aspirin, and caffeine. Reports in 1951 of three users stricken with the blood disease agranulocytosis led to its removal from the marketplace, and it took several years until it became clear that the disease was unconnected. Paracetamol was marketed in 1953 by Sterling-Winthrop Co. as Panadol, available only by prescription, and promoted as preferable to aspirin since it was safe for children and people with ulcers. In 1955, paracetamol was marketed as Children's Tylenol Elixir by McNeil Laboratories. In 1956, 500 mg tablets of paracetamol went on sale in the United Kingdom under the trade name Panadol, produced by Frederick Stearns & Co, a subsidiary of Sterling Drug Inc. In 1963, paracetamol was added to the British Pharmacopoeia, and has gained popularity since then as an analgesic agent with few side-effects and little interaction with other pharmaceutical agents. Concerns about paracetamol's safety delayed its widespread acceptance until the 1970s, but in the 1980s paracetamol sales exceeded those of aspirin in many countries, including the United Kingdom. This was accompanied by the commercial demise of phenacetin, blamed as the cause of analgesic nephropathy and hematological toxicity. In 1988 Sterling Winthrop was acquired by Eastman Kodak which sold the over the counter drug rights to SmithKline Beecham in 1994. Available without a prescription since 1959, it has since become a common household drug. Patents on paracetamol have long expired, and generic versions of the drug are widely available.
Petrochemicals (also known as petroleum distillates) are chemical products derived from petroleum.
Petroleum is a naturally occurring, yellow-to-black liquid found in geological formations beneath the Earth's surface.
Phenanthrene is a polycyclic aromatic hydrocarbon composed of three fused benzene rings.
Phenol, also known as phenolic acid, is an aromatic organic compound with the molecular formula C6H5OH.
In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C6H5.
Phenylalanine (symbol Phe or F) is an α-amino acid with the formula.
In chemistry, pi bonds (π bonds) are covalent chemical bonds where two lobes of an orbital on one atom overlap two lobes of an orbital on another atom.
In chemistry, π-effects or π-interactions are a type of non-covalent interaction that involves π systems.
In mathematics, a plane is a flat, two-dimensional surface that extends infinitely far.
Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae.
Polycyclic aromatic hydrocarbons (PAHs, also polyaromatic hydrocarbons or polynuclear aromatic hydrocarbons) are hydrocarbons—organic compounds containing only carbon and hydrogen—that are composed of multiple aromatic rings (organic rings in which the electrons are delocalized).
Polyester is a category of polymers that contain the ester functional group in their main chain.
In chemistry the polyhedral skeletal electron pair theory (PSEPT) provides electron counting rules useful for predicting the structures of clusters such as borane and carborane clusters.
A purine is a heterocyclic aromatic organic compound that consists of a pyrimidine ring fused to an imidazole ring.
Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C4H4N2.
Pyrazole is an organic compound with the formula C3H3N2H.
Pyridine is a basic heterocyclic organic compound with the chemical formula C5H5N.
Pyrimidine is an aromatic heterocyclic organic compound similar to pyridine.
Pyrrole is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H4NH.
Quantum mechanics (QM; also known as quantum physics, quantum theory, the wave mechanical model, or matrix mechanics), including quantum field theory, is a fundamental theory in physics which describes nature at the smallest scales of energy levels of atoms and subatomic particles.
In chemistry, a radical (more precisely, a free radical) is an atom, molecule, or ion that has an unpaired valence electron.
In chemistry, reactivity is the impetus for which a chemical substance undergoes a chemical reaction, either by itself or with other materials, with an overall release of energy.
In chemistry, resonance or mesomerism is a way of describing delocalized electrons within certain molecules or polyatomic ions where the bonding cannot be expressed by one single Lewis structure.
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes.
Sir Robert Robinson (13 September 1886 – 8 February 1975) was a British organic chemist and Nobel laureate recognised in 1947 for his research on plant dyestuffs (anthocyanins) and alkaloids.
In organic chemistry, a saturated compound is a chemical compound that has single bonds.
In chemistry, sigma bonds (σ bonds) are the strongest type of covalent chemical bond.
Simple aromatic rings, also known as simple arenes or simple aromatics, are aromatic organic compounds that consist only of a conjugated planar ring system.
In chemistry, a single bond is a chemical bond between two atoms involving two valence electrons.
In mathematics an even integer, that is, a number that is divisible by 2, is called evenly even or doubly even if it is a multiple of 4, and oddly even or singly even if it is not.
In chemistry, pi stacking (also called π–π stacking) refers to attractive, noncovalent interactions between aromatic rings, since they contain pi bonds.
Styrene, also known as ethenylbenzene, vinylbenzene, and phenylethene, is an organic compound with the chemical formula C6H5CH.
In organic chemistry and biochemistry, a substituent is an atom or group of atoms which replaces one or more hydrogen atoms on the parent chain of a hydrocarbon, becoming a moiety of the resultant new molecule.
Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, and by some insects.
Thiophene is a heterocyclic compound with the formula C4H4S.
---> Thymine (T, Thy) is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T.
Trinitrotoluene (TNT), or more specifically 2,4,6-trinitrotoluene, is a chemical compound with the formula C6H2(NO2)3CH3.
Toluene, also known as toluol, is an aromatic hydrocarbon.
In organic chemistry, the tropylium ion is an aromatic species with a formula of +. Its name derives from the molecule tropine (itself named for the molecule atropine).
Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins.
Tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins.
Uracil (U) is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine (A), cytosine (C), and guanine (G).
In physics, a wave is a disturbance that transfers energy through matter or space, with little or no associated mass transport.
Xylene (from Greek ξύλο, xylo, "wood"), xylol or dimethylbenzene is any one of three isomers of dimethylbenzene, or a combination thereof.
In organic chemistry, the term Y-aromaticity is used to describe a Y-shaped, planar (flat) molecule with resonance bonds that exhibits more stability than other geometric or connective arrangements with the same set of atoms.
In chemistry, a Zintl phase is the product of a reaction between a group 1 (alkali metal) or group 2 (alkaline earth) and any post-transition metal or metalloid (i.e. from group 13, 14, 15 or 16).
Aromacity, Aromate, Aromatic, Aromatic (chemistry), Aromatic Compound, Aromatic Compounds, Aromatic chemical, Aromatic chemical compound, Aromatic compound, Aromatic compounds, Aromatic molecule, Aromatic ring, Aromatic rings, Aromatics, Aza-arene, Heteroaromatic, Kekule structure, Kekulé Structures, Kekulé structure, Non-aromatic, Nonaromatic, Nonaromaticity.