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Philippe Barbier
Philippe Antoine Francoise Barbier (2 March 1848 – 18 September 1922) was a French organic chemist. He is best known for his two named reactions in organic synthesis, the Barbier reaction and the Barbier-Wieland degradation, as well as for his role in the creation of organomagnesium reagents with his student, Victor Grignard. Although Grignard was awarded the Nobel prize in 1912 (along with Sabatier) for his discovery, Barbier and Sabatier’s collaborator, Senderens, were snubbed. Grignard himself decried this as an injustice, writing to a friend just days after returning from his Nobel acceptance: “…to tell the truth, and between us, I would even have preferred to wait a little longer, to see the prize shared between Sabatier and Senderens, and then share it myself with Barbier at a later time”. Nevertheless, Barbier’s contributions to the scientific community were plentiful and varied, including work in mineralogy, natural products isolation, and polycyclic aromat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portrait Of Philippe Barbier
A portrait is a painting Painting is the practice of applying paint, pigment, color or other medium to a solid surface (called the "matrix" or "support"). The medium is commonly applied to the base with a brush, but other implements, such as knives, sponges, and ..., portrait photography, photograph, sculpture, or other artistic representation of a person, in which the face and its expressions are predominant. The intent is to display the likeness, Personality type, personality, and even the mood of the person. For this reason, in photography a portrait is generally not a Snapshot (photography), snapshot, but a composed image of a person in a still position. A portrait often shows a person looking directly at the painter or photographer, in order to most successfully engage the subject with the viewer. History Prehistorical portraiture Plastered human skulls were reconstructed human skulls that were made in the ancient Levant between 9000 and 6000 BC in the Pre-Potte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C14H10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics and pesticides, explosives and drugs. It has also been used to make bile acids, cholesterol and steroids. Phenanthrene occurs naturally and also is a man-made chemical. Commonly, humans are exposed to phenanthrene through inhalation of cigarette smoke but there are many routes of exposure. Animal studies have shown that phenanthrene is a potential carcinogen. However, according to IARC, it is not identified as a probable, possible or confirmed human carcinogen. Phenanthrene's three fused rings are angled as in the phenacenes, rather than straight as in the acenes. The compound with a phenanthrene skeleton and nitrogens at the 4 and 5 positions is known as phenanthroline. Chemistry Phenanthrene is nearly insoluble in water but is soluble in most low pola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citronellol
Citronellol, or dihydrogeraniol, is a natural acyclic monoterpenoid. Both enantiomers occur in nature. (+)-Citronellol, which is found in citronella oils, including ''Cymbopogon nardus'' (50%), is the more common isomer. (−)-Citronellol is widespread, but particularly abundant in the oils of rose (18–55%) and ''Pelargonium'' geraniums. Preparation Several million kilograms of citronellol are produced annually. It is mainly obtained by hydrogenation of geraniol or nerol over copper chromite catalyst. Homogeneous catalysts are used for the production of enantiomers. Citronellene is also a precursor. Uses Citronellol is used in perfumes and as a fragrance in cleaning products. In many applications, one of the enantiomers is preferred. It is a component of citronella oil, an insect repellant. Citronellol is used as a raw material for the production of rose oxide. It is also a precursor to many commercial and potential fragrances such as citronellol acetate, citronellyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linalool
Linalool () refers to two enantiomers of a naturally occurring terpene alcohol found in many flowers and spice plants. Linalool has multiple commercial applications, the majority of which are based on its pleasant scent (floral, with a touch of spiciness). A colorless oil, linalool is classified as an acyclic monoterpenoid. In plants, it is a metabolite, a volatile oil component, an antimicrobial agent, and an aroma compound. Linalool has uses in manufacturing of soaps, fragrances, food additives as flavors, household products, and insecticides. Esters of linalool are referred to as linalyl, e.g. linalyl pyrophosphate, an isomer of geranyl pyrophosphate. The word ''linalool'' is based on '' linaloe'' (a type of wood) and the suffix '. In food manufacturing, it may be called ''coriandrol''. Occurrence Both enantiomeric forms are found in nature: (''S'')-linalool is found, for example, as a major constituent of the essential oils of coriander (''Coriandrum sativum'' L.), cymbopo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Citral
Citral is an acyclic monoterpene aldehyde, and being a monoterpene, it is made of two isoprene units. Citral is a collective term which covers two geometric isomers that have their own separate names; the ''E''-isomer is named geranial (''trans''-citral) or citral A. The ''Z''-isomer is named neral (''cis''-citral) or citral B. These stereoisomers occur as a mixture, not necessarily racemic; e.g. in essential oil of Australian ginger, the neral to geranial ratio is 0.61. Occurrence Citral is present in the oils of several plants, including lemon myrtle (90–98%), '' Litsea citrata'' (90%), ''Litsea cubeba'' (70–85%), lemongrass (65–85%), lemon tea-tree (70–80%), ''Ocimum gratissimum'' (66.5%), '' Lindera citriodora'' (about 65%), '' Calypranthes parriculata'' (about 62%), petitgrain (36%), lemon verbena (30–35%), lemon ironbark (26%), lemon balm (11%), lime (6–9%), lemon (2–5%), and orange. Further, in the lipid fraction (essential oil) of Australian ginger (51- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myrcenol
Myrcenol is an organic compound, specifically a terpenoid. It is most notable as one of the fragrant components of lavender oil. It is also found in the hop plant (''Humulus lupulus''). E-Myrcenol acts also as a pheromone for bark beetles. Role in fragrance industry Myrcenol is obtained synthetically from myrcene via hydroamination of the 1,3-diene followed by hydrolysis and Pd-catalysed removal of the amine. As a 1,3-diene, myrcenol undergoes Diels-Alder reactions with several dienophiles such as acrolein Acrolein (systematic name: propenal) is the simplest unsaturated aldehyde. It is a colorless liquid with a piercing, acrid smell. The smell of burnt fat (as when cooking oil is heated to its smoke point) is caused by glycerol in the burning fa ... to give cyclohexene derivatives that are also useful fragrances.Karl-Georg Fahlbusch, Franz-Josef Hammerschmidt, Johannes Panten, Wilhelm Pickenhagen, Dietmar Schatkowski, Kurt Bauer, Dorothea Garbe, Horst Surburg "Flavors and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantitative Analysis (chemistry)
In analytical chemistry, quantitative analysis is the determination of the absolute or relative abundance (often expressed as a concentration) of one, several or all particular substance(s) present in a sample. Methods Once the presence of certain substances in a sample is known, the study of their absolute or relative abundance could help in determining specific properties. Knowing the composition of a sample is very important, and several ways have been developed to make it possible, like gravimetric and volumetric analysis. Gravimetric analysis yields more accurate data about the composition of a sample than volumetric analysis but also takes more time to perform in the laboratory. Volumetric analysis, on the other hand, doesn't take that much time and can produce satisfactory results. Volumetric analysis can be simply a titration based in a neutralization reaction but it can also be a precipitation or a complex forming reaction as well as a titration based in a redox reactio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elemental Analysis
Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compounds) is analyzed for its elemental and sometimes isotopic composition. Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative (determining how much of each is present). Elemental analysis falls within the ambit of analytical chemistry, the instruments involved in deciphering the chemical nature of our world. History Antoine Lavoisier is regarded as the inventor of elemental analysis as a quantitative, experimental tool to assess the chemical composition of a compound. At the time, elemental analysis was based on the gravimetric determination of specific absorbent materials before and after selective adsorption of the combustion gases. Today fully automated systems based on thermal conductivity or infrared spectroscopy detection of the combustion gases, or other spectroscopic methods are us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Structural Elucidation
A chemical structure determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid. Molecular geometry refers to the spatial arrangement of atoms in a molecule and the chemical bonds that hold the atoms together, and can be represented using structural formulae and by molecular models; complete electronic structure descriptions include specifying the occupation of a molecule's molecular orbitals. Structure determination can be applied to a range of targets from very simple molecules (e.g., diatomic oxygen or nitrogen), to very complex ones (e.g., such as protein or DNA). Background Theories of chemical structure were first developed by August Kekulé, Archibald Scott Couper, and Aleksandr Butlerov, among others, from about 1858. These theories were first to state that chemical compounds are not a random cluster of atoms and functional groups, but rather had a definite order de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reimer–Tiemann Reaction
The Reimer–Tiemann reaction is a chemical reaction used for the ortho-formylation of phenols; with the simplest example being the conversion of phenol to salicylaldehyde. The reaction was discovered by and Ferdinand Tiemann. The Reimer in question was Karl Reimer (1845-1883) not the lesser known Carl Ludwig Reimer (1856-1921). Reaction mechanism Chloroform (1) is deprotonated by a strong base (normally hydroxide) to form the chloroform carbanion (2) which will quickly alpha-eliminate to give dichlorocarbene (3); this is the principal reactive species. The hydroxide will also deprotonate the phenol (4) to give a negatively charged phenoxide (5). The negative charge is delocalised into the aromatic ring, making it far more nucleophilic. Nucleophilic attack on the dichlorocarbene gives an intermediate dichloromethyl substituted phenol (7). After basic hydrolysis, the desired product (9) is formed. Selectivity By virtue of its 2 electron-withdrawing chlorine groups, carbene (3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curriculum Vitae
In English, a curriculum vitae (,Definition of "curriculum vitae" by Oxford Dictionary on Lexico.com Latin for "course of life", often shortened to CV) is a short written summary of a person's career, qualifications, and education. This is the most common usage in both and . In North America (but not elsewhere), the term |
