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29-496: A functional group is a group of atoms in a molecule with distinctive chemical properties , regardless of the other atoms in the molecule. The atoms in a functional group are linked to each other and to the rest of the molecule by covalent bonds . For repeating units of polymers , functional groups attach to their nonpolar core of carbon atoms and thus add chemical character to carbon chains. Functional groups can also be charged , e.g. in carboxylate salts ( −COO ), which turns

58-522: A Lewis acidic catalyst is used, such as ferric chloride . Many detailed procedures are available. Because fluorine is so reactive , other methods, such as the Balz–Schiemann reaction , are used to prepare fluorinated aromatic compounds. In the Hunsdiecker reaction , carboxylic acids are converted to organic halide , whose carbon chain is shortened by one carbon atom with respect to

87-431: A large number of branched or ring alkanes that have specific names, e.g., tert-butyl , bornyl , cyclohexyl , etc. There are several functional groups that contain an alkene such as vinyl group , allyl group , or acrylic group . Hydrocarbons may form charged structures: positively charged carbocations or negative carbanions . Carbocations are often named -um . Examples are tropylium and triphenylmethyl cations and

116-412: Is 2, 3, or 4), carbyne for methylidyne, and trityl for triphenylmethyl. Chemical property A chemical property is any of a material's properties that becomes evident during, or after, a chemical reaction ; that is, any attribute that can be established only by changing a substance's chemical identity . Simply speaking, chemical properties cannot be determined just by viewing or touching

145-555: Is preferred over functional class nomenclature (marked as suffix in table) for sulfides, disulfides, sulfoxides and sulfones. Compounds that contain phosphorus exhibit unique chemistry due to the ability of phosphorus to form more bonds than nitrogen, its lighter analogue on the periodic table. Compounds containing boron exhibit unique chemistry due to their having partially filled octets and therefore acting as Lewis acids . methyllithium methylmagnesium chloride trimethylaluminium trimethylsilyl triflate Fluorine

174-412: Is the least reactive of them all. The facility of dehydrohalogenation follows the reverse trend: iodine is most easily removed from organic compounds, and organofluorine compounds are highly stable. Halogenation of saturated hydrocarbons is a substitution reaction . The reaction typically involves free radical pathways. The regiochemistry of the halogenation of alkanes is largely determined by

203-587: Is the route to the anesthetic halothane from trichloroethylene : Iodination and bromination can be effected by the addition of iodine and bromine to alkenes. The reaction, which conveniently proceeds with the discharge of the color of I 2 and Br 2 , is the basis of the analytical method . The iodine number and bromine number are measures of the degree of unsaturation for fats and other organic compounds. Aromatic compounds are subject to electrophilic halogenation : This kind of reaction typically works well for chlorine and bromine . Often

232-420: Is too electronegative to be bonded to magnesium; it becomes an ionic salt instead. These names are used to refer to the moieties themselves or to radical species, and also to form the names of halides and substituents in larger molecules. When the parent hydrocarbon is unsaturated, the suffix ("-yl", "-ylidene", or "-ylidyne") replaces "-ane" (e.g. "ethane" becomes "ethyl"); otherwise, the suffix replaces only

261-402: Is used commercially for the production of perfluorinated compounds . It generates small amounts of elemental fluorine in situ from hydrogen fluoride . The method avoids the hazards of handling fluorine gas. Many commercially important organic compounds are fluorinated using this technology. Unsaturated compounds , especially alkenes and alkynes , add halogens: In oxychlorination ,

290-402: The cyclopentadienyl anion. Haloalkanes are a class of molecule that is defined by a carbon– halogen bond. This bond can be relatively weak (in the case of an iodoalkane) or quite stable (as in the case of a fluoroalkane). In general, with the exception of fluorinated compounds, haloalkanes readily undergo nucleophilic substitution reactions or elimination reactions . The substitution on

319-400: The hydroxyl functional group ( −OH ) and hydroxyls interact strongly with each other. Plus, when functional groups are more electronegative than atoms they attach to, the functional groups will become polar, and the otherwise nonpolar molecules containing these functional groups become polar and so become soluble in some aqueous environment. Combining the names of functional groups with

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348-454: The carbon chain of the particular carboxylic acid. The carboxylic acid is first converted to its silver salt, which is then oxidized with halogen : Many organometallic compounds react with halogens to give the organic halide: All elements aside from argon , neon , and helium form fluorides by direct reaction with fluorine . Chlorine is slightly more selective, but still reacts with most metals and heavier nonmetals . Following

377-557: The carbon, the acidity of an adjacent proton, the solvent conditions, etc. all can influence the outcome of the reactivity. Compounds that contain C-O bonds each possess differing reactivity based upon the location and hybridization of the C-O bond, owing to the electron-withdrawing effect of sp-hybridized oxygen (carbonyl groups) and the donating effects of sp-hybridized oxygen (alcohol groups). [REDACTED] Compounds that contain nitrogen in this category may contain C-O bonds, such as in

406-428: The case of amides . (acetimidamide) alkyl nitrate alkyl nitrite [REDACTED] [REDACTED] [REDACTED] 4-pyridyl (pyridin-4-yl) 3-pyridyl (pyridin-3-yl) 2-pyridyl (pyridin-2-yl) Compounds that contain sulfur exhibit unique chemistry due to sulfur's ability to form more bonds than oxygen, its lighter analogue on the periodic table. Substitutive nomenclature (marked as prefix in table)

435-408: The chemical properties of a substance to guide its applications. This chemistry -related article is a stub . You can help Misplaced Pages by expanding it . Fluorination In chemistry , halogenation is a chemical reaction which introduces one or more halogens into a chemical compound . Halide -containing compounds are pervasive, making this type of transformation important, e.g. in

464-426: The combination of hydrogen chloride and oxygen serves as the equivalent of chlorine , as illustrated by this route to 1,2-dichloroethane : The addition of halogens to alkenes proceeds via intermediate halonium ions . In special cases, such intermediates have been isolated. Bromination is more selective than chlorination because the reaction is less exothermic . Illustrative of the bromination of an alkene

493-540: The final "-e" (e.g. " ethyne " becomes " ethynyl "). When used to refer to moieties, multiple single bonds differ from a single multiple bond. For example, a methylene bridge (methanediyl) has two single bonds, whereas a methylidene group (methylidene) has one double bond. Suffixes can be combined, as in methylidyne (triple bond) vs. methylylidene (single bond and double bond) vs. methanetriyl (three double bonds). There are some retained names, such as methylene for methanediyl, 1,x- phenylene for phenyl-1,x-diyl (where x

522-674: The free radical iodination. Because of its extreme reactivity, fluorine ( F 2 ) represents a special category with respect to halogenation. Most organic compounds, saturated or otherwise, burn upon contact with F 2 , ultimately yielding carbon tetrafluoride . By contrast, the heavier halogens are far less reactive toward saturated hydrocarbons. Highly specialised conditions and apparatus are required for fluorinations with elemental fluorine . Commonly, fluorination reagents are employed instead of F 2 . Such reagents include cobalt trifluoride , chlorine trifluoride , and iodine pentafluoride . The method electrochemical fluorination

551-418: The gamma-amine in gamma-aminobutyric acid is on the third carbon of the carbon chain attached to the carboxylic acid group. IUPAC conventions call for numeric labeling of the position, e.g. 4-aminobutanoic acid. In traditional names various qualifiers are used to label isomers , for example, isopropanol (IUPAC name: propan-2-ol) is an isomer of n-propanol (propan-1-ol). The term moiety has some overlap with

580-460: The halogenation of organic compounds, including free radical halogenation , ketone halogenation , electrophilic halogenation , and halogen addition reaction . The nature of the substrate determines the pathway. The facility of halogenation is influenced by the halogen. Fluorine and chlorine are more electrophilic and are more aggressive halogenating agents. Bromine is a weaker halogenating agent than both fluorine and chlorine, while iodine

609-449: The molecule into a polyatomic ion or a complex ion . Functional groups binding to a central atom in a coordination complex are called ligands . Complexation and solvation are also caused by specific interactions of functional groups. In the common rule of thumb "like dissolves like", it is the shared or mutually well-interacting functional groups which give rise to solubility . For example, sugar dissolves in water because both share

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638-456: The names of the parent alkanes generates what is termed a systematic nomenclature for naming organic compounds . In traditional nomenclature, the first carbon atom after the carbon that attaches to the functional group is called the alpha carbon ; the second, beta carbon, the third, gamma carbon, etc. If there is another functional group at a carbon, it may be named with the Greek letter, e.g.,

667-474: The production of polymers , drugs . This kind of conversion is in fact so common that a comprehensive overview is challenging. This article mainly deals with halogenation using elemental halogens ( F 2 , Cl 2 , Br 2 , I 2 ). Halides are also commonly introduced using salts of the halides and halogen acids. Many specialized reagents exist for and introducing halogens into diverse substrates , e.g. thionyl chloride . Several pathways exist for

696-685: The relative weakness of the C–H bonds . This trend is reflected by the faster reaction at tertiary and secondary positions. Free radical chlorination is used for the industrial production of some solvents : Naturally-occurring organobromine compounds are usually produced by free radical pathway catalyzed by the enzyme bromoperoxidase . The reaction requires bromide in combination with oxygen as an oxidant . The oceans are estimated to release 1–2 million tons of bromoform and 56,000 tons of bromomethane annually. The iodoform reaction , which involves degradation of methyl ketones , proceeds by

725-635: The substance's structure. However, for many properties within the scope of physical chemistry , and other disciplines at the boundary between chemistry and physics , the distinction may be a matter of researcher's perspective . Material properties , both physical and chemical, can be viewed as supervenient ; i.e., secondary to the underlying reality. Several layers of superveniency are possible. Chemical properties can be used for building chemical classifications . They can also be useful to identify an unknown substance or to separate or purify it from other substances. Materials science will normally consider

754-420: The substance; the substance's internal structure must be affected greatly for its chemical properties to be investigated. When a substance goes under a chemical reaction, the properties will change drastically, resulting in chemical change . However, a catalytic property would also be a chemical property. Chemical properties can be contrasted with physical properties , which can be discerned without changing

783-407: The symbols R and R' usually denote an attached hydrogen, or a hydrocarbon side chain of any length, but may sometimes refer to any group of atoms. Hydrocarbons are a class of molecule that is defined by functional groups called hydrocarbyls that contain only carbon and hydrogen, but vary in the number and order of double bonds. Each one differs in type (and scope) of reactivity. There are also

812-405: The term "functional group". However, a moiety is an entire "half" of a molecule, which can be not only a single functional group, but also a larger unit consisting of multiple functional groups. For example, an "aryl moiety" may be any group containing an aromatic ring , regardless of how many functional groups the said aryl has. The following is a list of common functional groups. In the formulas,

841-405: The usual trend, bromine is less reactive and iodine least of all. Of the many reactions possible, illustrative is the formation of gold(III) chloride by the chlorination of gold . The chlorination of metals is usually not very important industrially since the chlorides are more easily made from the oxides and hydrogen chloride . Where chlorination of inorganic compounds is practiced on

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