Organophosphorus compounds are chemical compounds containing carbon phosphorus bonds. Organophosphorus chemistry is the corresponding science exploring the properties and reactivity of organophosphorus compounds. Phosphorus shares group 14 in the periodic table with nitrogen and phosphorus compounds and nitrogen compounds have much in common ^{[1] [2]}. A chemical compound is a chemical substance formed from two or more elements, with a fixed ratio determining the composition. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... This article is about the chemical element. ... A chemical bond is the physical phenomenon of chemical substances being held together by attraction of atoms to each other through sharing, as well as exchanging, of electrons -or electrostatic forces. ... The Nitrogen group elements (a. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ...

Phosphorus can adopt oxidation states -3, -1, 1, 3 and 5. In chemical literature very often compounds with +3 or -3 oxidation state are grouped together as having a (III) oxidation state regardless of sign. In a official and more descriptive nomenclature phosphorus compounds are identified by their coordination number δ and their valency λ. In this system a phosphine is a δ³λ³ compound. In chemistry, the oxidation state is a measure of the degree of oxidation of an atom in a chemical compound. ... In chemistry, the coordination number is the sum of the total number of neighbors of a central atom in a chemical compound and the number of lone pairs on it. ... Sigma may refer to: Sigma (letter) (Σ, σ, or Ï‚), of the Greek alphabet In science: Summation operator forming a series in mathematics Σ Standard deviation of a population in statistics σ Divisor function in number theory σ A busy beaver function in computability theory Σ Stefan-Boltzmann constant of radiation in physics σ Sigma factor of RNA... In chemistry, valency is the power of an atom of an element to combine with other atoms measured by the number of electrons which an atom will give, take, or share to form a chemical compound. ... Lambda (upper case Λ, lower case λ) is the 11th letter of the Greek alphabet. ...

Phosphines

The parent compound of the phosphines is phosphine (PH₃). Phosphines have oxidation state -3 (δ³λ³) and are the phosphorus analogues of simple amines. An often used organic phosphine is triphenylphosphine. Like amines, phosphines have a trigonal pyramidal molecular geometry although with larger angles. The C-P-C bond angle is 98.6° for trimethylphosphine increasing to 109.7 when the methyl groups are replaced by tert-butyl groups. R-phrases , , , , S-phrases , , , , , Flash point flammable gas Autoignition temperature 38 °C (see text) Explosive limits 1. ... Ammonia Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... Flash point 180 °C RTECS number SZ3500000 Supplementary data page Structure and properties n, εr, etc. ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... In organic chemistry, butyl is a four-carbon alkyl substituent with chemical formula -C4H9. ...

The barrier to inversion is also much higher than in amines for a process like nitrogen inversion to occur and therefore phosphines with three different substituents can display optical isomerism. In chemistry, a nitrogen compound like ammonia in a trigonal pyramid geometry undergoes rapid nitrogen inversion whereby the molecule turns inside out. ... In organic chemistry, a substituent is an atom or group of atoms subsituted in place of a hydrogen atom on the parent chain of a hydrocarbon. ... Optical isomerism is a form of isomerism (specifically stereoisomerism) where the two different isomers are the same in every way except being non-superposable mirror images of each other. ...

The basicity of phospines is less than that of corresponding amines for instance trietylphosphine has a pKa of 5.4 compared to that of 3.2 of triethylamine. Likewise triphenylphosphine (pKa 11.2) is less basic than triphenylamine (Pka 19). In chemistry and biochemistry, acid dissociation constant, the acidity constant, or the acid-ionization constant () is a specific type of equilibrium constant that indicates the extent of dissociation of hydrogen ions from an acid. ... Triethylamine, also known as N,N-diethylethanamine, TEA or N,N,N-Triethylamine, is a colorless, volatile liquid with a strong, unpleasant and fishy smell reminiscent of ammonia. ...

Amines and phosphines both have a lone pair of electrons but with a difference. Whereas the lone pair in an amine shares its electrons at every opportunity for delocalization for instance in pyridine, the phosphorus atom in a similar configuration will not. For this reason, the phosphorus equivalent of pyrrole called phosphole is not at all aromatic. A lone pair is an electron pair without bonding or sharing with other atoms. ... In chemistry, delocalized electrons are electrons in a molecule that do not belong to a single atom or a covalent bond. ... R-phrases , , , S-phrases , , Flash point 20 °C Supplementary data page Structure and properties n, εr, etc. ... Pyrrole, or pyrrol, is a heterocyclic aromatic organic compound, a five-membered ring with the formula C4H5N. Pyrroles are components of larger aromatic rings, including the porphyrins of heme, the chlorins and bacteriochlorins of chlorophyll, and the corrin ring of vitamin B12. ... In chemistry, an aromatic molecule is one in which electrons are free to cycle around circular arrangements of atoms, which are alternately singly and doubly bonded to one another. ...

The reactivity of phosphines match that of amines with regard to nucleophilicity in the formation of Phosphonium salts with the general structure PR₄⁺X^-. This property is used in the Appel reaction converting alcohols to alkyl halides. In chemistry, a nucleophile (literally nucleus lover) is a reagent which is attracted to centres of positive charge. ... The Appel reaction is a chemical reaction that converts an alcohol into an alkyl chloride using triphenylphosphine and carbon tetrachloride. ... In chemistry, an alcohol is any organic compound in which a hydroxyl group (-OH) is bound to a carbon atom, which in turn is bound to other hydrogen and/or carbon atoms. ... In chemistry, an alkyl halide is an organic molecule of the form R_X, where X is a halide and R contains a carbon atom bonded to other functional groups or hydrogens. ...

A difference in reactivity with amines is the ease of oxidation of phosphines to phosphine oxides. The most fundamental reactions in chemistry are the redox processes. ...

Synthetic produces for phosphines are:

• Nucleophilic displacement of phosphorous halides with organometallic reagents such as Grignard reagents.
• Nucleophilic displacement of metal phosphides, generated by reaction of potassium metal with phosphine as in sodium amide with alkyl halides.
• Nucleophilic addition of phosphine with alkenes in presence of a strong base (often KOH in DMSO), Markovnikov's rules apply ^[3]. Phosphine can be prepared in situ from red phosphorus and potassium hydroxide. Primary (RPH₂) and secondary phospines (RRPH) do not require a base with electron-deficient alkenes such as acrylonitriles.

• Radical addition of phosphines to alkenes with AIBN or organic peroxides to give anti-Markovnikov adducts.
• Nucleophilic addition of phosphine and phosphines to alkynes in presence of base. Secondary phosphines react with electron-deficient alkynes such as phenylcyanoacetylene without base.
• Organic reduction of phosphine oxides for instance with chlorosilane.

The main reaction types of phosphines are: In chemistry, nucleophilic substitution is a class of substitution reaction in which an electron-rich nucleophile attacks a molecule and replaces a group or atom, called the leaving group. ... A Grignard Reagent is an alkyl- or aryl- magnesium halide. ... Sodium amide, also called sodamide, is a flammable powder with chemical formula NaNH2. ... In chemistry, an alkyl halide is an organic molecule of the form R_X, where X is a halide and R contains a carbon atom bonded to other functional groups or hydrogens. ... In organic chemistry, a nucleophilic addition reaction is an addition reaction where in a chemical compound a pi bond is removed by the creation of two new covalent bonds by the addition of a nucleophile. ... An alkene in organic chemistry is an unsaturated hydrocarbon containing at least one carbon to carbon double bond. ... R-phrases , S-phrases , , , Flash point non flammable RTECS number TT2100000 Supplementary data page Structure and properties n, εr, etc. ... Dimethyl Sulfoxide (DMSO, empirically C2H6OS), also known as methyl sulfoxide or sulfinylbismethane, is a chemical compound. ... In chemistry, Markovnikovs rule is an observation based on Zaitsevs rule. ... R-phrases , S-phrases , , , Flash point non flammable RTECS number TT2100000 Supplementary data page Structure and properties n, εr, etc. ... Acrylonitrile (CH2=CH-C≡N), is a pungent smelling, extremely flammable organic liquid. ... In Organic chemistry, a radical addition reaction is an addition reaction in which the first species that adds is a radical. ... Azobisisobutyronitrile, also azobisisobutylonitrile, is a toxic white crystalline compound often used as a foamer in plastics and rubber. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... In organic chemistry, a nucleophilic addition reaction is an addition reaction where in a chemical compound a pi bond is removed by the creation of two new covalent bonds by the addition of a nucleophile. ... Alkynes are hydrocarbons that have at least one triple bond between two carbon atoms. ... Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. ... Chlorosilanes are a group of reactive, chlorine-containing chemical compounds, related to silane and used in many chemical processes. ...

• as nucleophiles for instance with alkyl halides to phosphonium salts.
• as reducing agents:

Phosphines are reducing agents in the Stauding reduction converting azides to amines and in the Mitsunobu reaction converting alcohols into esters. In these processes the phosphine is oxidized to the phosphine oxide. Phosphines have also been found to reduce activated carbonyl groups for instance the reduction of an α-keto ester to an α-hydroxy ester in scheme 2 ^[4]. In the proposed reaction mechanism the first proton is on loan from the methyl group in trimethylphosphine (triphenylphosphine does not react).

When modified with suitable substituents as in certain diazaphospholenes (scheme 3) the polarity of the P-H bond can actually be inverted (see: umpolung) and the resulting phosphine hydride can reduce a carbonyl group as in the example of benzophenone in yet another way ^[5].

• Multidentate phosphines such as BINAP are important ligands in organometallic chemistry.

In chemistry, an alkyl halide is an organic molecule of the form R_X, where X is a halide and R contains a carbon atom bonded to other functional groups or hydrogens. ... A reducing agent is the element or a compound in a redox (reduction-oxidation) reaction (see electrochemistry) that reduces another species. ... The Mitsunobu reaction is an organic reaction that can convert an alcohol into a variety of functional groups, such as esters using triphenylphosphine and diethyl azodicarboxylate (DEAD). ... In chemistry, a reaction mechanism is the step by step sequence of elementary reactions by which overall chemical change occurs. ... Umpolung or polarity inversion in organic chemistry is the chemical modification of a functional group with the aim the reversal of polarity of that group. ... A hydride is a compound of hydrogen with more electropositive elements. ... Benzophenone, also known as diphenylmethanone, phenyl ketone, diphenyl ketone, or benzoylbenzene. ... BINAP is an acronym used for 2,2-bis(diphenylphosphino)-1,1-binaphthyl, an important compound used in chiral synthesis. ... It has been suggested that this article or section be merged with Ligand (biochemistry). ...

Phosphites

Phosphites or phosphite ester have the general structure P(OR)₃ with oxidation state +3. Phosphites are employed in the Perkow reaction. The phosphite ion is a polyatomic ion with phosphorus as its central atom. ... The Perkow reaction is an organic reaction in which a trialkyl phosphite ester reacts with a haloketone to form a vinyl phosphonate and an alkyl halide. ...

Phosphine oxides

Phosphine oxides (designation δ³λ³) have the general structure P=OR₃ with formal oxidation state -1. Phospines form hydrogen bonds and many phosphines are therefore soluble in water. The P=O bond is very polar with a dipole moment of 4.51 D for triphenylphosphine. Snapshot from a simulation of liquid water. ... This article is about the electromagnetic phenomenon. ...

The nature of the phosphorus to oxygen double bond is a matter of debate. Pentavalent phosphorus like nitrogen is not compatible with the octet rule. In older literature the bond is represented as a dative bond just like a amine oxide. The prevailing view is that of a full double bond with back bonding taking place between a filled oxygen electron pair and an empty phosphorus d-orbital (lacking in nitrogen). problem is: the P=O bond does not react as any C=C double bond as addition reactions are absent and involvement of a phosphorus d-orbital in bonding is not supported in silico. Alternative theories favor an ionic bond P⁺-O^- which on its own strength should explain the short bond length. The octet rule is a simple chemical theory that states that atoms tend to combine in such a way that they each have eight electrons in their valence shells, similar to the electronic configuration of a noble gas. ... A coordinate covalent bond (also known as dative covalent bond) is a special type of covalent bond in which the shared electrons come from one of the atoms only. ... An amine oxide, also known as amine-N-oxide and N-oxide, is a chemical compound that contains the functional group R3N+-O− (sometimes written as R3N=O or R3N→O). ... An addition reaction, in chemistry, is in its simplest terms a organic reaction where two or more molecules combine to form a larger one. ... in silico is an expression used to mean performed on computer or via computer simulation. ... Electron configurations of lithium and fluorine. ... Bond length or bond distance in molecular geometry is the distance between two bonded atoms in a molecule. ...

Phospines are easily oxidized to phosphine oxides as examplified by the template directed synthesis of a phospha crown, the phosphorus analogue of an aza crown ^[6] where it is not possible to isolate the phosphine itself ^[7].

Phosphonates

Phosphonates have the general structure P=0(OR)₂R. In the Horner-Wadsworth-Emmons reaction and the Seyferth-Gilbert homologation phosphonates are used as stabilized carbanions in reactions with carbonyl compounds. The Horner-Wadsworth-Emmons reaction is the chemical reaction of stabilized phosphonate carbanions with aldehydes (or ketones) to produce predominantly E-alkenes. ... The Seyferth-Gilbert homologation is a the chemical reaction of an aryl ketone 1 (or aldehyde) with dimethyl (diazomethyl)phosphonate 2 and potassium tert-butoxide to give substituted alkynes 3. ... A carbanion is an anion in which carbon has an unshared pair of electrons and bears a negative charge usually with three substituents for a total of eight valence electrons. ... Carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom. ...

Phosphates

Organophosphates or phosphate esters with the general structure P=O(OR)₃ and oxidation state +5 are of great technological importance as flame retardant agents and plasticizers. An organophosphate (sometimes abbreviated OP) is the general name for any organic compound containing phosphorus. ... Flame retardants are materials that inhibit or resist the spread of fire. ... Plasticizers are additives that soften the materials (usually a plastic or a concrete mix) they are added to. ...

Phosphoranes

Phosphoranes have a -5 oxidation state (δ⁵λ⁵) with parent compound the non-stable phosphoran PH₅ or λ5-Phosphan (lambda5phosphan). Phosphorus ylides are unsaturated phosphoranes used in the Wittig reaction. A ylide is a neutral molecule with positive and negative charges on adjacent atoms. ... The Wittig reaction is a chemical reaction of an aldehyde or ketone with a phosphonium ylide to give an alkene and triphenylphosphine oxide. ...

Phosphorus multiple bonds

Many compounds exist with carbon phosphorus multiple bonds (P=C) as phosphaalkenes (R₂C::PR) and phosphaalkynes (RC:::PR). In the compound Phosphorine one carbon atom in benzene is replaced by phosphorus. The reactivity of phosphaalkenes is often compared to that of alkenes and not to that of imines. The reason is that the HOMO of phosphaalkenes is not the phosphorus lone pair (as in imines) but the double bond. Diphosphenes are compounds containing P=P phosphorous double bonds. Chemical structure of phosphorine Phosphorine is a heavy benzene containing a phosphorus atom instead of a CH moiety, so it is considered to be a heavier element analog of pyridine. ... An alkene in organic chemistry is an unsaturated hydrocarbon containing at least one carbon to carbon double bond. ... An imine is a functional group or chemical compound containing a carbon-nitrogen double bond. ... Look up homo in Wiktionary, the free dictionary. ... A lone pair is an electron pair without bonding or sharing with other atoms. ...

See also

• Compounds of carbon with period 3 elements: organosilicon compounds, organophosphorus compounds, organosulfur compounds,

A period 3 element is one of the chemical elements in the third row (or period) of the periodic table of the elements. ... Organosulfur compounds are organic compounds containing sulfur. ...

External links

• organophosphorus chemistry @ http://users.ox.ac.uk Link

References

1. ↑  Phosphorus. The Carbon Copy Keith B. Dillon, Francois Mathey, John F. Nixon 1997 John Wiley & Sons ISBN 0471973602
2. ↑  A Guide to Organophosphorus Chemistry Louis D. Quin 2000 John Wiley & Sons ISBN 0-471-31824-8
3. ↑  Nucleophilic and free-radical additions of phosphines and phosphine chalcogenides to alkenes and alkynes Svetlana N. Arbuzova, Nina K. Gusarova, Boris A. Trofimov Arkivoc AL-1672FP pp 29-37 2006 Article
4. ↑  Reduction of activated carbonyl groups by alkyl phosphines: formation of -hydroxy esters and ketones Wen Zhang and Min Shi Chemical Communications, 2006, 1218 - 1220 Abstract
5. ↑  P-Hydrogen-Substituted 1,3,2-Diazaphospholenes: Molecular Hydrides Sebastian Burck, Dietrich Gudat, Martin Nieger, and Wolf-Walther Du Mont J. Am. Chem. Soc.; 2006; 128(12) pp 3946 - 3955; Abstract
6. ↑  Template Synthesis of 1,4,7-Triphosphacyclononanes Peter G. Edwards, Robert Haigh, Dongmei Li, and Paul D. Newman J. Am. Chem. Soc.; 2006; 128(11) pp 3818 - 3830; Abstract
7. ↑  In step 1 diphosphinoethane coordinates to a ferrocene containing additional carbon monoxide ligands and a acetonitrile ligand. The next step is a hydrophosphination with trivinylphosphine followed by alkylation with ethyl bromide and hydrogenation with hydrogen over palladium on carbon. In the final step the iron template is removed by bromine but oxidation of the phosphine groups is unavoidable.