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In chemistry
Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...
, phosphine-boranes are organophosphorus compound
Organophosphorus compounds are organic compounds containing phosphorus. They are used primarily in pest control as an alternative to chlorinated hydrocarbons that persist in the environment. Some organophosphorus compounds are highly effective in ...
s with the formula R3−nHnPBH3. They are Lewis acid-Lewis base adducts derived from organophosphine Organophosphines are organophosphorus compounds with the formula PR''n''H3−''n'', where R is an organic substituent. These compounds can be classified according to the value of ''n'': primary phosphines (''n'' = 1), secondary phosphines ...
s (PR3−nHn) and borane
Trihydridoboron, also known as borane or borine, is an unstable and highly reactive molecule with the chemical formula . The preparation of borane carbonyl, BH3(CO), played an important role in exploring the chemistry of boranes, as it indicated ...
(BH3). They are generally colorless or white solids. Since these adducts are air-stable, they represent a protected
Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...
form of the parent organophosphine.
Formation and decomplexation
Typically phosphine-boranes are produced by treating the parent phosphine with a source of borane: :PR3−nHn + BH3 → R3−nHnPBH3 Because borane solutions are expensive or dangerous, the borane is often generated in situ, e.g., by oxidation of borohydride with iodine.{{cite journal , doi=10.1002/9780470132463.ch29, title=Methyldiphenylphosphine-Borane and Dimethylphenylphosphine-Borane, journal =Inorganic Syntheses, year=2007, last1=Mathur, first1=M. A., last2=Myers, first2=W. H., last3=Sisler, first3=H. H., last4=Ryschkewitsch, first4=G. E., pages=128–133, volume=15 Deprotection to liberate the phosphine is often achieved by treatment with atertiary amine
In chemistry, amines (, ) are compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia (), wherein one or more hydrogen atoms have been replaced by a substituent such a ...
:
:R3−nHnPBH3 + R'3N → R'3NBH3 + R3−nHnP
See also
*Frustrated Lewis pair
A frustrated Lewis pair (FLP) is a compound or mixture containing a Lewis acid and a Lewis base that, because of steric hindrance, cannot combine to form a classical adduct. Many kinds of FLPs have been devised, and many simple substrates exhibi ...
, where the borane is often tris(pentafluorophenyl)borane
Tris(pentafluorophenyl)borane, sometimes referred to as "BCF", is the chemical compound . It is a white, volatile solid. The molecule consists of three pentafluorophenyl groups attached in a "paddle-wheel" manner to a central boron atom; the c ...
* Ammonia borane
Ammonia borane (also systematically named amminetrihydridoboron), also called borazane, is the chemical compound with the formula H3NBH3. The colourless or white solid is the simplest molecular boron-nitrogen-hydride compound. It has attracted att ...
, related to phosphine-borane but with ammonia or amines in place of organophosphines
References