Phosphinimide Ligands on:
[Wikipedia]
[Google]
[Amazon]
In chemistry a phosphine imide (sometimes abbreviated to phosphinimide) also known as a iminophosphorane is a
functional group
In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...
with the formula R3P=NR. While structurally related to phosphine oxide
Phosphine oxide is the inorganic compound with the formula H3PO. Although stable as a dilute gas, liquid or solid samples are unstable. Unlike many other compounds of the type POxHy, H3PO is rarely discussed and is not even mentioned in major so ...
its chemistry has more in common with phosphonium ylide
An ylide () or ylid () is a neutral dipolar molecule containing a formally negatively charged atom (usually a carbanion) directly attached to a heteroatom with a formal positive charge (usually nitrogen, phosphorus or sulfur), and in which both ...
s.
Anions of this group, with the structure R3P=N−, are called phosphinoimidates and are used as ligands to form phosphinimide complexes which are highly active catalysts in some olefin polymerization reactions.
Synthesis
Phosphine imides can be isolated as intermediates in theStaudinger reaction
The Staudinger reaction is a chemical reaction of an organic azide with a phosphine or phosphite produces an iminophosphorane. The reaction was discovered by and named after Hermann Staudinger. The reaction follows this stoichiometry:
:R3P + R ...
and have also been prepared by the action of hydroxylamine-O-sulfonic acid
Hydroxylamine-''O''-sulfonic acid (HOSA) or aminosulfuric acid is the inorganic compound with molecular formula H3NO4S that is formed by the sulfonation of hydroxylamine with oleum. It is a white, water-soluble and hygroscopic, solid, commonly r ...
on phosphine
Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula , classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting ...
s, proceeding via a p-aminophosphonium salt.
Reactions and applications
The functional group will readily hydrolyse to give aphosphine oxide
Phosphine oxide is the inorganic compound with the formula H3PO. Although stable as a dilute gas, liquid or solid samples are unstable. Unlike many other compounds of the type POxHy, H3PO is rarely discussed and is not even mentioned in major so ...
and an amine
In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...
:R3P=NR' + H2O → R3P=O + R'NH2
Phosphinimide ligands of the general formula NPR3− form transition metal phosphinimide complexeses. Some of these complexes are potential catalysts for the synthesis of polyethylene
Polyethylene or polythene (abbreviated PE; IUPAC name polyethene or poly(methylene)) is the most commonly produced plastic. It is a polymer, primarily used for packaging (plastic bags, plastic films, geomembranes and containers including bott ...
.
See also
*Aminophosphine In organophosphorus chemistry, aminophosphines are compounds with the formula R3−nP(NR2)n where R is a hydrogen or organic substituent, and n = 0, 1, or 2. At one extreme, the parents H2PNH2 and are lightly studied and fragile. At the other extre ...
* Phosphazene
Phosphazenes refer to various classes of organophosphorus compounds featuring phosphorus(V) with a double bond between P and N. One class of phosphazenes have the formula . These phosphazenes are also known as iminophosphoranes and phosphine imides ...
References
{{Functional groups Functional groups