phosphine imide
{{Short description|Functional group}}
File:Ph3P=NPh.png is a simple commercially available phosphine imide where all R-groups are phenyls]]
In chemistry a phosphine imide (sometimes abbreviated to phosphinimide) also known as a iminophosphorane is a functional group with the formula R3P=NR. While structurally related to phosphine oxide its chemistry has more in common with phosphonium ylides.
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.{{cite journal |last1=Dehnicke |first1=Kurt |last2=Krieger |first2=Matthias |last3=Massa |first3=Werner |title=Phosphoraneiminato complexes of transition metals |journal=Coordination Chemistry Reviews |date=February 1999 |volume=182 |issue=1 |pages=19–65 |doi=10.1016/S0010-8545(98)00191-X}}
Synthesis
Phosphine imides can be isolated as intermediates in the Staudinger reaction and have also been prepared by the action of hydroxylamine-O-sulfonic acid on phosphines, proceeding via a p-aminophosphonium salt.{{cite journal |last1=Appel |first1=Rolf |last2=Büchner |first2=Werner |last3=Guth |first3=Egbert |title=Zur Kenntnis des Imins, I. Über Phosphinimine und Sulfimine |journal=Justus Liebigs Annalen der Chemie |date=26 November 1958 |volume=618 |issue=1 |pages=53–58 |doi=10.1002/jlac.19586180107}}
Reactions and applications
The functional group will readily hydrolyse to give a phosphine oxide and an amine
: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.