The present invention provides a method for the preparation of polymeric
organic iridium complexes useful in electronic devices such as OLEDs. The
method provides polymeric organic iridium compositions comprising at
least one cyclometallated ligand and at least one ketopyrrole ligand. The
polymeric organic iridium compositions provided are referred to as Type
(2) organic iridium compositions and are constituted such that at least
one ligand of the polymeric organic iridium compound has a number average
molecular weight of 2,000 grams per mole or greater (as measured by gel
permeation chromatography). Type (2) organic iridium compositions are
referred to herein as comprising "polymeric organic iridium complexes".
In one embodiment, the method comprises providing a non-polymeric organic
iridium complex comprising one or more reactive functional groups and
carrying out a polymerization step to provide the polymeric organic
iridium complex comprising at least one cyclometallated ligand and at
least one ketopyrrole ligand.