The present invention relates to a method comprising the step of a polyfluorene comprising structural groups of the following formulas I 1 or more is reacted with iridium (III) compound of the following formula II.
[Formula 1]

## STR2 ##

In the formula, R ¹ and R ² are independently alkyl, substituted alkyl, aryl, substituted aryl, or combinations thereof, R ⁵ is H or CHO, R ³ and R ⁴ are independently hydrogen, alkyl, substituted alkyl , aryl, substituted aryl, or combinations thereof, R ¹¹ and R ¹² form a monocyclic or bicyclic heteroaromatic ring substituted or unsubstituted together halo R ¹³ are each independently nitro , hydroxy, amino, alkyl, aryl, arylalkyl, alkoxy, substituted alkoxy, substituted alkyl, substituted aryl or substituted arylalkyl, Ar is aryl, heteroaryl, substituted aryl, substituted heteroaryl or a combination thereof, X- is selected direct bond, alkyl, substituted alkyl, and combinations thereof, Y is CHO or NH _2, although Z is CHO or NH _2, not the same as Y-, p-is 0, 1 or 2 . The present invention also relates to the use of such a polyfluorene at polyfluorene and optoelectronic devices is the product of such reaction.
.FIELD 1