Aromatic monomer- and conjugated polymer-metal complexes

Abstract

A halogenated aromatic monomer-metal complex useful for preparing a polymer for electronic devices such as a light-emitting diode (LED) device is described. The aromatic monomer-metal complex is designed to include a linking group that disrupts conjugation, thereby advantageously reducing or preventing electron delocalization between the aromatic monomer fragment and the metal complex fragment. Disruption of conjugation is often desirable to preserve the phosphorescent emission properties of the metal complex in a polymer formed from the aromatic monomer-metal complex. The resultant conjugated electroluminescent polymer has precisely controlled metal complexation and electronic properties that are substantially or completely independent of those of the polymer backbone.

1 . A halogenated aromatic monomer-metal complex compound comprising a halogenated aromatic monomer fragment and a metal complex fragment and represented by the following formula (I): 
       
         
           
           
               
               
           
         
         where L is a bidentate ligand; M is Ir, Rh, or Os; Ar′ and Ar″ are aromatic moieties which may be the same or different with the proviso that at least one of Ar′ and Ar″ is heteroaromatic; and wherein R a  and R b  are each independently a monovalent substitutent or H, with the proviso that at least one of R a  and R b  contains a halogenated aromatic monomer fragment and a linking group that disrupts conjugation between the halogenated aromatic monomer fragment and the metal complex fragment; 
         wherein the halogenated aromatic monomer-metal complex compound is not a compound of formula (I) in which Ar′ represents a benzene moiety, Ar″ represents a pyridine moiety, and R a  represents a phenoxy group which may be substituted by halogen. 
       
     
     
         2 . The compound of  claim 1  wherein Ar′ and Ar″ are each independently selected from the group consisting of benzene, pyridine, thiophene, and fluorene moieties; L is selected from the group consisting of diamines, imines, diimines, heterocyclics containing two nitrogen atoms, diphosphines, β-diketonates, 3-ketonates, salicyliminates, dialcoholates, and dithiolates; and R a  is -G-Ar—X, where G is selected from the group consisting of O, methylene, or oxymethylene, Ar is a benzene, napthalene, or anthracene moiety, and X is a halogen, provided that the compound is not a compound in which Ar′ represents a benzene moiety, Ar″ represents a pyridine moiety, G is O, Ar is benzene, and X is a halogen. 
     
     
         3 . The compound of  claim 2  wherein Ar′ is a benzene moiety and Ar″ is a pyridine moiety; L is selected from the group consisting of β-diketonates, pyridine-2-carboxylates, salicyliminates, derivatives of 8-hydroquinoline, derivatives of quinoline-2-carboxylic acid; and Ar is a benzene moiety; and X is Br. 
     
     
         4 . The compound of  claim 3  wherein L is a β-diketonate.