Patent ID: 7083862

Claim:
A light emitting device comprising at least one compound of the formula: where x is 3, 2 or 1, y is 0 or 1, n 1 and n 2 , which may be the same or different, are 0 or 1 to 3, X represents a divalent mono- or poly-aromatic moiety or a divalent mono- or poly-heteroaromatic moiety or combinations thereof, the or each Y, which may be the same or different if x is 1, represents hydrogen or an optionally substituted hydrocarbon group, Z represents an at least partly conjugated dendritic molecular structure comprising aromatic or heteroaromatic groups or combinations thereof and, optionally, additionally comprising alkenylene groups, the aromatic or heteroaromatic groups or combinations thereof being connected to each other either via a ring carbon atom of an aromatic or heteroaromatic group to a ring carbon atom of another aromatic or heteroaromatic group or, if an alkenylene group is present via, a ring carbon atom of an aromatic or heteroaromatic group to a carbon atom of an alkylene group, said dendritic molecular structure being connected to the remainder of the molecule via a ring carbon atom of an aromatic or heteroaromatic group to which more than one at least partly conjugated dendritic chain is attached, one or more of the aromatic or heteroaromatic rings of the dendrimers optionally being substituted, and where Z or the remainder of the molecule or both, excluding any groups Y, is luminescent, and with the proviso that when n 2 is 0, x must be 3.