Light-emitting dendrimers

A compound according to any one of the preceding claims wherein the first aryl moiety of DENDRITE is a 1,3,5-bonded benzene ring.

A compound according to any one of the preceding claims wherein n is 2 and the DENDRITE units are attached in the para position to an aromatic CORE.

A compound according to any one of the preceding claims wherein CORE comprises at least two aromatic rings which are not fused to one another.

A compound according to any one of the preceding claims wherein CORE does not possess a halogen atom attached to an aromatic ring.

A compound according to any one of the preceding claims wherein CORE comprises a distyryl anthracene, porphyrin or distyrylbenzene moiety.

A compound according to any one of the preceding claims, wherein n is two to six.

A compound according to any one of the preceding claims, wherein the or each DENDRITE is at least partly conjugated with CORE.

A compound according to any one of the preceding claims, wherein the aryl moieties in DENDRITE are benzene rings, preferably coupled at ring positions 1, 3 and 5, or are pyridyl, triazinyl or thiophenyl rings.

A compound according to any one of the preceding claims, wherein the DENDRITE structures consist of the alkenyl and (hetero)aryl units coupled together by conjugated linkages in 1st, 2nd, or 3rd (or higher) generation structures of general formula

• 4
• in which x is 1, 2, or 3 and E is a surface group which may be the same or different if more than one.

A compound according to any one of the preceding claims, incorporating one or more electron-withdrawing groups which increase its electron-transporting properties.

A process for preparing a compound of the formula:

• CORE—[DENDRITE]n
• in which CORE represents an atom or group, n represents an integer of at least 1 and DENDRITE, which may be the same or different if n is greater than 1, represents an inherently at least partly conjugated dendritic molecular structure comprising aryl and/or heteroaryl groups and alkenyl groups connected to each other via a carbon atom of an alkenyl group to a ring carbon atom of an aryl or heteroaryl group, CORE terminating in the first single bond which is connected to a ring carbon atom of an (hetero)aryl group to which more than one at least partly conjugated dendritic chain is attached, said ring carbon atom forming part of DENDRITE, the CORE and/or DENDRITE being luminescent, which comprises reacting a 3,5-di(halo) benzaldehyde with a 3,5-di(surface group) styrene, optionally (i) converting the aldehyde group of the benzaldehyde which results from the preceding reaction into a vinyl group and (ii) reacting the vinyl compound with 3,5-di(halo)-benzaldehyde, said combination of steps (i) and (ii) being carried out one or more times, and finally reacting the benzaldehyde which results from the preceding reaction with a moiety which comprises at least the central part of CORE.

A light emitting device incorporating as, or in, its light-emitting element a compound having the formula:

• CORE—[DENDRITE]n
• in which CORE represents an atom or group, n represents an integer of at least 1 and DENDRITE, which may be the same or different if n is greater than 1, represents an inherently at least partly conjugated dendritic molecular structure comprising aryl and/or heteroaryl groups and alkenyl groups connected to each other via a carbon atom of an alkenyl group to a ring carbon atom of an aryl or heteroaryl group, CORE terminating in the first single bond which is connected to a ring carbon atom of an (hetero)aryl group to which more than one at least partly conjugated dendritic chain is attached, said ring carbon atom forming part of DENDRITE, the CORE and/or DENDRITE being luminescent.