Electroluminescent Materials and Devices

1 .- 24 . (canceled)

25 . An electroluminescent compound of formula

wherein:

Ar is tertiary alkyl or is a substituted or unsubstituted aromatic group; and

R 1 and R 2 may be the same or different and are selected from the group consisting of hydrogen, hydrocarbyl groups, substituted and unsubstituted aliphatic groups, aromatic groups, heterocyclic groups fluorocarbon groups and polycyclic ring structures, or R 1 and R 2 may together form substituted or unsubstituted fused aromatic, heterocyclic and polycyclic ring structures and can be copolymerizable with styrene or with another monomer.

26 . The compound of claim 25 , wherein Ar is selected from

27 . Any of the following compounds:

9,10-bis-(4-methylbenzyl)-anthracene;

9,10-bis-(2,4-dimethylbenzyl)-anthracene;

9,10-bis-(2,5-dimethylbenzyl)-anthracene;

9,10-bis-(2,3,5,6-tetramethylbenzyl)-anthracene;

9,10-bis-(4-methoxulbenzyl)-anthracene;

9,10-bis-(9H-fluoren-9-yl)-anthracene;

2.6-di-t-butylanthracene;

2.6-di-t-adamantyl-lanthracene;

2.6-di-t-butyl-9,10-bis-(2,5-dimethylbenzyl)-anthracene;

2.6-di-t-butyl-9,10-bis-naphthalen-1-yl-anthracene.

28 . An electroluminescent composition comprising

(i) an electroluminescent compound of formula

wherein:

Ar is tertiary alkyl or is a substituted or unsubstituted aromatic group; and

R 1 and R 2 may be the same or different and are selected from the group consisting of hydrogen, hydrocarbyl groups, substituted and unsubstituted aliphatic groups, aromatic groups, heterocyclic groups fluorocarbon groups and polycyclic ring structures, or R 1 and R 2 may together form substituted or unsubstituted fused aromatic, heterocyclic and polycyclic ring structures and can be copolymerizable with styrene or with another monomeras defined in claim 1 and

(ii) a host material.

29 . The composition of claim 28 , wherein the host forms a common phase with the electroluminescent compound.

30 . The composition of claim 28 , wherein the host is of formula:

wherein R 1 and R 2 may be hydrogen or substituted or unsubstituted hydrocarbyl.

31 . The composition of claim 28 , wherein the host is of formula:

32 . An electroluminescent device which comprises

(i) a first electrode,

(ii) a layer comprising an electroluminescent compound of formula

wherein:

Ar is tertiary alkyl or is a substituted or unsubstituted aromatic group; and

R 1 and R 2 may be the same or different and are selected from the group consisting of hydrogen, hydrocarbyl groups, substituted and unsubstituted aliphatic groups, aromatic groups, heterocyclic groups fluorocarbon groups and polycyclic ring structures, or R 1 and R 2 may together form substituted or unsubstituted fused aromatic, heterocyclic and polycyclic ring structures and can be copolymerizable with styrene or with another monomer and

(iii) a second electrode.

33 . The device of claim 32 , wherein there is a layer of ZnTpTp or of the following compound between the first electrode and the electron injection layer:

34 . The device of claim 32 , wherein there is a layer of a hole transmitting material between the first electrode and the electroluminescent layer.

35 . The device of claim 34 , wherein the hole transmitting material is an aromatic amine compound.

36 . The device of claim 34 , wherein the hole transmitting layer is of a material selected from:

(a) α-NBP;

(b) a film of a polymer selected from poly(vinylcarbazole), N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine (TPD), polyaniline, substituted polyanilines, polythiophenes, substituted polythiophenes, polysilanes and substituted polysilanes;

(c) a copolymer of aniline, a copolymer of aniline with o-anisidine, m-sulphanilic acid or o-aminophenol, or o-toluidine with o-aminophenol, o-ethylaniline, o-phenylene diamine or with an amino anthracene;

(d) a conjugated polymer selected from poly(p-phenylenevinylene)-PPV and copolymers including PPV, poly(2,5 dialkoxyphenylene vinylene), poly(2-methoxy-5-(2-methoxypentyloxy-1,4-phenylene vinylene), poly(2-methoxypentyloxy)-1,4-phenylenevinylene), poly(2-methoxy-5-(2-dodecyloxy-1,4-phenylenevinylene) and other poly(2,5 dialkoxyphenylenevinylenes) with at least one of the alkoxy groups being a long chain solubilising alkoxy group, poly fluorenes and oligofluorenes, polyphenylenes and oligophenylenes, polyanthracenes and oligo anthracenes, ploythiophenes and oligothiophenes.

37 . The device of claim 32 , wherein there is a layer of an electron transmitting material between the cathode and the electroluminescent compound layer.

38 . The device of claim 37 , wherein the electron transmitting material is a metal quinolate or a metal thioxinate.

39 . The device of claim 38 , wherein the metal quinolate is an aluminium quinolate, zirconium quinolate, hafnium quinolate or lithium quinolate and the metal thioxinate is zinc thioxinate, cadmium thioxinate, gallium thioxinate or indium thioxinate.

40 . The device of claim 32 , wherein the first electrode is a transparent electricity conducting glass electrode.

41 . The device of claim 32 , wherein the second electrode is comprised of a metal other than an alkali metal having a work function of less than 4 eV.

42 . The device of claim 32 , wherein the second electrode is selected from aluminium, calcium, lithium, magnesium and alloys thereof and silver/magnesium alloys.