Organic luminescent materials containing cycloalkyl ancillary ligands is disclosed, which can be used as emitters in the emissive layer of an organic electroluminescent device. The organic luminescent materials is metal complexes which comprise a new series of cycloalkyl containing acetylacetone type ancillary ligands. These novel ligands can effectively improve the lifetime of the device, change the sublimation characteristics and improve device performance. Also disclosed are an electroluminescent device and a formulation.

A light-emitting element having low driving voltage and high emission efficiency is provided. In the light-emitting element, a combination of a guest material and a host material forms an exciplex. The guest material is capable of converting triplet excitation energy into light emission. Light emission from the light-emitting layer includes light emission from the guest material and light emission from the exciplex. The percentage of the light emission from the exciplex to the light emission from the light-emitting layer is greater than 0 percent and less than or equal to 60 percent. The energy after subtracting the energy of light emission from the exciplex from the energy of light emission from the guest material is greater than 0 eV and less than or equal to 0.23 eV.

An organometallic compound represented by Formula 1:

##STR00001## wherein, in Formula 1, M, X.sub.11, X.sub.12, X.sub.13, X.sub.14, A.sub.11, R.sub.11, R.sub.14, b11, n, L.sub.11, and m are described in the specification.

An organometallic compound represented by Formula 1:

M(L.sub.1).sub.n1(L.sub.2).sub.n2Formula 1 wherein groups M, L.sub.1, L.sub.2, n1, and n2 are the same as they are defined in the specification.

Provided is an organic light-emitting device including a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, the organic layer including a low work function metal compound.

A compound comprising a first ligand L.sub.A having the formula ##STR00001##
Formula I, is disclosed. In Formula I, ring A is a five- or six-membered carbocyclic or heterocyclic ring; Y.sup.1 is selected from carbon and nitrogen; each of X.sup.1 to X.sup.4 is C or N; at least two adjacent R.sup.2s of ring B form a fused structure having the following formula: ##STR00002##
ring C is fused to ring B and the wavy lines are bonds attached to ring B; ring D and ring E are either a 5-membered aromatic ring or a 6-membered aromatic ring; each R.sup.1, R.sup.2, R.sup.3, R.sup.A, R.sup.B, R.sup.C, and R.sup.D is independently selected from a variety of substituents; ligand L.sub.A is coordinated to a metal M and, optionally, linked with other ligands; and M is optionally coordinated to other ligands. Organic light emitting devices and consumer products containing the compounds are also disclosed.

The present invention relates to a compound of formula (I), wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each independently hydrogen or R.sup.a, with proviso that a pair of two substituents selected from R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, and R.sup.3 and R.sup.4 is linked to one another and forms a group of formula (II); a material for an organic electroluminescence device comprising at least one compound of formula (I); an organic electroluminescence device which comprises an organic thin film layer be-tween an anode and a cathode, wherein the organic thin film layer comprises one or more layers and comprises a light emitting layer, and at least one layer of the organic thin film layer comprises at least one compound of formula (I); and an electronic equipment comprising the inventive organic electroluminescence device.

##STR00001##

A novel compound having the formula Os(L).sub.3 is disclosed, where Os is osmium(IV) metal, and L is a ligand coordinating to the Os atom, where each L can be same or different, where L is a bidentate ligand, and wherein the compound is neutral.

Disclosed are a transition metal complex, a polymer, a mixture, a composition and the use thereof, wherein the transition metal complex has a structure of the general formula as shown in formula (1):

##STR00001##

The transition metal complex has a novel structure, and is an iridium (III) complex comprising rigid cycloalkyl groups. Since this type of auxiliary ligand increases the rigidity and symmetry of a molecule, the rigidity of a molecule is increased relative to a common ligand without the cycloalkyl groups, and as such, the whole complex has better chemical, optical, electrical and thermal stabilities. At the same time, since the modification occurs on the auxiliary ligand, the effect on the wavelength of the luminous maximum peak caused by a main ligand is relatively low, and therefore, a saturated luminous color may be retained. Therefore, the use of the transition metal complex according to the present invention in OLEDs, in particular as a doping material of a luminous layer, can provide a relatively high luminous efficiency and a relatively long lifetime of the device.

Emissive devices are provided that include a phosphorescent emitter placed within a threshold distance of an enhancement layer to achieve transient lifetimes of 200 ns or less.