An electrochromic compound having a structure represented by the following general formula (1): where each of X.sub.1 to X.sub.3 independently represents a carbon atom or a silicon atom, and each of R.sub.1 to R.sub.15 independently represents a member selected from the group consisting of a hydrogen atom, a halogen atom, a monovalent organic group, and a polymerizable functional group. ##STR00001##

A composition which is useful for producing a light emitting device having excellent external quantum efficiency and a light emitting device containing the composition are described. The light emitting device contains an anode, a cathode, and an organic layer disposed between the anode and the cathode and contains a composition containing at least two compounds (A) selected from the group consisting of a compound represented by the formula (FH) and a polymer compound containing a constitutional unit having a group obtained by removing from a compound represented by the formula (FH) one or more hydrogen atoms, and a compound (B) having a condensed hetero ring skeleton (b) containing a boron atom and a nitrogen atom in the ring.

##STR00001##

The present disclosure provides a new series of compounds exhibiting high fluorescence quantum yields in the solid state. In one embodiment, the compounds include a series of 2,3,4,5-tetraphenylgermoles with the same or different 1,1-substituents. In another embodiment, substituted germafluorenes, germa-fluoresceins/rhodamines, and germapins are described. These germanium heterocycles possess ideal photophysical and thermostability properties, which makes them excellent candidates for chemical or biological sensors, host materials for electroluminescent devices and solar cells, and emissive and/or electron-transport layer components in organic light emitting diode devices.

The present invention relates to dinuclear metal complexes and to electronic devices, especially organic electroluminescent devices, comprising these metal complexes.

A compound having a structure of the formula Ir(L.sub.A)(L.sub.B), in which L.sub.A is a bidentate, tridentate, tetradentate, pentadentate, or hexadentate ligand and L.sub.B is a monodentate, bidentate, tridentate, or tetradentate ligand, or not present, and where the total denticity of L.sub.A plus L.sub.B is 6, and L.sub.A includes at least one structure of Formula I: ##STR00001##
is disclosed as a useful phosphorescent emitter compound.

An organic light emitting diode (OLED) including at least one emitting material layer (EML) disposed between two electrodes and comprising a first compound including a fused ring of boron and oxygen as a nuclear atom and a second compound including a fused ring of born and nitrogen as a nuclear atom and an organic light emitting device including the OLED is disclosed. The first compound and the second compound may be the same emitting material layer or adjacently disposed emitting material layers. The OLED can lower its driving voltage and improve its luminous efficiency using the first and second compounds with adjusting their energy levels.

The present invention provides: a curable composition which contains a bismuth compound, wherein a phosphoric acid ester having a (meth)acryloyl group is bonded to bismuth, and a nitrile compound having a radically polymerizable carbon-carbon double bond; a cured body which is obtained by curing this curable composition; a multilayer body which is composed of the above-described cured body and a cured body that is obtained by curing a photochromic curable composition; and a radiation protective material which is formed of the above-described cured body or the above-described multilayer body.

Platinum, palladium, and gold complexes suitable for use as phosphorescent emitters or as delayed fluorescent and phosphorescent emitters having one of the following structures:

##STR00001## ##STR00002##

The present invention relates to a compound suitable as ligand for binding to the surface of a semiconductor nanoparticle, said compound comprising an anchor group, a linker group and an organic functional group; a semiconductor nanoparticle have said ligand attached to the outermost particle surface; a composition, a formulation and a process for the preparation of said semiconductor nanoparticle; and an electronic device.

With a light-emission-layer material comprising: a novel polycyclic aromatic compound (1) or a multimer thereof in which a plurality of aromatic rings are linked by a boron atom and a nitrogen atom; and a specific anthracene-based compound (3) that achieves optimum light-emission characteristics in combination with said polycyclic aromatic compound or a multimer thereof, it is possible to provide an organic EL element having optimum light-emission characteristics. ##STR00001## Ring A to ring C are an aryl ring or the like, Y.sup.1 represents B, X.sup.1 and X.sup.2 represent N—R, R of the N—R is an aryl or the like, and Ar.sup.3 and Ar.sup.4 are a hydrogen atom, a phenyl, a group represented by formula (4), or the like.