Tetradentate and octahedral metal complexes suitable for use as phosphorescent or delayed fluorescent and phosphorescent emitters in display and lighting applications.

A compound having the structure of Formula I,

##STR00001##

is provided. In Formula I, M is Pt or Pd; moieties A, B, C, and D are each monocyclic or multicyclic ring system; K.sup.1, K.sup.2, K.sup.3, and K.sup.4 are selected from a direct bond, O, S, and Se; when present, each of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 is a direct bond or a linker; at least three of L.sup.1, L.sup.2, L.sup.3, and L.sup.4 are present; and the compound comprises at least one structure

##STR00002##

Formulations, OLEDs and consumer products containing the compound are also provided.

An organometallic compound represented by Formula 1: ##STR00001## wherein, in Formula 1, groups and variables are the same as described in the specification.

Organometallic compounds comprising an imidazole carbene ligand having a N-containing ring fused to the imidazole ring are provided. In particular, the N-containing ring fused to the imidazole ring may contain one nitrogen atom or more than one nitrogen atom. These compounds may demonstrate high photoluminescent (PL) efficiency, Gaussian emission spectra, and/or short excited state lifetimes. These materials may be especially useful as blue phosphorescent emitters.

The present invention relates to a real-time fluorescence imaging sensor for measuring glutathione in cell organelles and a method for fabricating the same. More specifically, the present invention relates to a novel compound for measuring glutathione in cell organelles, a method for preparing the novel compound, a real-time fluorescence imaging sensor for measuring glutathione in cell organelles, which comprises the novel compound, a method for fabricating the imaging sensor, and a method of measuring glutathione in cell organelles by use of the imaging sensor. When the composition comprising the compound according to the present invention is used, it can measure the antioxidant activity of the organelle mitochondria or Golgi apparatus in living cells, particularly stem cells, and can screen highly active stem cells based on the results obtained by measuring the antioxidant activity of the cell organelle.

A compound represented by the following general formula is excellent in light emission properties. R.sup.1 and R.sup.2 each independently represent a fluorinated alkyl group, D represents a substituent in which Hammett's σ.sub.p value is negative, and A represents a substituent in which Hammett's σ.sub.p value is positive. ##STR00001##

The present disclosure relates in part to compounds capable of emitting delayed fluorescence and uses of these compounds in organic light-emitting diodes.

A light-emitting element having high emission efficiency is provided. The light-emitting element includes a first organic compound, a second organic compound, and a third organic compound. The first organic compound has a function of converting triplet excitation energy into light emission. The second organic compound is preferably a TADF material. The third organic compound is a fluorescent compound. Light emitted from the light-emitting element is obtained from the third organic compound. Triplet excitation energy in a light-emitting layer is transferred to the third organic compound by reverse intersystem crossing caused by the second organic compound or through the first organic compound.

A condensed cyclic compound represented by Formula 1:

##STR00001## wherein in Formula 1, Ar and R.sub.1 to R.sub.8 are the same as described in the specification.

A ligand for metal complexes are disclosed, in which an imidazole ring is fused to an aromatic ring as a substituent or an imidazole ring is fused to a six-member ring of the original ligand. The features of these elements within the ligand afford a better device performance in general OLED device.