This invention relates to compounds containing heterocycles or azaheterocycles and phenylene or azaphenylene wherein at least one ring is a five-membered ring. These novel compounds are useful as host materials for phosphorescent electroluminescent devices.

A phosphorescent emitter or delayed fluorescent and phosphorescent emitters represented by Formula I or Formula II, where M is platinum or palladium.

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Provided herein are rigid macrocycles comprising a poly(peri-naphthalene) diimide (PPNDI) submit and a second diimide subunit having both high photoluminescent and electron accumulation activities. Also provided herein are methods of preparation of the rigid macrocycles and methods of using the same.

An organic light-emitting device having improved efficiency and lifespan includes: a first electrode, a second electrode, and an organic layer between the first electrode and the second electrode, wherein the organic layer includes an emission layer, the emission layer includes a first compound, a second compound, a third compound, and a fourth compound, the first compound, the second compound, the third compound, and the fourth compound are different from each other, the third compound includes a metal element having an atomic number of 40 or more, the fourth compound includes boron (B), the third compound and the fourth compound each satisfy Conditions 1-1 and 1-2 below, and the fourth compound satisfies Condition 2 or 3:

T.sub.1(C3).sub.onset≥S.sub.1(C4).sub.onset  Condition 1-1

T.sub.1(C3).sub.max≥S.sub.1(C4).sub.max  Condition 1-2

K.sub.RISC(C4)≥10.sup.3S.sup.−1  Condition 2

f(C4)≥0.1.  Condition 3

The invention relates to an organic molecule for optoelectronic devices. According to the invention, the organic molecule has a structure of Formula I:

##STR00001## wherein X.sup.1, X.sup.2, X.sup.3, X.sup.4, X.sup.5, X.sup.6, X.sup.7, X.sup.8, X.sup.9, X.sup.10, X.sup.11, X.sup.12, X.sup.13, and X.sup.14 is independently selected from the group consisting of N and CR.sup.a; and Z is at each occurrence independently selected from the group consisting of a direct bond, CR.sup.3R.sup.4, CCR.sup.3R.sup.4, CO, CNR.sup.3, NR.sup.3, O, SiR.sup.3R.sup.4, S, S(O), and S(O).sub.2.

An organic electroluminescent device having an anode, a cathode, and a light emitting layer between the anode and the cathode, in which the light emitting layer contains a first organic compound, a second organic compound, and a third organic compound that satisfy the following expression (A), the second organic compound is a delayed fluorescent material, and the third organic compound is a light emitting material, is capable of enhancing the light emission efficiency. E.sub.S1(A), E.sub.S1(B) and E.sub.S1 (C) represent a lowest singlet excitation energy level of the first, second and third organic compound, respectively.

E.sub.S1(A)>E.sub.S1(B)>E.sub.S1(C)(A)

A phosphorescent emitter or delayed fluorescent and phosphorescent emitters represented by Formula I or Formula II, where M is platinum or palladium. ##STR00001##

The synthesis and characterization of a platinum (II) terpyridine system tethered with a latent organic dye of rhodamine derivative as colorimetric and fluorescent sensory moiety has been reported to show selective Hg.sup.2+ ion sensing behavior. The interplay of aggregation/de-aggregation behavior of the alkynylplatinum(II) terpyridine complex and the ring-opening process of rhodamine derivative has been investigated. The spectral change of aggregation NIR emission at 800 nm and rhodamine fluorescence at 585 nm provides a possible ratiometric luminescence measurement. Morphological studies from TEM and SEM images showing nanospherical structures confirmed the aggregation in the absence of Hg.sup.2+ ion.

Provided are an organometallic compound represented by Formula 1, an organic light-emitting device including the organometallic compound, and a diagnostic composition including the organometallic compound.

M.sub.1(L.sub.11).sub.n11(L.sub.12).sub.n12<Formula 1>

L.sub.11 in Formula 1 is a ligand represented by Formula 1-1, the organometallic compound comprises at least one cumyl group, and the other substituents are the same as described in connection with the detailed description of the specification:

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The present invention relates to mechanically linked emitter-emitter, host-host, and emitter-host materials. These materials may be useful in organic electroluminescence devices.