A compound containing indolocarbazole having a formula:

##STR00001##

Formula I is disclosed.

A composition that contains an iridium complex and an isomer of the iridium complex, in which the amount of the isomer of the iridium complex is decreased. The iridium complex is a homo-N-trans (HNT) iridium complex having an iridium atom, and a first ligand, a second ligand, and a third ligand that are bonded to the iridium atom. The isomer has an iridium atom, a fourth ligand, a fifth ligand, and the third ligand. The composition ratio of the isomer relative to a total of the iridium complex and the isomer is 1.0% or less.

Tridentate platinum, palladium, and gold complexes of Formulas A-I and A-II and tridentate iridium and rhodium compounds of Formulas B-I, B-II, and B-III suitable for delayed fluorescent and phosphorescent or phosphorescent emitters in display and lighting applications. ##STR00001##

A light-emitting element includes an EL layer between a pair of electrodes. The EL layer contains a first compound and a second compound. The first compound is a phosphorescent iridium metal complex having a LUMO level of greater than or equal to −3.5 eV and less than or equal to −2.5 eV, and the second compound is an organic compound having a pyrimidine skeleton. The light-emitting element includes an EL layer between a pair of electrodes. The EL layer contains a first compound and a second compound. The first compound is a phosphorescent iridium metal complex having a diazine skeleton, and the second compound is an organic compound having a pyrimidine skeleton.

Iridium, rhodium, and platinum complexes suitable for use as phosphorescent emitters or as delayed fluorescent and phosphorescent emitters having the following structures:

##STR00001##

A compound containing indolocarbazole having a formula: ##STR00001##
Formula I is disclosed.

A composition of materials including a first compound having a structure according to Formula I

##STR00001##

Phosphorescent complexes are designed with intramolecular H-bonding properties to prevent deprotonation of neighboring molecules.

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.

Disclosed are organic electrooptic materials. The electrooptic materials are functionalized by novel methods and structures. The electrooptic materials are structured with a head and a tail where the head and tail sequentially assemble into a non-centrosymmetric ordered array. The electrooptic materials are further structured in covalently bonded dimer pairs where one of the pairs is zwitterionic. The non-centrosymmetric ordered array bonds directly to electrodes which allows for efficient application of the electric field. The organic electrooptic materials disclosed offer greater hyperpolarizability, greater bandwidth, reduced operating voltage with less optical loss.