Provided is a compound of Formula I

##STR00001##

in which at least one moiety A, moiety B, moiety C, or moiety D is a 6-membered carbocyclic or heterocyclic ring, and at least one R.sup.A, R.sup.B, R.sup.C, or R.sup.D includes a group having Formula II

##STR00002##

where R.sup.X can be silyl, germyl, boryl, nitrile, F, CF.sub.3, cycloalkyl, heterocycloalkyl, or monocyclic heteroaryl. The compounds are useful as emitters in OLEDs providing improved efficiency.

Provided is a compound of Formula I

##STR00001##

in which at least one moiety A, moiety B, moiety C, or moiety D is a 6-membered carbocyclic or heterocyclic ring, and at least one R.sup.A, R.sup.B, R.sup.C, or R.sup.D includes a group having Formula II

##STR00002##

where R.sup.X can be silyl, germyl, boryl, nitrile, F, CF.sub.3, cycloalkyl, heterocycloalkyl, or monocyclic heteroaryl. The compounds are useful as emitters in OLEDs providing improved efficiency.

An organic electroluminescence device including: a cathode; an anode; and at least one emitting layer disposed between the cathode and the anode, wherein the emitting layer contains a first host material, a second host material, and a dopant material, wherein the first host material is a compound represented by the following formula (1), the second host material is a compound represented by the following formula (2), and the first host material and the second host material are different compounds.

##STR00001##

An organic compound is disclosed comprising: a first chemical moiety with a structure of formula I

##STR00001##

and two second chemical moieties, independently from another with a structure of formula II,

##STR00002##

wherein the first chemical moiety is linked to each of the two second chemical moieties via a single bond.

An organic compound is disclosed comprising: a first chemical moiety with a structure of formula I

##STR00001##

and two second chemical moieties, independently from another with a structure of formula II,

##STR00002##

wherein the first chemical moiety is linked to each of the two second chemical moieties via a single bond.

An organic electroluminescence device includes an anode, a cathode, a first emitting layer, and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer includes, as a first host material, a first compound that includes at least one group represented by a formula (11) below, the first compound being represented by a formula (1) below, the second emitting layer includes a second compound represented by a formula (2) below as a second host material, and the first emitting layer is in direct contact with the second emitting layer. L.sub.101 is a single bond or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms. Ar.sub.101 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. mx is 0, 1, 2, 3, 4, or 5.

##STR00001##

An organic electroluminescence device includes an anode, a cathode, a first emitting layer, and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer includes, as a first host material, a first compound that includes at least one group represented by a formula (11) below, the first compound being represented by a formula (1) below, the second emitting layer includes a second compound represented by a formula (2) below as a second host material, and the first emitting layer is in direct contact with the second emitting layer. L.sub.101 is a single bond or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms. Ar.sub.101 is a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms. mx is 0, 1, 2, 3, 4, or 5.

##STR00001##

An organic electroluminescence device includes: an anode; a cathode; a first emitting layer; and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer contains, as a first host material, a first compound that has at least one group represented by a formula (11) below and that is represented by a formula (1) below, the second emitting layer contains, as a second host material, a second compound represented by one of formulae (2-1A) to (2-4A) below, and the first emitting layer and the second emitting layer are in direct contact with each other.

##STR00001## ##STR00002##

An organic electroluminescence device includes: an anode; a cathode; a first emitting layer; and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer contains, as a first host material, a first compound that has at least one group represented by a formula (11) below and that is represented by a formula (1) below, the second emitting layer contains, as a second host material, a second compound represented by one of formulae (2-1A) to (2-4A) below, and the first emitting layer and the second emitting layer are in direct contact with each other.

##STR00001## ##STR00002##

An organic electroluminescence device includes an anode, a cathode, a first emitting layer, and a second emitting layer provided between the first emitting layer and the cathode, in which the first emitting layer contains, as a first host material, a first compound represented by a formula (1) below and having a group represented by a formula (11) below, the second emitting layer contains a second compound represented by one of formulae (2-1D) to (2-4D) below as a second host material, and the first emitting layer is in direct contact with the second emitting layer.

##STR00001## ##STR00002##