Organic electroluminescent materials and devices

A first device comprising a first organic light emitting device, the first organic light emitting device comprising:

• an anode;
• a cathode;
• and
• an organic layer, disposed between the anode and the cathode, comprising a composition of materials comprising a first compound, wherein the first compound has a formula:
• wherein G2, G3, and, when present, G4 are each optionally further substituted with one or more unfused substituents selected from the group consisting of deuterium, alkyl, alkoxyl, cycloalkyl, cycloalkoxyl, halogen, nitro, nitrile, silyl, phenyl, biphenyl, terphenyl, pyridine, and combinations thereof;
• and
• wherein
• (A) when m=0, L1 is biphenyl, L2 is a direct bond, L3 is a direct bond,
• G1 is selected from the group consisting of dibenzoselenophene and fluorene, and
• G2 and G3 are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof;
• and
• (B) when m is 1 to 7, G1 is selected from the group consisting of dibenzofuran, dibenzothiophene, dibenzoselenophene, and fluorene, and each G4 is independently selected from the group consisting of phenyl, and biphenyl, and at least one G4 is biphenyl,
• wherein L1, L2 and L3 are each independently selected from the group consisting of direct bond, phenyl, biphenyl, terphenyl, pyridine, pyrimidine, and combinations thereof, and
• G2 and G3 are each independently selected from the group consisting of phenyl, biphenyl, terphenyl, fluorene, naphthalene, phenanthrene, pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, phenanthroline, aza-fluorene, and combinations thereof.