Organic electroluminescent materials and devices

An organic light emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an organic layer, disposed between the anode and the cathode, comprising a compound having a metal coordination complex structure;
• wherein the compound is capable of functioning as an emitter in an organic light emitting device at room temperature;
• wherein the compound has at least two ligands coordinated to the metal;
• wherein the compound has a first substituent R1 at one of the ligands' periphery;
• wherein a first distance is the distance between the metal and an atom in R1 that is the farthest away from the metal;
• wherein the first distance is longer than any distance between the metal and any other atoms in the compound;
• and
• wherein when a sphere having a radius r is defined whose center is the metal and the radius r is the smallest radius that will allow the sphere to enclose all atoms in the compound that are not part of R1, the first distance is longer than the radius r by at least 2.9 Å.

An organic light emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an emissive layer, disposed between the anode and the cathode, comprising a phosphorescent emitting compound;
• wherein the phosphorescent emitting compound has an intrinsic emission spectrum with a FWHM value of no more than 45 nm;
• wherein the OLED has an EQE of at least 25% measured at 0.1 mA/cm2 at room temperature when a voltage is applied across the device.

A consumer product comprising an organic light-emitting device (OLED) comprising:

• an anode;
• a cathode;
• and
• an organic layer, disposed between the anode and the cathode, comprising a compound having a metal coordination complex structure;
• wherein the compound is capable of functioning as an emitter in an organic light emitting device at room temperature;
• wherein the compound has at least two ligands coordinated to the metal;
• wherein the compound has a first substituent R1 at one of the ligands' periphery;
• wherein a first distance is the distance between the metal and an atom in R1 that is the farthest away from the metal;
• wherein the first distance is longer than any distance between the metal and any other atoms in the compound;
• and
• wherein when a sphere having a radius r is defined whose center is the metal and the radius r is the smallest radius that will allow the sphere to enclose all atoms in the compound that are not part of R1, the first distance is longer than the radius r by at least 2.9 Å.