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 first compound;
• wherein the first compound is capable of functioning as a phosphorescent emitter in an organic light emitting device at room temperature;
• wherein the first compound has at least one aromatic ring and at least one substituent R;
• wherein each of the at least one substituent R is directly bonded to one of the at least one aromatic ring;
• wherein each of the at least one substituent R has the formula of
• wherein
• (a) G1 is selected from the group consisting of NR1, SiR1R2, Ge R1R2, alkyl, cycloalkyl, and combinations thereof;
• and G2 is a non-aromatic polycyclic group, which can be further substituted by one or more R3;
• (b) G1 is a direct bond;
• and G2 is a non-aromatic spiro polycyclic group, which can be further substituted by one or more R3;
• or
• (c) G1 is selected from the group consisting of:
• direct bond, NR1, SiR1R2, Ge R1R2, alkyl, cycloalkyl, and combinations thereof;
• G2 is a non-aromatic polycyclic group, which can be further substituted by one or more R3;
• and R is directly bonded to an aromatic ring selected from the group consisting of phenyl, pyridine, and triazine, which can be further fused to other rings;
• wherein R1, R2, and R3 are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof;
• and
• wherein each G1 and G2 is independently, optionally, partially or fully deuterated.