Organic electroluminescent materials and devices

A compound of Formula IwhereinZ1, Z2, Z3, and Z4 are independently selected from C or N; wherein one of Z1 or Z3 is N and the other is C, and one of Z2 or Z4 is N and the other is C; andif Z3 and Z4 are N, then one of RB and one of RC is selected from the group consisting of aryl, substituted aryl, heteroaryl, and substituted heteroaryl; or if Z1 and Z2 are N and, then one of RA, one of RB or one of RC is selected from the group consisting of an optionally substituted aryl, and an optionally substituted heteroaryl. An organic light emitting diode/device (OLED) that includes an anode, a cathode, and an organic layer disposed between the anode and the cathode. The organic layer includes a compound of Formula I above. The OLED can be incorporated into a consumer product, an electronic component module, and/or a lighting panel.