Organic electroluminescent materials and devices

The invention relates to organic electroluminescent materials and devices. There is provided a compound comprising a first ligand LA comprising a structure of Formula I: In Formula I, moieties A, B, C and D are each independently a monocyclic or polycyclic fused ring system; each of X1 to X8 is C or N; each independently represents a single bond or a double bond; l1, L2, L3 and L4 are each independently a direct bond or a linking group; each R, R ', R' ', RA, RB, RC and RD is hydrogen or a universal substituent; any two adjacent R, R ', R' ', RA, RB, RC, and RD may be joined or fused to form a ring; and LA is coordinated with the transition metal M. Formulations, OLEDs, and consumer products containing the compounds are also provided. 本申请涉及有机电致发光材料和装置。提供一种包含第一配体LA的化合物，所述第一配体LA包含式I的结构：在式I中，部分A、B、C和D各自独立地是单环或多环稠合环系统；X1到X8各自是C或N；各独立地表示单键或双键；L1、L2、L3和L4各自独立地是直接键或连接基团；各R、R'、R"、RA、RB、RC和RD是氢或通用取代基；任何两个相邻R、R'、R"、RA、RB、RC和RD可接合或稠合以形成环；并且LA与过渡金属M配位。还提供含有所述化合物的调配物、OLED和消费型产品。