Synthesis of four coordinated palladium complexes and their applications in light emitting devices thereof

A compound represented by the formula:

• wherein:
• each R1 and R2 in (R1)2 and (R2)2 independently represents hydrogen;
• Y1a represents O;
• n is an integer 0;
• each of Y2a Y2b Y2c and Y2d independently represents N, C, or CH;
• each of Y3a, Y3b, Y3c, Y3d, and Y3e independently represents N, NR6a, C or CR6b, wherein each of R6a and R6b independently represents hydrogen or optionally substituted C1-C4 alkyl, and the ring which comprises the Y3a, Y3b, Y3c, Y3d, and Y3e groups is a heteroaryl group having one or two nitrogen atoms, wherein the heteroaryl group is unsubstituted or substituted with one or more optionally substituted C1-C4 alkyl;
• each of Y4a, Y4b, Y4c, and Y4d independently represents N, NR6a, C or CR6b, wherein each of R6a and R6b independently represents hydrogen or optionally substituted C1-C4 alkyl, and the ring which comprises the Y4a, Y4b, Y4c, and Y4d groups is a heteroaryl group having one or two nitrogen atoms, wherein the heteroaryl group is unsubstituted or substituted with one or more optionally substituted C1-C4 alkyl;
• m is an integer 1.