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

A compound of represented by one of the following formulas:

• wherein:
• Y1a represents 0, S, NR4a, wherein R4a represents optionally substituted C1-C4 alkyl;
• or C(R4c)2, wherein each R4c in (R4c)2 represents hydrogen or optionally substituted C1-C4 alkyl;
• Y1b represents 0, S, NR5a, wherein R5a represents optionally substituted C1-C4 alkyl;
• or C(R5c)2, wherein each R5c in (R5c)2 represents hydrogen or optionally substituted C1-C4 alkyl;
• and
• Y3d represents N, O, S, NR6a, CR6b, wherein each of R6a and R6b is independently absent or independently represents hydrogen or optionally substituted C1-C4 alkyl.

A compound represented by the formula:

• wherein:
• each R1 and R2 in (R1)2 and (R2)2 independently represents hydrogen;
• Y1a represents O, S, or NR4a, wherein R4a represents optionally substituted C1-C4 alkyl;
• n is an integer 1;
• Y1b represents O, S, or NR5a, wherein R5a represents optionally substituted C1-C4 alkyl;
• each of Y2a, Y2b, Y2c, and Y2d independently represents N, NR6a, or CR6b, wherein each of R6a and R6b independently represents hydrogen, or optionally substituted C1-C4 alkyl;
• each of Y3a, Y3b, Y3c, Y3d, Y3e, Y4a, Y4b, Y4c, and Y4d independently represents N, O, S, NR6a or CR6b, wherein each of R6a and R6b independently represents hydrogen or optionally substituted C1-C4 alkyl;
• wherein m is an integer 1 or 2;
• wherein the open dotted circle indicates partial or full unsaturation of the ring with which it is associated;
• provided that if m is 1, each of Y2a and Y2d is CH and each of Y2b and Y2c is N, then at least one of Y4a, Y4b, Y3a, or Y3d is not N.