Blue thermally activated delayed fluorescent emitters and hosts based on functionalized imidazolyl groups

A compound of General Formula I:

• wherein:
• Y1a, Y1b, Y1c, Y2a Y2b, Y2c, and Y2d each independently represents C or N;
• C and E each represent N;
• each A, B, and D independently represent C or N;
• each of Y1 and Y2 is independently absent or present, valency permitting;
• Y1 and Y2 independently represent hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino;
• substituted or unsubstituted:
• aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, or polymeric;
• or any combination thereof;
• or Y1 and Y2 may together form a ring;
• R1 and R2 are independently absent or present, valency permitting, and each R1 and R2 independently represents hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino;
• substituted or unsubstituted:
• aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, or polymeric;
• or any combination thereof;
• any two adjacent R1 and R2 may together form a ring;
• provided that at least two adjacent R2 together represent a group of Formula A:
• wherein:
• waved lines indicate bonds to the respective Y2a, Y2b, Y2c, or Y2d;
• Y3a Y3b, Y3c, and Y3d each independently represents C or N;
• X1 independently represents C, N, Si, O, S, Ge, P, As, Se, B, Al, or Bi, or if valency permits, X1 independently represents CR4, SiR4, GeR4, NR4, P═O, As═O, B, BR4, AlR4, Bi═O, CR4R5, C═O, SiR4R5, GeR4R5, PR4, PR4R5, R4P═O, AsR4, R4As═O, S═O, SO2, Se═O, SeO2, BR4, BR4R5, AlR4, AlR4R5, R4Bi═O, or BiR4;
• R3, R4, and R5 are independently absent or present, valency permitting, and each R3, R4 and R5 independently represents hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino;
• substituted or unsubstituted:
• aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, or polymeric;
• or any combination thereof;
• any two of R1, R2, R3, R4, and R5 may together form a ring;
• each n is an integer, valency permitting;
• and
• wherein at least two adjacent R3 together represent a group of Formula B:
• wherein waved lines indicate bonds to the respective Y3a, Y3b, Y3c, and Y3d;
• Y4a, Y4b, Y4c, and Y4d each independently represents C or N;
• X2 independently represents C, N, Si, O, S, Ge, P, As, Se, B, Al, or Bi, or if valency permits, X2 independently represents CR7, SiR7, GeR7, NR7, P═O, As═O, B, BR7, AlR7, Bi═O, CR7R8, C═O, SiR7R8, GeR7R8, PR7, PR7R8, R7P═O, AsR7, R7As═O, S═O, SO2, Se═O, SeO2, BR7, BR7R8, AlR7, AlR7R8, R7Bi═O, or BiR7;
• each of R6, R7, and R8 is independently absent or present as a single substituent or multiple substituents, valency permitting, and each of R6, R7, and R8 independently represents hydrogen, deuterium, halogen, hydroxyl, thiol, nitro, cyano, nitrile, isonitrile, sulfinyl, mercapto, sulfo, carboxyl, hydrazino:
• substituted or unsubstituted:
• aryl, cycloalkyl, cycloalkenyl, heterocyclyl, heteroaryl, alkyl, alkenyl, alkynyl, amino, monoalkylamino, dialkylamino, monoarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, or polymeric;
• or any combination thereof;
• any two of R6, R7, and R8 may together form a ring;
• and
• n is an integer, valency permitting.