Tetradentate platinum and palladium complex emitters containing phenyl-pyrazole and its analogues

A compound of Formula II:

• wherein M is platinum or palladium,
• wherein L1 represents a substituted or unsubstituted pyrazole,
• wherein L2 represents a substituted or unsubstituted phenyl,
• wherein L3 represents a substituted or unsubstituted 6-membered aryl,
• wherein L4 represents a substituted or unsubstituted 5-membered heteroaryl having 1, 2, or 3 nitrogen atoms,
• wherein each of F1, F2, F3, and F4 is independently present or absent, wherein at least one of F1, F2, F3, and F4 is present, and each of F1, F2, F3, and F4 present is independently selected from aromatic hydrocarbons and their derivatives, polyphenyl hydrocarbons, hydrocarbons with condensed aromatic nuclei, naphthalene, anthracene, phenanthrene, chrysene, pyrene, triphenylene, perylene, acenapthene, tetracene, pentacene, tetraphene, coronene, fluorene, biphenyl, p-terphenyl, o-diphenylbenzene, m-diphenylbenzene, p-quaterphenyl, benzo[a]tetracene, benzo[k]tetraphene, indeno[1,2,3-cd]fluoranthene, tetrabenzo[de,hi,op,st]pentacene, arylethylene, arylacetylene and their derivatives, diarylethylenes, diarylpolyenes, diaryl-substituted vinylbenzenes, distyrylbenzenes, trivinylbenzenes, arylacetylenes, functional substitution products of stilbene, substituted or unsubstituted five-, six- or seven-membered heterocyclic compounds, furan, thiophene, pyrrole and their derivatives, aryl-substituted oxazoles, 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, aryl-substituted 2-pyrazolines and pyrazoles, benzazoles, 2H-benzotriazole and its substitution products, heterocycles with one, two or three nitrogen atoms, oxygen-containing heterocycles, coumarins and their derivatives, miscellaneous dyes, acridine dyes, xanthene dyes, oxazines, and thiazines,
• wherein each F1, F2, F3, and F4, if present, is independently connected to the respective L1, L2, L3, and L4 covalently via a direct bond;
• wherein A is CR1R2, SiR1R2, O, or S,
• wherein each of V1 and V4 is coordinated with M and is N,
• wherein each of V2 and V3 is coordinated with M and is C,
• wherein Y1, Y2, and Y3 are C;
• wherein Y4 is N,
• wherein Ra is present or absent, wherein Rb is present or absent, wherein Rc is present or absent, wherein Rd is present or absent, and if present each of Ra, Rb, Rc, and Rd independently represents mono-, di-, or tri-substitutions, and wherein each of Ra, Rb, Rc, and Rd is independently 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, polymeric;
• or any conjugate or combination thereof, and
• wherein each of R1 and R2 is independently 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, monarylamino, diarylamino, alkoxy, aryloxy, haloalkyl, aralkyl, ester, alkoxycarbonyl, acylamino, alkoxycarbonylamino, aryloxycarbonylamino, sulfonylamino, sulfamoyl, carbamoyl, alkylthio, ureido, phosphoramide, silyl, polymeric;
• or any conjugate or combination thereof.