| 主权项 |
1. A compound comprising a ligand L selected from the group A consisting of: wherein each X1 to X13 are independently selected from the group consisting of carbon and nitrogen; wherein X is selected from the group consisting of BR, NR, PR, O, S, Se, C═O, S═O, SO2, CRR′, SiRR′, and GeRR′; wherein R and R′ are optionally fused or joined to form a ring; wherein each Ra, Rb, Rc, and Rd may represent from mono substitution to the possible maximum number of substitution, or no substitution; wherein each R, R′, Ra, Rb, Rc, and Rd are independently selected from the group consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinations thereof; wherein when Ra, Rb, Rc, and Rd represent at least di substitution, each of the two adjacent Ra, two adjacent Rb, two adjacent Rc, and two adjacent Rd are optionally fused or joined to form a ring; wherein the ligand L is coordinated to a metal M; wherein the ligand L is optionally linked with other ligands to comprise a tridentate, tetradentate, pentadentate or hexadentate ligand; wherein the compound comprises at least one intramolecular hydrogen bonding interaction as shown in the scheme:
Z1—H----Z2, scheme 1; wherein Z1 is selected from the group consisting of carbon, silicon, nitrogen, and oxygen; wherein Z2 is selected from the group consisting of nitrogen, oxygen, and fluorine; and wherein in scheme 1, the proton NMR chemical shift of H is shifted downfield by at least 1.3 ppm compared to the compound when Z2 is carbon. |
