Abstract: A novel light-emitting material is provided. A novel orgnometallic complex is provided. An orgnometallic complex having a high carrier-transport property is provided. An orgnometallic complex having a deep HOMO level and/or a deep LUMO level is provided. An orgnometallic complex having a high charge-injection property is provided. Another object is to provide an organometallic complex that can exhibit yellow to blue phosphorescence. An organometallic complex that has a high carrier-transport property and exhibits green to blue phosphorescence is provided. An organometallic complex including a ligand having a structure of 5-(2-pyridinyl)-5H-benzimidazo[1,2-a]benzimidazole and a light-emitting material including the organometallic complex are provided.

Abstract: Provided is a light-emitting element with high emission efficiency. The light-emitting element includes a first organic compound, a second organic compound, and a guest material. The LUMO level of the first organic compound is lower than that of the second organic compound, and the HOMO level of the first organic compound is lower than that of the second organic compound. The LUMO level of a guest material is higher than that of the first organic compound, and the HOMO level of the guest material is lower than that of the second organic compound. The guest material has a function of converting triplet excitation energy into light emission. The first organic compound and the second organic compound form an exciplex.

Abstract: An organometallic complex that has high emission efficiency and high heat resistance and emits blue light is provided as a novel substance. In a light-emitting element including a light-emitting layer between a pair of electrodes, the light-emitting layer includes an organometallic complex, and the organometallic complex includes a central metal and two types of ligands coordinated to the central metal. One of the two types of ligands includes a triazole skeleton including nitrogen bonded to the central metal, and the other includes a nitrogen-containing five-membered heterocyclic skeleton including carbene carbon bonded to the central metal and nitrogen bonded to carbene carbon.

Abstract: The organic compound represented by Formula G1 below has a structure in which the 2-position of a dibenzoquinazoline ring is directly, or via one or more arylene groups, bonded to a skeleton with a hole-transport property. In the formula, n represents any of 0 to 3, m represents 1 or 2, A represents a single bond, or a substituted or unsubstituted arylene group having 6 to 13 carbon atoms, B represents a ring having a substituted or unsubstituted dibenzofuran skeleton, a substituted or unsubstituted dibenzothiophene skeleton, or a substituted or unsubstituted carbazole skeleton, and each of R1 to R14 independently represents any of hydrogen, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, a substituted or unsubstituted cycloalkyl group having 5 to 7 carbon atoms, and a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

Abstract: An object is to provide a novel organometallic complex. Another object is to provide an organometallic complex exhibiting green to blue phosphorescence. Another object is to provide an organometallic complex having deep HOMO and exhibiting green to blue phosphorescence. Another object is to provide a light-emitting element with high emission efficiency. Another object is to provide a light-emitting element exhibiting green to blue phosphorescence and having low drive voltage. To provide an organometallic complex which includes a 1,2,4-triazole skeleton and in which an N-carbazolyl group is bonded to the 3-position of the 1,2,4-triazole skeleton via a phenylene group, a phenyl group is bonded to the 4-position of the 1,2,4-triazole skeleton, the 2-position of the 1,2,4-triazole skeleton coordinates to iridium, and the phenylene group is bonded to the iridium. To provide a light-emitting element including the organometallic complex as an emission center.

Abstract: To provide a long-lifetime organometallic iridium complex exhibiting yellow light emission with high emission efficiency as a novel substance. The organometallic iridium complex includes a ligand in which an unsubstituted phenyl group is bonded to each of the 2-position and the 5-position of pyrimidine. The organometallic iridium complex has a structure represented by General Formula (G1).

Abstract: Provided is a novel heterocyclic compound, a novel heterocyclic compound that can be used in a light-emitting element, or a highly reliable light-emitting device, electronic device, and lighting device in each of which the light-emitting element using the novel heterocyclic compound is used. One embodiment of the present invention is a heterocyclic compound represented by General Formula (G1). In General Formula (G1), each of A1 and A2 independently represents nitrogen or carbon bonded to hydrogen, and at least one of A1 and A2 represents nitrogen; Ar represents a substituted or unsubstituted arylene group having 6 to 18 carbon atoms; B represents a substituted or unsubstituted fluorenyl group; and R1 represents hydrogen, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 13 carbon atoms.