ORGANOMETALLIC IRIDIUM COMPLEX, LIGHT-EMITTING ELEMENT, LIGHT-EMITTING DEVICE, ELECTRONIC DEVICE, AND LIGHTING DEVICE

摘要

An organometallic iridium complex has high emission efficiency and a long lifetime. The iridium complex includes the structure represented by Formula (G1). In the formula, Ar represents a substituted or unsubstituted arylene group having 6 to 13 carbon atoms. R1 to R6 independently represent any one of hydrogen and a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, and one of R2 and R6 represents the alkyl group. X represents a carbon atom or a nitrogen atom, and when X represents a carbon atom, hydrogen or an alkyl group having 1 to 6 carbon atoms is bonded to the carbon atom. A dihedral angle between a ring bonded to R1 and a phenyl group bonded to R2 to R6 is 30° or more and 90° or less. An interior angle of the pyridine/pyrimidine ring facing R1 is within a range of 118° of 122°.