Abstract: The present invention provides a compound represented by the formula (1) or a salt thereof, or a complex of the compound or the salt with a metal, in the formula (1), A1 represents a chelate group; R1 represents a hydrogen atom or the like; R2 represents a hydrogen atom or the like; and Z1, Z2, Z3, Z4, and Z5 are the same or different and each represent a nitrogen atom or CR3 or the like wherein R3 represents a hydrogen atom or an optionally substituted C1-6 alkyl group or the like; L1 represents a group represented by the formula (3) wherein R13, R14, R15, and R16 are the same or different and each represent a hydrogen atom or the like; L2 represents an optionally substituted C1-6 alkylene group; and L3 represents as optionally substituted C1-6 alkylene group.

Abstract: The present invention provides a compound represented by the formula (1) or a salt thereof, or a complex of the compound or the salt with a metal, in the formula (1), A1 represents a chelate group; R1 represents a hydrogen atom or the like; R2 represents a hydrogen atom or the like; and Z1, Z2, Z3, Z4, and Z5 are the same or different and each represent a nitrogen atom or CR3 or the like wherein R3 represents a hydrogen atom or an optionally substituted C1-6 alkyl group or the like; L1 represents a group represented by the formula (3) wherein R13, R14, R15, and R16 are the same or different and each represent a hydrogen atom or the like; L2 represents an optionally substituted C1-6 alkylene group; and L3 represents an optionally substituted C1-6 alkylene group.