Method for synthesizing zirconium complex

A method for synthesizing a zirconium complex, the method comprising setting a temperature of a mixed solution at a certain temperature or more to synthesize a zirconium complex, the mixed solution being obtained by mixing:

• an organic solvent containing an organic substance having water miscibility;
• a chelating agent solution in which a chelating agent containing a structure represented by General Formula (1) or General Formula (2) is dissolved;
• and
• zirconium dissolved in an acidic solution,
• in General Formula (1), R
• 1, R2, R3, and R4 are each hydrogen (-H) (in this case, none of R5 to R12 is further connected), a —CH— group, a —(CH2)nCH— group, a —N(═O)(CH2)nNCH— group, or a —(CH2)nNC(═O)N— group;
• n is an integer of 0 or more;
• at least two of R5, R6, R7, R8, R9, R10, R11, R12, R13, R14, R15, R16, R17, R18, R19, and R20 are at least two selected from a carboxylic acid, a primary amide, hydroxamic acid, phosphonic acid, phosphoric acid, sulfonic acid, an alcohol, an amine, phenol, aniline, and an ester, a secondary amide, hydroxamic acid, and a phosphate that are each obtained by adding a substituent to the aforementioned, with the residual substituents being each hydrogen, an alkyl chain, a tert-butyl blocked carboxylic acid, nitrobenzene, or a substituent-added alkyl chain. a PET probe or a functional group facilitating bonding of a PET probe is optionally added to a functional group contained in R5 to R20;
• the functional group facilitating bonding is a carboxylic acid, a succinimide carboxylate, a tetrafluorophenol carboxylate, an alcohol, an amine, a thiol, an isothiocyanate, maleimide, phenol, aniline, benzoic acid, phenyl isothiocyanate, or an alkyne, an azide, dibenzocyclooctyne (DBCO), bicyclononyne (BCN), trans-cyclooctene (TCO), norbornene, tetrazine, or methyltetrazine, which are each a click chemistry reagent;
• and R5 to R20 optionally have a structure of the functional group facilitating bonding or a condensed structure of a PET probe and the functional group facilitating bonding, and
• in General Formula (2), R21, R22, and R23 are each hydrogen (-H) (in this case, none of R24 to R29 is further connected), a —CH— group, a —(CH2)nCH— group, a —N(═O)(CH2)nNCH— group, or a —(CH2)nNC(═O)N— group;
• n is an integer of 0 or more;
• at least two of R24, R25, R26, R27, R28, R29, R30, R31, R32, R33, R34, and R35 are at least two selected from a carboxylic acid, a primary amide, hydroxamic acid, phosphonic acid, phosphoric acid, sulfonic acid, an alcohol, an amine, phenol, aniline, and an ester, a secondary amide, hydroxamic acid, and a phosphate that are each obtained by adding a substituent to the aforementioned, with the residual substituents being each hydrogen, an alkyl chain, a tert-butyl blocked carboxylic acid, nitrobenzene, or a substituent-added alkyl chain. a PET probe or a functional group facilitating bonding of a PET probe is optionally added to a functional group contained in R24 to R35;
• the functional group facilitating bonding is the following functional group:
• a carboxylic acid, a succinimide carboxylate, a tetrafluorophenol carboxylate, an alcohol, an amine, a thiol, an isothiocyanate, maleimide, phenol, aniline, benzoic acid, phenyl isothiocyanate, or an alkyne, an azide, DBCO, BCN, TCO, norbornene, tetrazine, or methyltetrazine, which are each a click chemistry reagent;
• and R24 to R35 optionally have a structure of the functional group facilitating bonding or a condensed structure of a PET probe and the functional group facilitating bonding.