Mercapto-substituted imidazolylporphyrin metal complex monomer, polymer having the same as a repeating unit and method of preparing the same

A method for preparing a porphyrin metal complex monomer represented by formula (1):

• wherein R1 represents a group selected from the group consisting of an alkyl group, unsubstituted aryl group, alkyl-substituted aryl group and alkyloxy-substituted aryl group;
• M represents a metal ion selected from the group consisting of Zn(II), Ga(III), Fe(II), Co(II), and Ru(II):
• X represents a divalent linking group consisting of one or more group selected from the group consisting of an arylene group and an alkylene group;
• R2 represents a hydrogen atom or an acetyl group;
• and Im represents Im1 and Im2 set forth below:
• wherein R3 represents a hydrogen atom or an alkyl group, comprising dissolving a mercapto-substituted imidazolylporphyrin metal complex dimer represented by formula (2):
• wherein each of R1, M, R2, X and Im including R3 has the same meaning as defined above, in a solvent having high polarity.