Element having porphyrin polymer fixed on a substrate and method of preparing the same

A method of preparing a photo-functional molecule element having, on a substrate, a porphyrin polymer containing covalently-fixed porphyrin units, which method comprises:

• (1) fixing, on a substrate, a linker molecule represented by the following formula (I):
• 71
• [wherein
• a, b and d independently represent H, an alkyl group or an aryl group;
• X represents —O—, —S—, >NR101 (wherein R101 represents H or an alkyl group), —CH2— or a single bond;
• Y represents ═O, ═S or 2H;
• m represents an integer of 0 to 4;
• n represents an integer of 0 to 6;
• Z1 represents a 5- or 6-membered nitrogen-containing heteroaromatic ring group capable of forming a coordination bond;
• and
• R1 represents
• 72
• (wherein D represents a divalent group including at least one of arylene group and alkylene group;
• E represents a trivalent group including at least one of arylene group and alkylene group;
• and R3 represents H or an acetyl group)];
• and
• introducing a metal, M, selected from the group consisting of typical metals and transition metals to the porphyrin residue derived from the linker molecule,
• thereby obtaining a monomolecular film represented by the following formula (II) or (II′):
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• (wherein each of the substituents is as defined above),
• provided that either one of the fixing a linker molecular and the introducing a metal M may be carried out earlier than the other;
• (2) linking the porphyrin residue of the monomolecular film with one of porphyrin residues of meso-meso linked bis-porphyrin represented by the following formula (III):
• 74
• (wherein each of a, b, d, X, Y, m, n, M and Z1 is as defined above and Q represents a single bond or divalent linking group), via two coordinate bonds, thereby obtaining a first laminate represented by the following formula (IV) or (IV′):
• 75 76
• (wherein each of the substituent is as defined above, and p is 1);
• (3) effecting, in the presence of a Grubbs catalyst, a ring-closing metathesis reaction of the olefin portions of the porphyrin residue derived from the linker molecule, with the corresponding olefin portions of the porphyrin residue that is coordinated to the linker molecule, so that the porphyrins are fixed to each other by covalent bonds, thereby obtaining a fixed first laminate represented by the following formula (V) or (V′):
• 77 78
• (wherein each of the substituents is as defined above, and p is 1);
• (4) optionally,
• linking the porphyrin residue at the terminal end of the fixed first laminate with one of the porphyrin residues of another meso-meso linked bis-porphyrin represented by the formula (III), via two coordinate bonds, in the same manner as in above (2), thereby obtaining a second laminate represented by the above formula (IV) or (IV′), wherein p represents an integer of 2 or more);
• and
• effecting, in the presence of a Grubbs catalyst, a ring-closing metathesis reaction in the same manner as in above (3), thereby obtaining a fixed second laminate represented by the formula (V) or (V′), wherein p represents an integer of 2 or more);
• wherein the linking and the effecting the ring-closing metathesis reaction, as one cycle, are sequentially repeated q times, thereby obtaining a fixed qth laminate represented by the formula (V) or (V′), wherein p represents q, and q is an integer of 2 or more;
• (5) linking the porphyrin residue at the terminal end of the fixed first laminate obtained in above (3) or the fixed qth laminate obtained in above (4), with the porphyrin residue of a porphyrin derivative represented by the following formula (VI):
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• (wherein each of Z1, M, X, Y, m, n, a, b and d is as defined above, and Z2 represents a group having a functional group which can be an electron acceptor or electron donor, or a group which can be the terminal group of the porphyrin polymer), via two coordinate bonds, thereby obtaining a photo-functional molecule precursor represented by the following formula (VII) or (VII′):
• 80 81
• (wherein each of the substituents is as defined above);
• and
• (6) effecting, in the presence of a Grubbs catalyst, a ring-closing metathesis reaction of the olefin portion derived from the porphyrin derivative represented by the formula (VI), with the olefin portion of the porphyrin residue that is coordinated to the porphyrin derivative, so that the porphyrins are fixed to each other by covalent bonds, thereby obtaining a photo-functional molecule element represented by the following formula (VIII) or (VIII′):
• 82 83
• (wherein each of the substituents is as defined above).