Recently, we reported synthesis of porphyrin/phthalocyanine conjugates linked by fourfold rotaxane. In the conjugate, a porphyrin and a phthalocyanine formed a heterodimer in a cofacial fashion (Fig. 1a). [1] The conjugate is a promising platform for supramolecular catalysts based on dinuclear porphyrinoid complexes, because various metal ions to be a functional center are able to be arrayed in the conjugate regioselectively to afford homo- and hetero-dinuclear centers in the conjugate. [2,3] Moreover, these arrays were expanded to hetero-trinuclear arrays (Fig. 1b). [3-6]

In this paper, we will present regioselective metal arraying in the conjugate and the supramolecular catalytic functions (Fig. 2). One of the methods to prepare the hetero-dinuclear complexes was to use the difference of metalation rate between porphyrin and phthalocyanine. We found reaction conditions for porphyrin-selective Fe(II) or Ni(II) insertion and phthalocyanine-selective Mn(II) insertion. Subsequent metalation to another porphyrinoid in the conjugate gave a hetero-dinuclear complex. We used these multinuclear complexes in the conjugate as catalysts. The dinuclear iron complex exhibited good catalytic activity in electrochemical reduction of molecular oxygen to water. [7]

References:

1) Y. Yamada, M. Okamoto, K. Furukawa, T. Kato, and K. Tanaka., Angew. Chem. Int. Ed., 51, 709 (2012,).

2) Y. Yamada, N. Mihara, and K. Tanaka., Dalton Trans., 42, 15873 (2013).

3) N. Mihara, Y. Yamada, and K. Tanaka., submitted.

4) Y. Yamada, N. Mihara, S. Shibano, K. Sugimoto, and K. Tanaka., J. Am.Chem. Soc., 135, 11505 (2013).

5) Y. Yamada, S. Akine, K. Sugimoto, and K. Tanaka, Chem. Euro. J., 22, 12371 (2016).

6) N. Mihara, Y. Yamada, S. Akine, K. Sugimoto, and K. Tanaka., submitted.

7) N. Mihara, Y. Yamada, and K. Tanaka., submitted.