Photochemistry and Photobiology, 2014, 90 127
folded conformer of 2P would give a red side of the Qy band.
The spectral analysis indicated that 2P partially formed the
folded conformer mentioned above. The fact that a zinc porphy-
rin had less coordination ability than the corresponding zinc
chlorin also suppressed the folding of 2P. The Soret band of 2P
was largely shifted to a shorter wavelength than that of 3P (435
? 416 nm), and the face-to-face folding through H-type aggre-
gation may occur due to the extremely flat porphyrin planes.
photosynthetic apparatus and their synthetic models composing
of porphyrinoids.
Acknowledgements—We thank Mr. Katsunori Nishide of Ritsumeikan
University for his experimental assistance. This work was partially
supported by Grants-in-Aid for Scientific Research (A) (no. 22245030) as
well as on Innovative Areas “Artificial Photosynthesis (AnApple)” (no.
24107002) from the Japan Society for the Promotion of Science (JSPS).
Supramolecular structure of methanol-locked Chl dyad
conformer
SUPPORTING INFORMATION
Additional Supporting Information may be found in the online
version of this article:
Figure S1. Qy absorption spectra of monomer 3a and dyads
4(n) (ca. 10À5 M) in 1% (v/v) methanol and benzene.
Figure S2. Difference between 1H chemical shifts of 1bb in
C6D6 containing 1% (v/v) CD3OD and C5D5N.
In the folded conformer of zinc Chl derivative dyads, the central
zinc atoms were coordinated by a methanol molecule as an axial
ligand to give a five-coordinated species. It is known that the
chlorin p-plane of Chl derivatives has two faces, a- and b-faces
(25). In the folded conformer, the five-coordinated zinc took
either a- or b-ligation and four stereoisomers are proposed for the
coordination sites, a,a-, a,b-, b,a- and b,b-ligation (see Fig. 10,
upper). The stereochemistry in the folded conformer was identi-
fied by the following 1H NMR measurements. In 1% (v/v)
CD3OD–CDCl3, hetero-dyad 1ad was analyzed by 1D and 2D
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