ces in the long-wavelength visible and near-infrared regions
were enhanced in the COFs (Figure S7). For example, the
relative intensity ratio between the Q band and Soret band
(IQ/ISoret) was 0.64 for the CuP monomer, which increased to
0.98 for the CuP-2,3-DHPh COF. These results indicate that
the construction of 2D COFs with stacked porphyrin structures
enhanced their absorption capabilities.
In summary, we have succeeded in the designed synthesis
of a series of two-dimensional porphyrin COFs with different
porphyrin species and edge units. The porphyrin units were
covalently integrated into the 2D polymer sheets that were
further stacked to constitute layered frameworks. Consequently,
the porphyrin units are located at the vertices of extended
tetragonal polygons, giving rise to periodically ordered colum-
nar porphyrin π-arrays. Such extended porphyrin arrays are not
achieved through other covalent and/or noncovalent approaches.
Tuning the size and geometry of the edge units allows the
porphyrin frameworks to be tailored to possess tetragonal or
rhombic polygons with pore sizes ranging from micropores to
mesopores. The frameworks are highly porous, exhibit extended
π-conjugation, and show improved light absorption capability.
We envisage that the extended porphyrin frameworks will create
new opportunities in the chemistry of porphyrins and related
macrocycles by offering unique structures that can be elabo-
rately designed and can be synthesized in a straightforward
manner via polycondensation.
Supporting Information is available electronically on J-STAGE.
References
Figure 3. Nitrogen sorption isotherm curves for (a) MP-PyTTPh
COFs (black: ZnP-PyTTPh COF; red: CuP-PyTTPh COF; blue: NiP-
PyTTPh COF), (b) MP-2,3-DHPh COFs (black: ZnP-2,3-DHPh COF;
red: CuP-2,3-DHPh COF; blue: NiP-2,3-DHPh COF), (c) CuP-
DHNAPh COF, and (d) CuP-BPyPh COF, measured at 77 K (solid
circles are adsorption and open circles are desorption). (e) The BET
surface areas of the COFs.
1
2
A. P. Côté, A. I. Benin, N. W. Ockwig, M. O’Keeffe, A. J.
M. G. Rabbani, A. K. Sekizkardes, Z. Kahveci, T. E. Reich, R.
S.-Y. Ding, J. Gao, Q. Wang, Y. Zhang, W.-G. Song, C.-Y. Su,
A. Nagai, X. Chen, X. Feng, X. Ding, Z. Guo, D. Jiang, Angew.
X. Chen, M. Addicoat, E. Jin, L. Zhai, H. Xu, N. Huang, Z. Guo,
H. Xu, X. Chen, J. Gao, J. Lin, M. Addicoat, S. Irle, D. Jiang,
3
4
5
6
7
8
9
conducted at 77 K (Figures 3a-3d). The Brunauer-Emmett-
Teller (BET) surface areas were 1127, 1070, 1026, 1099, 854,
¹1
1064, 1656, and 883 m2 g for the CuP-PyTTPh COF, NiP-
PyTTPh COF, ZnP-PyTTPh COF, CuP-2,3-DHPh COF, NiP-
2,3-DHPh COF, ZnP-2,3-DHPh COF, CuP-DHNAPh COF, and
the CuP-BPyPh COF, respectively (Figure 3e and Table S5).
The pore volumes were 0.82, 0.76, 0.75, 0.78, 0.60, 0.77, 1.38,
¹1
and 0.64 cm3 g for CuP-PyTTPh COF, NiP-PyTTPh COF,
ZnP-PyTTPh COF, CuP-2,3-DHPh COF, NiP-2,3-DHPh COF,
ZnP-2,3-DHPh COF, CuP-DHNAPh COF, and CuP-BPyPh
COF, respectively (Table S5). One significant feature is that
the porphyrin-based COF contains only one type of pore, as
revealed by the pore size distribution profiles (Figure S6).
The imine-linkage COFs enable the π-conjugation to be
extended over the 2D polyporphyrin layers, as indicated by their
red-shifted Soret bands compared to those of their monomers
(Figure S7). CuP-PyTTPh COF, NiP-PyTTPh COF, ZnP-
PyTTPh COF, CuP-2,3-DHPh COF, NiP-2,3-DHPh COF, ZnP-
2,3-DHPh COF, CuP-DHNAPh COF, and CuP-BPyPh COF
exhibited broad Soret bands centered at 451, 449, 459, 479, 452,
476, 456, and 455 nm, respectively, which were red-shifted by 9,
3, 5, 37, 6, 22, 14, and 13 nm compared to the Soret bands of
their porphyrin monomers, respectively. Notably, the absorban-
10 J. Guo, Y. Xu, S. Jin, L. Chen, T. Kaji, Y. Honsho, M. A.
Addicoat, J. Kim, A. Saeki, H. Ihee, S. Seki, S. Irle, M.
11 C. R. DeBlase, K. E. Silberstein, T.-T. Truong, H. D. Abruña,
12 F. Xu, S. Jin, H. Zhong, D. Wu, X. Yang, X. Chen, H. Wei, R.
13 S. Wan, F. Gándara, A. Asano, H. Furukawa, A. Saeki, S. K.
Dey, L. Liao, M. W. Ambrogio, Y. Y. Botros, X. Duan, S. Seki,
14 X. Feng, L. Liu, Y. Honsho, A. Saeki, S. Seki, S. Irle, Y. Dong,
© 2015 The Chemical Society of Japan | 1259