2 research outputs found
A Pyrene-Based, Fluorescent Three-Dimensional Covalent Organic Framework
The targeted synthesis of 3D COFs
has been considered challenging,
especially adopting new topologies and bearing photoelectric units.
Herein, for the first time, we report the synthesis and characterization
of a novel 3D pyrene-based COF (3D-Py-COF), by selectively choosing
the geometry of the precursors and the connection patterns. Based
on X-ray diffraction measurement and detailed simulations, 3D-Py-COF
is proposed to adopt a two-fold interpenetrated <b>pts</b> topology,
which has never been reported before. In addition, 3D-Py-COF has a
narrow pore size distribution and high surface area and also features
selective absorption of CO<sub>2</sub> over N<sub>2</sub>. Interestingly,
due to the existence of isolated pyrene units in the 3D framework,
3D-Py-COF is the first fluorescent 3D COF and can be used in explosive
detection. Our results not only show it is possible to rationally
design and synthesize 3D COFs with other topologies but also demonstrate
that the incorporation of photoelectric units into 3D COFs can allow
the resulting materials with interesting properties
3D Porphyrin-Based Covalent Organic Frameworks
The design and synthesis
of three-dimensional covalent organic
frameworks (3D COFs) bearing photoelectric units have been considered
as a big challenge. Herein, for the first time, we reported the targeted
synthesis of two 3D porphyrin-based COFs (3D-Por-COF and 3D-CuPor-COF),
starting from tetrahedral (3D-<i>T</i><sub>d</sub>) and
square (2D-<i>C</i><sub>4</sub>) building blocks connected
through [4 + 4] imine condensation reactions. On the basis of structural
characterizations, 3D-Por-COF and 3D-CuPor-COF are microporous materials
with high surface areas, and are proposed to adopt a 2-fold interpenetrated <b>pts</b> topology with <i>Pmc</i>2<sub>1</sub> space
group. Interestingly, both 3D COFs are photosensitive and can be used
as heterogeneous catalyst for generating singlet oxygen under photoirradiation.
However, 3D-Por-COF shows enhanced photocatalytic activity compared
with 3D-CuPor-COF, indicating the properties of 3D porphyrin-based
COFs can be tuned by metalation of porphyrin rings. The results reported
here will greatly inspire us to design and synthesize 3D COFs bearing
other metalloporphyrins for interesting applications (e.g., catalysis)
in the future