10.1002/anie.201909851
Angewandte Chemie International Edition
RESEARCH ARTICLE
7-cm long column; THF) to separate the mixtures by their polarity
difference in THF and observed that they cannot be separated
(Figure S15). Thus, the recognition and separation as well as
transportation by the 1D channels are not based on polarity but
driven solely by a subtle difference of molecular size.
Conclusion
In summary, we have established a strategy for size
recognition of synthetic 1D nanochannels, by exploring a latticed
framework with shape-persistent triangular pores. One important
knowledge we disclosed through this study is that the 2D π
surface of the framework, the triangular aperture and the pore
walls with built-in C–H sequences are key structural parameters
in size recognition. Their cooperativeness renders the COF able
to combine precise size recognition of one atom difference,
selective docking and transport and instant separation in one
material, demonstrating the strength of 1D channels for accurate
molecular recognition and separation – an ultimate goal of porous
materials in implementation. These unique properties of synthetic
1D channels are established for the first time in COFs and would
exert great impact on the further advance of the field. We
envisage that synthetic 1D channels could offer a promising
platform for designing robust size recognition devices that are
useful in adsorption, transportation and separation.
Acknowledgements
Figure 5 a) Electronic absorption spectral change of the THF solution of a
D.J. acknowledges MOE tier 1 grant (R-143-000-A71-114). M.A.
acknowledges support from EPSRC, EP/S015868/1 and HPC
resources on T.H. via the Materials Chemistry Consortium,
EP/P020194. T.H. acknowledges financial support via Deutsche
Forschungsgemeinschaft, SPP 1928 COORNETs, under contract
number HE 3543/30-1.
mixture of NR/DAPC (1/1 molar ratio), upon addition of HTP-BDA-COF (black
curve, pristine; blue curve, after 30 s; red curve, after 2 min). b) Time-dependent
retentivity of NR (red circles and curve) and DAPC (black circles and curve) in
solution. NR is sorted into the channels and DAPC is retained in solution. c)
Electronic absorption spectral change of the THF solution of a mixture of NR/C6
(1/1 molar ratio), upon addition of HTP-BDA-COF (black curve, pristine; blue
curve, after 30 s; red curve, after 2 min). d) Time-dependent retentivity of NR
(red circles and curve) and C6 (black circles and curve) in solution. NR is sorted
into the channels and C6 is retained in solution. e) The COF column flow-out
charts of C6 (black curve), NR (red curve), and C6 plus NR (blue curve) for a
mixture of NR/C6 at 1/1 molar ratio at ambient temperature and pressure. f) The
COF column flow-out charts of DAPC (black curve), NR (red curve), and DAPC
plus NR (blue curve) for a mixture of NR/DAPC at 1/1 molar ratio at ambient
temperature and pressure.
Keywords: covalent organic framework• size recognition •
separation • 1D nanochannels • trigonal topology
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