Construction of a Hierarchical Architecture of Covalent Organic

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Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Post-Synthetic Approach Gen Zhang, Masahiko Tsujimoto, Daniel Packwood, Nghia Duong, Yusuke Nishiyama, Kentaro Kadota, Susumu Kitagawa, and Satoshi Horike J. Am. Chem. Soc., Just Accepted Manuscript • DOI: 10.1021/jacs.7b12350 • Publication Date (Web): 27 Jan 2018 Downloaded from http://pubs.acs.org on January 27, 2018

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Journal of the American Chemical Society

Construction of a Hierarchical Architecture of Covalent Organic Frameworks via a Post-Synthetic Approach Gen Zhang,† Masahiko Tsujimoto,† Daniel Packwood,† Nghia Tuan Duong,‡ Yusuke Nishiyama,‡,¶ Kentaro Kadota,|| Susumu Kitagawa,*† and Satoshi Horike*,†,§, # †

Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Institute for Advanced Study, and §AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL), Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan ‡ RIKEN CLST-JEOL Collaboration Center, Tsurumi, Yokohama, Kanagawa 230-0045, Japan ¶

JEOL RESONANCE Inc., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan

||

Department of Molecular Engineering, and #Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan Supporting Information ABSTRACT: Covalent organic frameworks (COFs) represent an emerging class of crystalline porous materials that are constructed by the assembly of organic building blocks linked via covalent bonds. Several strategies have been developed for the construction of new COF structures; however, a facile approach to fabricate hierarchical COF architectures with controlled domain structures remains a significant challenge, and has not yet been achieved. In this study, a dynamic covalent chemistry (DCC)-based post-synthetic approach was employed at the solid–liquid interface to construct such structures. Two-dimensional imine-bonded COFs having different aromatic groups were prepared, and a homogeneously mixed-linker structure and a heterogeneously coreshell hollow structure was fabricated by controlling the reactivity of the post-synthetic reactions. Solid-state nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) confirmed the structures. COFs prepared by postsynthetic approach exhibit several functional advantages compared with their parent phases. Their Brunauer–Emmett–Teller (BET) surface areas are two-fold greater than those of their parent phases because of the higher crystallinity. In addition, the hydrophilicity of the material and the stepwise adsorption isotherms of H2O vapor in the hierarchical frameworks were precisely controlled, which was feasible because of the distribution of various domains of the two COFs by controlling the post-synthetic reaction. The approach opens new routes for constructing COF architectures with functionalities that are not possible in a single phase.

INTRODUCTION Fabrication of hierarchical materials containing multiscale structures such as core–shell, hollow, and lamellar structures1-2 is a typical and powerful approach to create new functionalities that cannot be represented by single-phase materials. 3-4 In addition, porous solids such as zeolites and metal–organic frameworks (MOFs) have been investigated for the formation of various hierarchical structures.5-6 Covalent organic frameworks (COFs) are an emerging class of crystalline porous materials and are constructed by linking organic building units via covalent bonds.7-8 They exhibit large potential applications in many fields. Over the last decade, considerable efforts have been devoted to the construction of new COF structures, including chiral, ionic, and guest-responsive (dynamic) structures.8-9 Several studies have also reported the morphology control of single-phase COFs such as films and fibers.10 In addition to the significance of structural design to construct new frameworks, domain control of the structure and construction of hierarchical structures in COFs are crucial but are unexplored. Therefore, the development of synthetic and/or analytic approaches for domain control and hierarchical structuring of COFs are considerable challenges to expand the

chemistry and material in this field, which can open avenues for the synthesis of new materials with novel properties. In this study, a strategy to prepare hierarchical structures for an imine-linked COF system by a post-synthetic approach11 is proposed. Imine-linked COFs are formed by the condensation of aldehydes and amines. The COF formation follows the principle of dynamic covalent chemistry (DCC) where the reversible covalent bond formation and breaking under thermodynamic control.12 The dynamic nature of DCC at the solid–liquid interface is exploited for the construction of multidomain or core-shell COF architectures. Solid-state nuclear magnetic resonance (NMR) spectroscopy and high-resolution transmission electron microscopy (TEM) were employed for structural characterization. The COF structures prepared from two parent-phase COFs via DCC-induced post synthesis exhibited the distribution of various domains and hierarchical structures with sufficient thermal and chemical stabilities. On account of this unique functionality, the systematic control of hydrophilicity in COFs was demonstrated to fine tune the H2O vapor uptake behavior.

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Scheme 1. Syntheses of COF-Ph, COF-Naph, COF-Ph-Naph, and COF-Naph-Ph by a post-synthetic process, and representation of their morphologies according to the results obtained from TEM and solid-state NMR spectroscopy measurements.

Figure 1. (a) PXRD patterns of COF-Ph (i) and COF-Ph-Naph (ii–iv). (b) PXRD patterns of COF-Naph (i) and COF-Naph-Ph (ii–iv) (c) FT-IR spectra and (d) 1H NMR spectra of HCl-degraded solutions of COF-Ph (i), COF-Ph-Naph (ii), COF-Naph (iii), and COF-NaphPh (iv).

RESULTS AND DISCUSSION Two imine-linked COFs were prepared by the condensation of benzene-1,3,5-tricarbaldehyde and 1,4-diaminobenzene or 1,4-diaminonaphthalene under solvothermal conditions (Scheme 1). Hereafter, each of the products is referred to as COF-Ph (also named as COF-LZU-1)9b and COF-Naph. Chemical formulas of COF-Ph and COF-Naph are (C6H4N)n and (C8H5N)n, respectively. COF-Ph and COF-Naph obtained

as yellow solids were not soluble in any common organic solvent. Powder X-ray diffraction (PXRD) of COF-Ph and COFNaph were measured (Figure 1). The PXRD pattern of COFPh was the same as that reported previously.9b In addition, a strong peak was observed at 4.74° with a d-spacing of 18.64 Å, corresponding to the 100 diffraction, with some weak peaks at 8.44°, 9.64°, 12.24°, and 26.42°, corresponding to the 110, 200, 210, and 001 diffractions, respectively (Figure 1a, i). The observed PXRD pattern of COF-Naph was similar to that of


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Journal of the American Chemical Society COF-Ph because of the same size of the amine linker. An intense peak was observed at 4.76°, with a d-spacing of 18.57 Å, corresponding to the 100 diffraction, with some weak peaks at 9.64°, 12.24°, and 26.42°, corresponding to the 200, 210, and 001 diffractions, respectively (Figure 1b, i). The simulated PXRD pattern of COF-Naph with a hexagonal unit cell and an eclipsed stacking structure calculated by the Materials Studio software was in good agreement with the experimental data (Figure S2–S3 and Table S1). The vibration bands observed at 1620 cm−1 in the Fourier transform infrared (FT-IR) spectrum corresponded to the -C=N- stretching vibration, revealing the successful formation of imine bonds in both frameworks (Figure 1c, i and iii). COF-Ph exhibited a strong -C=C- stretching vibration at 1520 cm−1, corresponding to the benzene ring derived from 1,4-diaminobenzene, whereas this vibration band was not observed for COF-Naph. Solid-state 13C NMR spectra of COF-Ph and COF-Naph were recorded to observe distinct differences in both frameworks (Figure 2a). Figure 2a also shows the peak assignment. Several differences were observed for peaks at 113 ppm and in the 140–150 ppm region, which aids in the discussion of the hierarchical structure of COF later. Although overlapped peaks were observed at 131 ppm for both COFs, a significantly stronger peak intensity for COF-Naph helps to understand its structure. The observed spectrum for COF-Ph was the same as that reported previously.9b TEM measurements revealed a hollow structure for COF-Ph particles (Figure 3a), whereas particles with a dense spherical morphology were observed for COF-Naph (Figure 3c). A clear hexagonal lattice structure was observed for both compounds (Figure 3b and 3d), confirming the formation of ordered columnar channels in the structures.10a, 10c TEM images at the center of COF-Ph particles show the hexagonal pattern representing the projection of 1D channels along the c-axis, and at the edge of COF-Naph show atomic rows parallel to the c-axis in the rods (Figure 3 and S30). TEM and STEM-HAADF (scanning transmission electron microscopy–high angle annular dark field) images for both COFs and COF-Naph isolated from different reaction time show clear growth of rod-shape crystallites parallel to the radial orientation of spheres (Figure S31-S33). These results suggest both COF-Ph and COF-Naph particles are composed by the rod-shape microcrystals which are parallel to the radial orientation of spheres. As observed from the TEM measurements, the d-spacing values of COF-Ph and COF-Naph were 1.75 and 1.63 nm (Figure S26), respectively; these values are slightly shorter than those obtained from PXRD. The same observation was reported previously.9f

Figure 2. Solid-state 13C NMR spectra of (a) COF-Ph and COF-Naph with peak assignments for (b) COF-Ph and COF-PhNaph (c) COF-Naph and COF-Naph-Ph.

Nitrogen gas (N2) sorption experiments were performed at 77 K for COF-Ph and COF-Naph (Figure 4a and 4b, respectively). Sorption isotherms of the two COFs exhibited a Type-I profile, indicative of a microporous structure. The calculated Brunauer–Emmett–Teller (BET) surface areas were 736 m2 g−1 for COF-Ph and 464 m2 g−1 for COF-Naph. The observed surface areas of COF-Ph was 80% higher than that reported one (410 m2 g−1, Figure S7).9b The optimized synthetic conditions can help in the preparation of high crystallinity imine-linked COFs (Table S2 and Figures S4–S5). The theoretical maximum BET surface areas13 of COF-Ph and COF-Naph calculated by Material Studio14 are 2151 m2 g−1 and 1074 m2 g−1, respectively (Equation S1). The pore size distribution of COFPh and COF-Naph calculated by nonlocal density functional theory (NLDFT) revealed a narrow distribution of pore widths at 1.79 and 1.63 nm (Figures S21 and S23, respectively). The values correspond to those obtained from TEM.



tion bands corresponding to the non-reacted aldehyde at 1700 cm−1 in the FT-IR spectrum decreased as a result of the reaction with 1,4-diaminonaphthalene (Figure S10).

Figure 3. TEM images of (a, b) COF-Ph (c, d) COF-Naph (e, f) COF-Ph63-Naph37 (g, h), and COF-Naph80-Ph20.

The integration of COF-Ph and COF-Naph structures in a single particle via a DCC-induced post-synthetic approach was attempted. A solid–liquid reaction for COF-Ph and 1,4diaminonaphthalene via post-synthetic imine exchange (Scheme 1, top) was conducted using 1, 2, and 4 equivalents of 1,4-diaminonaphthalene to the benzene ring derived from 1,4-diaminobenzene in COF-Ph. After the reaction was performed at 70°C for 96 h, the powder products were filtered and washed with tetrahydrofuran. Hereafter, the products were referred to as COF-Ph-Naph. Figure 1a, ii–iv shows the PXRD patterns of the three COF-Ph-Naph products. With the increase in the amount of 1,4-diaminonaphthalene, the intensity of the peak at 8.44° with the 110 diffraction gradually decreased. In addition, the intensity of the peak observed at 9.64° with the 200 diffraction gradually increased, suggesting that a part of the 1,4-diaminobenzene of COF-Ph is replaced by 1,4diaminonaphthalene via post-synthetic exchange. The intensities of the main peak at 4.76° in the PXRD patterns of COFPh-Naph (1, 2, and 4 equivalents) were stronger than those of COF-Ph (Figure 1a, i). The post-synthetic exchange process improves the framework crystallinity. As evidences, the vibra-

Figure 4. Adsorption isotherms of N2 at 77 K for (a) COF-Ph and the three products of COF-Ph-Naph (b) COF-Naph and three products of COF-Naph-Ph (c) the amount of the exchanged moiety in COF-Ph–Naph (blue) and COF-Naph-Ph (red) as a function of the amount from the exchange reaction.

To further confirm whether COF-Ph-Naph comprise the original benzene ring and exchanged naphthalene ring, the COF-Ph-Naph powder was hydrolyzed using concentrated HCl and examined by liquid 1H NMR spectroscopy (Figures 1d, ii and S13). The 1H NMR spectra of COF-Ph and COFNaph were also measured by the same procedure for comparison. In the 1H NMR spectrum of hydrolyzed COF-Ph-Naph, peaks corresponding to 1,4-diaminobenzene and 1,4diaminonaphthalene were observed. The proportion of the benzene and naphthalene rings in COF-Ph-Naph were 63:37, 42:58, and 27:73, corresponding to the reactions with 1, 2, and 4 equivalents (Figures 4c and S13). Their noted names are COF-Ph63-Naph37, COF-Ph42-Naph58, and COF-Ph27-Naph73, respectively. To investigate the morphology of COF-Ph-Naph, we selected COF-Ph63-Naph37 and measured TEM (Figure 3e).


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Journal of the American Chemical Society Uniform hollow spheres identical to COF-Ph were observed. The STEM-HAADF measurements revealed a spherical hollow structure for COF-Ph and COF-Ph-Naph with the shell thickness of 70-100 nm (Figure S32). This suggests the gradual replacement of 1,4-diaminobenzene with 1,4diaminonaphthalene in COF-Ph with the retention of the original particle morphology. Thus, the moieties of 1,4diaminobenzene and 1,4-diaminonaphthalene are assumed to be homogeneously mixed in COF-Ph-Naph (Scheme 1). To clarify the homogeneous-mixed structure of COF-Ph-Naph, a solid-state 13C NMR spectrum of COF-Ph63-Naph37 was recorded (Figure 2b). Peaks at 113 and 146 ppm for COF-Naph were not observed for COF-Ph63-Naph37, indicating that a large domain or identical particle of COF-Naph is not formed in COF-Ph63-Naph37. The naphthalene rings in COF-Ph63Naph37 are confirmed by a strong peak at 131 ppm. The results obtained from solid-state NMR spectroscopy, liquid 1H NMR spectroscopy, PXRD, and TEM indicated that COF-Ph-Naph has a single-phase structure with the homogeneous distribution of benzene and naphthalene rings in the structure, as shown in Scheme 1. N2 sorption isotherms of COF-Ph-Naph at 77 K showed a Type-I profile (Figure 4a). The calculated BET surface areas of COF-Ph63-Naph37, COF-Ph42-Naph58, and COF-Ph27-Naph73 were 1033, 1405, and 1197 m2 g−1, respectively; these values are considerably higher than that of COF-Ph (736 m2 g−1) although their molecular weights are larger than that of COF-Ph. The pore size distribution of all COF-Ph-Naph products was 1.67 nm (Figure S21). The higher surface area was related to the higher crystallinity of compounds, and the comparable amounts of 1,4-diaminobenzene and 1,4-diaminonaphthalene moieties in COF-Ph42-Naph58 rendered the highest crystallinity and BET surface area presumably because of negligible defects and structural stabilization. The control experiments show that the post synthesis reaction for studied COFs by their original diamine could improve the crystallinity and BET surface area, but an excess of the original ligand employed for COF construction provides low crystalline compound (Figure S27 and S28). By utilizing post-synthetic exchange, COF-Naph-Ph was also prepared from COF-Naph with 1,4-diaminobenzene under solid–liquid suspension conditions using 1, 2, and 4 equivalents of the 1,4-diaminobenzene to the naphthalene ring derived from 1,4-diaminonaphthalene in COF-Naph. The PXRD patterns of the three COF-Naph-Ph products showed a peak at 8.44° (Figure 1b, ii–iv), corresponding to the 110 diffraction; this diffraction was only observed for COF-Ph. COF-Naph-Ph exhibited a new strong vibration band at 1520 cm−1 in the FTIR spectrum (Figures 1c, iii–iv, and S11), corresponding to the -C=C- stretching vibration of 1,4-diaminobenzene. With the increase in the amount of 1,4-diaminobenzene, the band intensity increased (Figure S11). The amounts of 1,4diaminonaphthalene and 1,4-diaminobenzene moieties in COF-Naph-Ph were examined by 1H NMR by degradation with concentrated HCl (Figures 1d, iii–iv, and S14). Their ratios in COF-Naph-Ph were 80:20 (COF-Naph80-Ph20), 74:26 (COF-Naph74-Ph26), and 64:36 (COF-Naph64-Ph36). The amount of the exchanged 1,4-diaminobenzene moiety in COFNaph-Ph was less than that in COF-Ph-Naph (Figure 4c) because of the slow post-synthetic exchange process in COFNaph, which comprised strong interlayer π–π stacking.

Careful observation from TEM revealed that rod-shaped small crystals (~10 nm) were embedded on the hollow spheres (Figure 3g). The morphology was different from that of COFNaph, which exhibited dense aggregation (Figure 3c). STEMHAADF images of COF-Naph80-Ph20 indicates the structure is spherical hollow and the thickness about 180 nm (Figure S33). The formation of hollow COF-Naph-Ph from dense COFNaph is through the partial dissolution of the particle15 and recrystallization with 1,4-diaminobenzene, affording crystals of COF-Ph on the surface of the hollow structure.16 To clarify the partial dissolution process, we tried reactions with COFNaph and variety concentrations of 1,4-diaminobenzene solutions. As the concentration increases, the yield of COF-NaphPh decreases, and we did not obtain any powder of COFNaph-Ph when 12 equivalents amount of 1,4-diaminobenzene to the naphthalene ring derived from 1,4-diaminonaphthalene in COF-Naph was employed (Figure S1). This suggests that the formation of COF-Naph-Ph is accompanied with the partial dissolution of COF-Naph. Since the core-shell structure of COF-Naph-Ph is suggested, the structure of COF-Naph80-Ph20 was characterized by solid-state 13C NMR spectroscopy (Figure 2c). The unique peaks attributed to 1,4-diaminobenzene in COF-Ph at 148 ppm and 1,4-diaminonaphthalene in COFNaph at 146 and 113 ppm were observed in COF-Naph80-Ph20. 15 N CP/MAS NMR spectra of COF-Naph, COF-Naph-Ph-15N, and COF-Ph-15N show that COF-Naph does not apparently observe the peak because of low sensitivity, and COF-Ph-15N has a single 15N signal at 53 ppm (Figure S15). The same peak is also observed in the COF-Naph-Ph-15N indicating COFNaph-Ph contains COF-Ph domain in the structure. By considering that uniform particles with a hollow structure were observed in the TEM image of COF-Naph80-Ph20, each particle comprised two domains of COF-Ph and COF-Naph. The results obtained from solid-state NMR spectroscopy, liquid 1H NMR spectroscopy, PXRD, and TEM suggested that COFNaph-Ph comprises a core-shell structure with COF-Ph on the hollow COF-Naph particles. N2 sorption isotherms of the three COF-Naph-Ph products at 77 K showed a Type-I profile, which is characteristic of a microporous structure for both COF-Ph and COF-Naph domains (Figure 4b). The BET surface areas of COF-Naph80-Ph20, COF-Naph74-Ph26, and COF-Naph64-Ph36 were 729, 863, and 1113 m2 g−1, respectively; these values are greater than the BET areas of COF-Naph (464 m2 g−1). The pore size distribution profiles revealed that COFs exhibit micropores (1.67 nm) similar to those observed in COF-Naph (Figure S23). Similar to the case of post-synthesis of COF-Ph-Naph, the postexchange process improves the crystallinity of the structure and results in higher BET surface area.



Figure 5. Adsorption isotherms of H2O vapor at 298 K for (a) COF-Ph and COF-Naph (b) solid mixture of COF-Naph (74 wt%) and COF-Ph (26 wt%). (c) Three products of COF-Ph-Naph (d) three products of COF-Naph-Ph. (e) Pa as a function of the ratio of the 1,4diaminonaphthalene moiety in COF-Ph-Naph. (f) Amount of water sorption (25 °C, P/P0 = 0.95) for zeolite 13X, MOF-801, UiO-66, MOF-841, Mg-MOF-74, Basolite A300 and MCM-41 by comparing with COF-Ph42-Naph58.

The development of porous solids for the adsorption/desorption of water (H2O) vapor is crucial because such solids can be applied further for water purification and delivery, dehumidification, and adsorption-based thermal batteries.17 Compared with other porous materials such as zeolites, mesoporous silica, activated carbon, and MOF,18 only a few COFs have been examined for H2O adsorption to the best of our knowledge, and the control of their sorption isotherms has not been achieved.19 The tuning of the hydrophilicity of porous solids is crucial for the above-mentioned applications. Hence, the tunability of the H2O sorption behavior for COFs prepared from COF-Ph and COF-Naph was investigated. Figure 5a shows the H2O adsorption and desorption curves of COF-Ph and COF-Naph at 25 °C: Sigmoidal isotherms with hysteresis loops were observed. COF-Naph was less hydrophilic because

of an electron rich naphthalene ring in the pore wall. Hereafter, the relative adsorption pressure (Pa) at the inflection point of the sigmoidal adsorption isotherm will be used and discussed. Pa corresponded to the condensation of water molecules in the pores and served as an index of hydrophilicity. For COF-Ph, Pa = 0.39 with a total uptake of 489 cm3 g−1 at P/P0 = 0.95 (39 wt%). For COF-Naph, Pa = 0.67 with a total uptake of 362 cm3 g−1 at P/P0 = 0.95 (29 wt%). PXRD of COF-Ph and COF-Naph after H2O adsorption are unchanged (Figure S24). The three COF-Ph-Naph products also exhibited sigmoidal isotherms (Figure 5c) with the total uptake amounts greater than those of COF-Ph and COF-Naph because of the higher surface area. The highest total uptake was 940 cm3 g−1 (75 wt%) for COF-Ph42-Naph58 at P/P0 = 0.95. This value is greater than that of zeolite 13X (412 cm3 g−1), MOF-801 (446 cm3


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Journal of the American Chemical Society g−1), UiO-66 (532 cm3 g−1), MOF-841 (618 cm3 g−1), MgMOF-74 (750 cm3 g−1), Basolite A300 (815 cm3 g−1) and MCM-41 (960 cm3 g−1) under the same conditions (Figure 5f).20 Notably, with the increase in the ratio of the 1,4diaminonaphthalene moiety in COF-Ph-Naph, Pa linearly shifted to a high-pressure region (Figure 5e), indicating that the hydrophilicity is tuned by the modification of the composition of 1,4-diaminobenzene and 1,4-diaminonaphthalene in COF-Ph-Naph. For comparison, the mixed-linker COF was also synthesized from one-pot reactions of 1,4diaminobenzene and 1,4-diaminonaphthalene (denoted as COF-ML).21 The H2O adsorption isotherms of COF-ML exhibited a sigmoidal isotherm similar to that of COF-Ph-Naph but with lower uptake capacity (Figure S24). For example, the Pa of COF-ML2 (1,4-diaminobenzene: 1,4diaminonaphthalene = 48:52) was 0.52; this value is comparable to that of COF-Ph42-Naph58, (Pa = 0.53), but the uptake amount of H2O at P/P0 = 0.95 is 23% less than that of COFPh42-Naph58 because of its low crystallinity as a result of the one-pot reaction.

ble-domain core-shell hollow structure is in accordance with the partial dissolution-recrystallization mechanism, and the study herein suggested that an active solid interface of iminebonded COFs is useful to fabricate various hierarchical architectures. Post-synthesized COFs exhibit several functional advantages compared with their parent phases. The BET surface areas of the optimized mixed-linker COFs were two-fold greater than those of their parent phases on account of the improvement of crystallinity via the post-linker exchange process. In addition, the systematic control of hydrophilicity of the materials and the stepwise adsorption isotherms of H2O vapor in the core-shell frameworks are demonstrated. Hierarchical structures with a high crystallinity of COFs via postsynthesis provide the design of new materials and according functionalities, which open new avenues of research into COFs.

In contrast, the three products of COF-Naph-Ph exhibited two-step adsorption isotherms for H2O (Figure 5d). COFNaph80-Ph20 exhibited two Pa values of 0.50 and 0.67, respectively, to achieve an uptake of 558 cm3 g−1 (45 wt%) at P/P0 = 0.95. The first Pa value was higher than that of COF-Ph (Pa = 0.39), whereas the second Pa value was the same as that of COF-Naph (Pa = 0.67). The stepwise uptake is related to the core-shell structures of COF-Naph-Ph containing of COF-Ph and COF-Naph domain structures. With the increase in the amount of COF-Ph, the three COF-Naph-Ph products exhibited a gradual shift of Pa to the low-pressure region, and the total amount of uptake increased with COF-Ph amount increase. The lower shift of Pa is due to the increased hydrophilicity of COF-Naph-Ph, and the higher uptake amount corresponded to the improvement of crystallinity in addition to the lower molecular weight (Figure S25). Notably, Pa in the first step for all the three products of COF-Naph-Ph was higher than that of COF-Ph, although the first Pa was observed for the crystals of COF-Ph on the surface of COF-Naph-Ph. This is probably because the domain of COF-Ph on COF-Naph-Ph comprised some of the 1,4-diaminonaphthalene moieties. To investigate the advantages of COF-Naph-Ph for H2O sorption versus the physical powder mixture of COF-Ph and COFNaph, a powder mixture of COF-Naph (74 wt%) and COF-Ph (26 wt%) was prepared, and H2O sorption isotherms were recorded (Figure 5b). The mixture sample showed a total uptake of 396 cm3 g-1 at P/P0 = 0.95, which is the simple sum of 74 wt% of COF-Naph (268 cm3 g−1) and 26 wt% COF-Ph (127 cm3 g−1). The total uptake of simple mixture sample is 37% lower than COF-Naph74-Ph26 (632 cm3 g−1). The study for H2O adsorption for both the structures of COF-Ph-Naph and COFNaph-Ph revealed their advantages with regard to the tuning of isotherms (or hydrophilicity) with enhanced surface area.

Experimental details and additional characterizations (PXRD, TG/DTA, FT−IR, 1H NMR, solid state NMR, N2 and H2O adsorption, TEM, SEM). This material is available free of charge via the Internet at http://pubs.acs.org.

CONCLUSION A DCC-induced post-synthetic reaction for imine-bonded COFs at the solid–liquid interface is a powerful approach for creating structures with various compositions and for creating hierarchical structures. By controlling the reactivity of the reactants during post-synthesis, a mixed-linker structure and core-shell hollow structure were fabricated, some of which are not accessible by conventional routes. The growth of the dou-

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AUTHOR INFORMATION Corresponding Author *[email protected] *[email protected]

Author Contributions The manuscript was written through contributions of all authors.

ACKNOWLEDGMENT This work was supported by Advanced Program for Program Manager’s Candidate Hub (APPROACH), and “Molecular Technology” of Strategic International Collaborative Research Program (SICORP) from the Japan Science and Technology Agency (JST) and KAKENHI Grant-in-Aid for Specially Promoted Research (No. 25000007) from the Japan Society of the Promotion of Science (JSPS). WPI-iCeMS is supported by World Premier International Research Initiative (WPI), MEXT, Japan. G. Z. thanks to JSPS Postdoctoral Fellowships for Research in Japan.

REFERENCES (1) (a) Lakes, R. Nature 1993, 361, 511-515. (b) Katz, E.; Willner, I. Angew. Chem., Int. Ed. 2004, 43, 6042-6108. (c) Mei, J.; Diao, Y.; Appleton, A. L.; Fang, L.; Bao, Z. J. Am. Chem. Soc. 2013, 135, 6724-6746. (d) Zhan, G.; Zeng, H. C. Coordin. Chem. Rev. 2016, 320321, 181-192. (e) Stassen, I.; Burtch, N.; Talin, A.; Falcaro, P.; Allendorf, M.; Ameloot, R. Chem. Soc. Rev. 2017, 46, 3185-3241. (2) (a) Li, G. L.; Mohwald, H.; Shchukin, D. G. Chem. Soc. Rev. 2013, 42, 3628-3646. (b) Seoane, B.; Coronas, J.; Gascon, I.; Etxeberria Benavides, M.; Karvan, O.; Caro, J.; Kapteijn, F.; Gascon, J. Chem. Soc. Rev. 2015, 44, 2421-2454. (c) Nejad, M. N.; Asghari, M.; Afsari, M. ChemBioEng. Rev. 2016, 3, 276-298. (3) (a) Turkiewicz, A.; Paley, D. W.; Besara, T.; Elbaz, G.; Pinkard, A.; Siegrist, T.; Roy, X. J. Am. Chem. Soc. 2014, 136, 15873-15876. (b) Wang, H.; Zhuo, S.; Liang, Y.; Han, X.; Zhang, B. Angew. Chem., Int. Ed. 2016, 55, 9055-9059. (4) (a) Yao, H. B.; Fang, H. Y.; Wang, X. H.; Yu, S. H. Chem. Soc. Rev. 2011, 40, 3764-3785. (b) Mo, Q.; Wei, J.; Jiang, K.; Zhuang, Z.; Yu, Y. Acs. Sustain. Chem. Eng. 2016, 5, 1476-1484. (5) (a) Dong, Q.; Su, H.; Song, F.; Zhang, D.; Wang, N. J. Am.



Chem. Soc. 2007, 90, 376-380. (b) Hu, J.-S.; Zhong, L.-S.; Song, W.G.; Wan, L.-J. Adv. Mater. 2008, 20, 2977-2982. (c) Singh, S.; Lo, S.L. Chem. Eng. J. 2017, 309, 753-765. (6) (a) Furukawa, S.; Hirai, K.; Nakagawa, K.; Takashima, Y.; Matsuda, R.; Tsuruoka, T.; Kondo, M.; Haruki, R.; Tanaka, D.; Sakamoto, H.; Shimomura, S.; Sakata, O.; Kitagawa, S. Angew. Chem., Int. Ed. 2009, 48, 1766-1770. (b) Yue, Y.; Fulvio, P. F.; Dai, S. Acc. Chem. Res. 2015, 48, 3044-3052. (c) Vargas, E. L.; Snurr, R. Q. Langmuir 2015, 31, 10056-10065. (d) Wee, L. H.; Meledina, M.; Turner, S.; Van Tendeloo, G.; Zhang, K.; Rodriguez-Albelo, L. M.; Masala, A.; Bordiga, S.; Jiang, J.; Navarro, J. A.; Kirschhock, C. E.; Martens, J. A.. J. Am. Chem. Soc. 2017, 139, 819-828. (7) Côté, A. P.; Benin, A. I.; Ockwig, N. W.; O'Keeffe, M.; Matzger, A. J.; Yaghi, O. M. Science 2005, 310, 1166-1170. (8) (a) Feng, X.; Ding, X.; Jiang, D. Chem. Soc. Rev. 2012, 41, 6010-6022. (b) Ding, S. Y.; Wang, W. Chem. Soc. Rev. 2013, 42 , 548568. (c) Waller, P. J.; Gandara, F.; Yaghi, O. M. Acc. Chem. Res. 2015, 48, 3053-3063. (9) (a) Doonan, C. J.; Tranchemontagne, D. J.; Glover, T. G.; Hunt, J. R.; Yaghi, O. M. Nat. Chem. 2010, 2, 235-238. (b) Ding, S. Y.; Gao, J.; Wang, Q.; Zhang, Y.; Song, W. G.; Su, C. Y.; Wang, W. J. Am. Chem. Soc. 2011, 133, 19816-19822. (c) DeBlase, C. R.; Silberstein, K. E.; Truong, T. T.; Abruna, H. D.; Dichtel, W. R. J. Am. Chem. Soc. 2013, 135, 16821-16824. (d) Oh, H.; Kalidindi, S. B.; Um, Y.; Bureekaew, S.; Schmid, R.; Fischer, R. A.; Hirscher, M. Angew. Chem., Int. Ed. 2013, 52, 13219-13222. (e) Chandra, S.; Kundu, T.; Kandambeth, S.; Babarao, R.; Marathe, Y.; Kunjir, S. M.; Banerjee, R. J. Am. Chem. Soc. 2014, 136, 6570-6573. (f) Calik, M.; Auras, F.; Salonen, L. M.; Bader, K.; Grill, I.; Handloser, M.; Medina, D. D.; Dogru, M.; Lobermann, F.; Trauner, D.; Hartschuh, A.; Bein, T. J. Am. Chem. Soc. 2014, 136, 17802-17807. (g) Xu, H.; Gao, J.; Jiang, D. Nat. Chem. 2015, 7, 905-912. (h) Fang, Q.; Wang, J.; Gu, S.; Kaspar, R. B.; Zhuang, Z.; Zheng, J.; Guo, H.; Qiu, S.; Yan, Y. J. Am. Chem. Soc. 2015, 137, 8352-8355. (i) Vyas, V. S.; Vishwakarma, M.; Moudrakovski, I.; Haase, F.; Savasci, G.; Ochsenfeld, C.; Spatz, J. P.; Lotsch, B. V. Adv. Mater. 2016, 28, 8749-8754. (j) Ma, H.; Liu, B.; Li, B.; Zhang, L.; Li, Y. G.; Tan, H. Q.; Zang, H. Y.; Zhu, G. J. Am. Chem. Soc. 2016, 138, 5897-5903. (k) Xu, H.-S.; Ding, S.-Y.; An, W.-K.; Wu, H.; Wang, W. J. Am. Chem. Soc. 2016, 138, 11489– 11492. (l) Qian, C.; Qi, Q.-Y.; Jiang, G.-F.; Cui, F.-Z.; Tian, Y.; Zhao, X. J. Am. Chem. Soc., 2017, 139, 6736–6743. (m) Ma, Y.-X.; Li, Z.-J.; Wei, L.; Ding, S.-Y.; Zhang, Y.-B.; Wang, W. J. Am. Chem. Soc., 2017, 139, 4995–4998. (n) Huang, N.; Wang, P.; Addicoat, M. A.; Heine, T.; Jiang, D. Angew. Chem., Int. Ed. 2017, 56, 4982 –4986. (10) (a) Colson, J. W.; Woll, A. R.; Mukherjee, A.; Levendorf, M. P.; Spitler, E. L.; Shields, V. B.; Spencer, M. G.; Park, J.; Dichtel, W. R. Science 2011, 332, 228−231. (b) Spitler, E. L.; Koo, B. T.; Novotney, J. L.; Colson, J. W.; Uribe-Romo, F. J.; Gutierrez, G. D.; Clancy, P.; Dichtel, W. R. J. Am. Chem. Soc. 2011, 133, 19416−19421. (c) Liu, X.-H.; Guan, C.-Z.; Ding, S.-Y.; Wang, W;. Yan, H.-J.; Wang, D.; Wan, L.-J. J. Am. Chem. Soc. 2013, 135, 10470−10474. (d) Rodriguez-San-Miguel, D.; Abrishamkar, A.; Navarro, J. A.; RodriguezTrujillo, R.; Amabilino, D. B.; Mas-Balleste, R.; Zamora, F.; Puigmarti-Luis, J. Chem. Commun. 2016, 52, 9212-9215. (e) Yadav, R. K.; Kumar, A.; Park, N.-J.; Kong, K.-J.; Baeg, J.-O. J. Mater. Chem. A. 2016, 4, 9413-9418. (f) Zhang, S.; Yang, Q.; Li, Z.; Wang, W.; Wang, C.; Wang, Z. Anal. Bioanal. Chem. 2017, 409, 3429-3439. (g) Sun, B.; Zhu, C.-H.; Liu, Y.; Wang, C.; Wan, L.-J.; Wang, D. Chem. Mater. 2017, 29, 4367-4374. (11) (a) Wang. Z.; Cohen, Z.; Chem. Soc. Rev., 2009, 38, 1315– 1329. (b) Gittins, P.; J. Twyman, L. J. J. Am. Chem. Soc., 2005, 127, 1646-1647. (c) Kerneghan, P. A.; Halperin, S. D.; Bryce, D. L.; Maly, K. E. Can. J. Chem. 2011, 89: 577–582. (d) Yarita, N.; Tahara, H.; Saruyama, M.; Kawawaki, T.; Sato, R.; Teranishi, T.; Kanemitsu, Y. J. Phys. Chem. Lett. 2017, 8, 6041−6047. (e) Nagai, A.; Guo, Z.; Feng, X.; Jin, S.; Chen, X.; Ding, X.; Jiang, D. Nature Commun. 2011, 2, 536. (f) Waller, P. J.; Lyle, S. J.; Osborn Popp, T. M.; Diercks, C. S.; Reimer, J. A.; Yaghi. O. M. J. Am. Chem. Soc., 2016, 138, 15519−15522. (g) Sun, Q.; Aguila, B.; Perman, J.; Earl, L.D.; Abney, C. W.; Cheng, Y.; Wei, H.; Nguyen, N.; Wojtas, L.; Ma, S. J.

Page 8 of 9

Am. Chem. Soc., 2017, 139, 2786−2793. (h) Mitra, S.; Sasmal, H. S.; Kundu, T.; Kandambeth, S.; Illath, K.; Díaz, D. D.; Banerjee, R. J. Am. Chem. Soc., 2017, 139, 4513−4520. (12) (a) Rowan, S. J.; Cantrill, S. J.; Cousins, G. R. L.; Sanders, J. K. M.; Stoddart, J. F. Angew. Chem., Int. Ed. 2002, 41, 898-952 (b) Lehn, J.-M. Chem. Soc. Rev., 2007, 36, 151–160. (c) Jin, Y.; Yu, C.; Denman, R. J.; Zhang, W. Chem. Soc. Rev. 2013, 42, 6634-6654. (d) Roy, N,; Bruchmann, B,; Lehn. J. M. Chem. Soc. Rev. 2015, 44, 3786-3807. (13) (a) Duren, T.; Millange, F.; Férey, G.; Walton, K. S.; Snurr, R. Q. J. Phys. Chem. C, 2007, 111, 15351-15356. (b) J.-R.; Li, J.; Sculley, H.-C.; Zhou, Chem. Rev., 2012, 112, 869–932. (14) (a) Spitler, E. L.; Koo, B. T.; Novotney, J. L.; Colson, J. W.; Uribe-Romo, F. J.; Gutierrez, G. D.; Clancy, P.; Dichtel, W. R. J. Am. Chem. Soc., 2011, 133, 19416-19421. (b) Pang, Z.-F.; Zhou, T.-Y.; Liang, R.-R.; Qi, Q.-Y.; Zhao, X. Chem. Sci., 2017, 8, 3866–3870. (15) (a) Hirai, K.; Reboul, J.; Morone, N.; Heuser, J. E.; Furukawa, S.; Kitagawa, S. J. Am. Chem. Soc. 2014, 136, 14966−14973. (b) Zhang, T.; Ge, J.; Hu, Y.; Zhang, Q.; Aloni, S.; Yin, Y. Angew. Chem. Int. Ed. 2008, 47, 5806–5811. (c) Lou, X. W.; Archer, L.A.; Yang, Z. Adv. Mater. 2008, 20, 3987–4019. (16) (a) Li, J.; Zeng, H. C. J. Am. Chem. Soc. 2007, 129, 1583915847. (b) Ghosh, S.; Reches, M.; Gazit, E.; Verma, S. Angew. Chem. Int., Ed. 2007, 46, 2002–2004. (c) Krause, M. R.; Stollenwerk, A. J.; Licurse, M.; LaBella, V. P. Appl. Phys. Lett. 2007, 91, 041903. (d) Huo, J.; Wang, L.; I, E.; Yu, H.; Gao, J.; Fan, D.; Li, B.; Wang, J.; Ding, W.; Amin, A. M.; Li, C.; Ma, L. Angew. Chem., Int. Ed. 2010, 49, 9237-9241. () Lee, I.; Choi, S.; Lee, H. J.; Oh, M. Cryst. Growth. Des. 2015, 15, 5169-5173. (d) Ni, B.; Wang, X. CrystEngComm, 2015, 17, 6796–6808. (f) Kandambeth, S.; Venkatesh, V.; Shinde, D. B.; Kumari, S.; Halder, A.; Verma, S.; Banerjee, R. Nat. Commun. 2015, 6, 6786-1-6786-10. (g) Kim, H.; Lah, M. S. Dalton. Trans. 2017, 46, 6146-6158. (17) (a) Van de Voorde, B.; Boulhout, M.; Vermoortele, F.; Horcajada, P.; Cunha, D.; Lee, J. S.; Chang, J. S.; Gibson, E.; Daturi, M.; Lavalley, J. C.; Vimont, A.; Beurroies, I.; De Vos, D. E. J. Am. Chem. Soc. 2013, 135, 9849-9856. (b) de Lange, M. F.; van Velzen, B. L.; Ottevanger, C. P.; Verouden, K. J.; Lin, L. C.; Vlugt, T. J.; Gascon, J.; Kapteijn, F. Langmuir 2015, 31, 12783-12796. (18) (a) Burtch, N. C.; Jasuja, H.; Walton, K. S. Chem. Rev. 2014, 114, 10575-10612. (b) Canivet, J.; Fateeva, A.; Guo, Y.; Coasne, B.; Farrusseng, D. Chem. Soc. Rev. 2014, 43, 5594-5617. (c) Wang, C.; Liu, X.; Keser Demir, N.; Chen, J. P.; Li, K. Chem. Soc. Rev. 2016, 45, 5107-5134. (19) (a) Stegbauer, L.; Hahn, M. W.; Jentys, A.; Savasci, G.; Ochsenfeld, C.; Lercher, J. A.; Lotsch, B. V. Chem. Mater. 2015, 27, 7874-7881. (b) Karak, S.; Kandambeth, S.; Biswal, B. P.; Sasmal, H. S.; Kumar, S.; Pachfule, P.; Banerjee, R. J. Am. Chem. Soc. 2017, 139, 1856-1862. (20) (a) Furukawa, H.; Gandara, F.; Zhang, Y. B.; Jiang, J.; Queen, W. L.; Hudson, M. R.; Yaghi, O. M. J. Am. Chem. Soc. 2014, 136, 4369-4381. (b) Kim, H.; Yang, S.; Rao, S. R.; Narayanan, S.; Kapustin, E. A.; Furukawa, H.; Umans, A. S.; Yaghi, O. M.; Wang, E. N. Science 2017, 356, 430-434. (21) (a) Chen, X.; Addicoat, M.; Irle, S.; Nagai, A.; Jiang, D. J. Am. Chem. Soc. 2013, 135, 546-549. (b) Chen, X.; Addicoat, M.; Jin, E.; Zhai, L.; Xu, H.; Huang, N.; Guo, Z.; Liu, L.; Irle, S.; Jiang, D. J. Am. Chem. Soc. 2015, 137, 3241-3247. (c) Huang, N.; Zhai, L.; Coupry, D. E.; Addicoat, M. A.; Okushita, K.; Nishimura, K.; Heine, T.; Jiang, D. Nat. Commun. 2016, 7, 12325. (d) Pang, Z. F.; Xu, S. Q.; Zhou, T. Y.; Liang, R. R.; Zhan, T. G.; Zhao, X. J. Am. Chem. Soc. 2016, 138, 4710-4713.


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Construction of a Hierarchical Architecture of Covalent Organic

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