2D Covalent Organic Frameworks with Alternating Triangular and

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2D Covalent Organic Frameworks with Alternating Triangular and Hexagonal Pores Luke A. Baldwin, Jonathan W. Crowe, Matthew D Shannon, Christopher P. Jaroniec, and Psaras L. McGrier Chem. Mater., Just Accepted Manuscript • DOI: 10.1021/acs.chemmater.5b02053 • Publication Date (Web): 27 Aug 2015 Downloaded from http://pubs.acs.org on August 31, 2015

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Chemistry of Materials

2D Covalent Organic Frameworks with Alternating Triangular and Hexagonal Pores Luke A. Baldwin‡, Jonathan W. Crowe‡, Matthew D. Shannon, Christopher P. Jaroniec, and Psaras L. McGrier* Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States Supporting Information Covalent organic frameworks (COFs)1,2 are an incipient class of porous crystalline materials that have attracted considerable attention for applications related to gas stor-‐ age3, separations4, optoelectronics5-‐7, and catalysis8,9. The modular nature of COFs permits the integration of vari-‐ ous rigid π-‐conjugated molecular building blocks into highly ordered columnar periodic arrays producing poly-‐ meric materials that exhibit low densities, permanent porosity and high thermal stabilities. Many COFs are gen-‐ erally constructed through a dynamic nucleation-‐ elongation process to produce the desired highly ordered polymeric networks.10,11 Utilizing this process, two-‐ dimensional (2D) and three-‐dimensional (3D)12 COFs have been synthesized with imine13, boronate ester14, bo-‐ razine15, and hydrazone16 bond linkages. The predictable design and applicability of various bond linkages has enabled the creation of many distinctive COFs with tunable pore sizes. Although the pore size and shape can be modulated by meticulous selection of the monomer, finding ways to incorporate functional mono-‐ mers that can bind analytes (i.e. metal cations) or interact selectively with guest molecules without compromising the surface area and pore volume of the materials is still a particular challenge. However, Zhao and coworkers have recently shown that the careful choice of monomers can lead to a 2D COF structure with a mixture of micro-‐ and mesopores utilizing a one step polycondensation reac-‐ tion.17 However, the micropore of the COF investigated in this report relies upon monomers with D2h and C2 symme-‐ tries, which can limit the control over the specific size of the micropore as the lengths of the C2-‐symmetric mono-‐ mers are protracted. Having precise control over the size of the micropore is important for designing functional multipore COF architectures that can interact with specif-‐ ic analytes as the pore size is extended to increase the surface area of the material. Jiang and coworkers recently reported utilizing a C3-‐symmetric phenanthrene cyclotri-‐ mer and C2-‐symmetric monomers to construct star-‐ shaped multipore 2D COFs, which demonstrated the po-‐ tential of employing a macrocycle to control the mi-‐ cropore of 2D COFs.18 Such investigations are imperative

Scheme 1. Synthesis of DBA-‐COF 1 and DBA-‐COF 2 using DBA monomers and a diboronic acid linker. HO OH HO OH

DBA[12]

DBA[18] OH OH

HO HO

2:1 Dioxane / Mesitylene 105 °C / 3 days

HO HO

HO OH B

B HO OH

OH OH

2:1 Dioxane / Mesitylene 105 °C / 3 days

B O O B O O

O BO

O OB

O BO

OB O

BO O

OB O

BO O

O O B

BO O

O O B

O O B

B O O

B

B O O

O BO

O OB OB O

BO O

BO O

OB O

O O B

DBA-COF 2

DBA-COF 1

O BO

O OB

OB O

B O O

O O

O OB

O BO

O OB

O BO BO O

O OB

OB O

O O B O O B

__________________________________________________ for advancing the structural diversity of this advanced class of polymeric materials. Herein, we report the synthesis of two 2D COFs with a mixture of alternating triangular and hexagonal pores utilizing C3-‐symmetric π-‐conjugated dehydrobenzoannu-‐ lenes (DBAs)19 and a C2 symmetric 1,4-‐benzenediboronic acid (BDBA) monomer. DBAs are planar macrocycles that exhibit the ability to form ordered 2D porous net-‐ works20,21, and the potential to bind low oxidation state transition metals.22 Both features make DBAs attractive monomers to utilize for the construction of a distinct class of functional COFs. We demonstrate that the size of the micropore (0.4 nm to 0.5 nm) and mesopore (3.2 nm to 3.6 nm) can be tuned by extending the length of the DBA monomer by adding three additional alkynyl units to yield periodic crystalline networks with very high surface areas.23 DBA-‐COF 1 and DBA-‐COF 2 were synthesized under solvothermal conditions by reacting DBA[12] and DBA[18] monomers24 with BDBA in a 2:1 (v/v) 1,4-‐dioxane and me-‐ sitylene mixture in flame sealed glass ampules at 105 °C for 3 days. DBA-‐COF 1 and DBA-‐COF 2 were obtained by

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tion of 13C types based on their proximity to 1H nuclei. Specifically, for 13C atoms with directly bonded protons, significant dipolar dephasing of the 13C spectral intensity is observed for short (~100 µs) recoupling times. In con-‐ trast, longer dipolar recoupling periods (~1-‐2 ms) are re-‐ quired to modulate the resonance intensities for the re-‐ maining carbons, with the extent of dephasing correlated with the distance to the nearest proton. Scanning electron microscopy (SEM) images revealed hexagonal crystallites and one bulk phase morphology for both COFs (Figure S20 & S21, SI).

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Figure 1. Indexed experimental (red) and Pawley refined (blue) PXRD patterns of DBA-‐COF 1 (top) and DBA-‐COF 2 (bottom) compared to the bnn simulated unit cell (green) with views along the c and b directions for each hexagonal crystal model.

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filtration and washed with acetonitrile to afford green crystalline powders that were insoluble in common or-‐ ganic solvents. The COF materials were purified by im-‐ mersing them in acetonitrile for 24 h to remove unreacted monomers and dried under vacuum (SI). Thermogravi-‐ metric analysis (TGA) revealed that DBA-‐COF 1 main-‐ tained more than 97% of its weight up to 465 °C (Figure S10, supporting information (SI)) while DBA-‐COF 2 main-‐ tained ~ 80% of its weight up to the same temperature (Figure S11, SI). DBA-‐COF 1 and DBA-‐COF 2 were characterized by Fou-‐ rier transform infrared (FT-‐IR) and 13C cross-‐polarization magic angle spinning (CP-‐MAS) spectroscopies. The FT-‐ IR spectra of DBA-‐COF 1 and DBA-‐COF 2 showed stretch-‐ ing modes at 1326 cm-‐1 and 1329 cm-‐1, respectively, which is indicative of boronate ester (B-‐O) formation (Figure S1 & S2, SI). Solid-‐state 13C CP-‐MAS NMR was used to estab-‐ lish the connectivity of the COF materials. The presence of alkynyl units was confirmed via the characteristic reso-‐ nance at 94.0 ppm for DBA -‐COF 1 and two signals at 78.6 and 83.2 ppm for DBA-‐COF 2 (Figure S9, SI). For both COF materials the spectra also contain all the expected 13C resonances in the 120-‐160 ppm region and no other sig-‐ nals. To assign the 13C resonances, in addition to utilizing the general chemical shift trends, we performed R1871 1H-‐ 13 C dipolar recoupling experiments34 for DBA-‐COF 1 (Fig-‐ ure S8, SI). These measurements enable the differentia-‐

Powder x-‐ray diffraction (PXRD) was used to assess the crystallinity and unit cell parameters of DBA-‐COF 1 and DBA-‐COF 2. Figure 1 shows the experimental and refined PXRD profiles for both COFs, which were indexed using a primitive hexagonal lattice. Since the both DBA mono-‐ mers are C3-‐symmetric, it was anticipated that combining DBA[12] or DBA[18] with the linear C2-‐symmetric BDBA building block would yield ordered 2D hexagonal layers. We predicted that these layers would pack in eclipsed bnn (P6/mmm) or staggered gra (P63/mmc) confor-‐ mations. DBA-‐COF 1 displays intense peaks at 3.01, 5.16, 5.93, 7.83, 10.65, and 26.1° which corresponds to the (100), (110), (200), (210), (310), and (001) planes, respectively. The broad reflection peak at 26.1 corresponding to the (001) reflection plane highlights the vertical spacing between the stacked COF layers at a distance of 3.4 Å. The crystal structure of DBA-‐COF 1 was simulated using the Reflex module of the Materials Studio 7.0 software. Pawley re-‐ finement of the observed PXRD data using a bnn net pro-‐ vided unit cell parameters of a=b= 33.929 Å and c= 3.4 Å (residuals Rp = 6.89%, Rwp = 8.83%). The diffraction peaks for DBA-‐COF 2 are analogous to DBA-‐COF 1 displaying intense peaks at 2.67, 4.55, 5.23, 6.92, 9.44, and 26.2 corre-‐ sponding to the (100), (110), (200), (210), (310), and (001) planes, respectively. The unit cell was also refined using a bnn net to provide parameters of a=b= 37.889 Å and c= 3.4 Å (residuals Rp = 3.86%, Rwp = 4.96%). With an inter-‐ layer spacing of 3.4 Å, the butadiyne units of DBA[18] are not in close enough proximity to undergo polymeriza-‐ tion,25 an observation that is consistent with another pre-‐ viously reported COF using a similar butadiyne building block.26 Although the simulated PXRD patterns were in good agreement with the experimental peak positions for DBA-‐COF 1 and DBA-‐COF 2, computational studies have shown28 that the adjacent layers of most COFs are slightly offset from their completely eclipsed bnn packing struc-‐ ture. We also considered gra PXRD patterns in which the a and b planes are offset by half of the unit cell for both materials (Figure S5 & S7, SI). However, the simulated PXRD patterns could not reproduce the experimental peak intensities. The permanent porosity of DBA-‐COF 1 and DBA-‐COF 2 were determined by nitrogen gas adsorption measure-‐ ments at 77 K. DBA-‐COF 133 exhibits a type IV isotherm displaying a sharp uptake under low relative pressure (P/P0 < 0.01) followed by a sharp step between P/P0= 0.04 -‐ 0.21, which is indicative of a mesoporous material (Fig-‐ ure 2a). The Brunauer-‐Emmett-‐Teller (BET) model was


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spectra of DBA-‐COF 2 is within the range of the absorption maximum of DBA[18], but the powders are not fluorescent under UV illumination at 365 nm (Figure S16, SI). The reason for the dramatic difference in the lumi-‐ nescent properties of DBA-‐COF 1 and DBA-‐COF 2 is not well understood. We believe the extended size of the DBA[18] vertices leads to additional offsets, which could limit their coplanar interactions with the adjacent layers. __________________________________________________

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Figure 2. Nitrogen adsorption isotherms for DBA-‐COF 1 (a) and DBA-‐COF 2 (b) measured at 77 K followed by NLDFT pore size distributions of DBA-‐COF 1 (c) and DBA-‐COF 2 (d).

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applied over the low-‐pressure region (0.04 < P/P0 < 0.18) of the isotherm providing a surface area of 1952 m2 g-‐1. This value is very close to the predicted Connolly surface area value of 2085 m2 g-‐1 allowing us to activate up to 90% of its maximum nitrogen uptake. It should also be noted that the BET surface area of DBA-‐COF 1 is larger than COF-‐5 (1590 m2 g-‐1)1, NTU-‐COF-‐2 (1619 m2 g-‐1)27, COF-‐10 (1760 m2 g-‐1)3, and TT-‐COF (1810 m2 g-‐1)7. Its total pore volume calculated at P/P0 = 0.993 was 1.27 cm3/g, which is also close to the theoretical value of 1.32 cm3/g. DBA-‐COF 2 also exhibits a type IV isotherm indicative of a mesopo-‐ rous material. Application of the BET model over the low pressure 0.08 < P/P0 < 0.21 range provided a surface area of 984 m2 g-‐1, which is significantly lower than the pre-‐ dicted Connolly surface area of 2166 m2 g-‐1. We attribute the lower surface area to the presence of unreacted mon-‐ omers trapped within the 1D hexagonal channels of the material. However, further optimization to attain its theo-‐ retical value is ongoing. The total pore volume of DBA-‐ COF 2 calculated at P/P0 = 0.997 was 0.741 cm3 g-‐1. The nonlocal density functional theory (NLDFT) was used to estimate the pore size distributions of DBA-‐COF 1 and DBA-‐COF 2 yielding average pore sizes of 3.2 and 3.6 nm, respectively. The observed pore sizes for DBA-‐COF 1 and DBA-‐COF 2 are very close to the predicted values of 3.4 nm and 3.8 nm, respectively, utilizing the bnn crystal models. However, we were not able to confirm the pres-‐ ence of the predicted micropore values of 0.4 nm and 0.5 nm for DBA[12] and DBA[18], respectively. We attribute this to possible defects and offsets between the stacked layers of the materials, which is a typical phenomenon that has been observed with other COFs.28 Interestingly, DBA-‐COF 1 powders are highly fluores-‐ cent in the solid-‐state on account of the coplanar ar-‐ rangement of the DBA[12] vertices (Figure 3c). UV-‐vis diffuse reflectance spectra show that the material absorbs within 310-‐380 nm range which is consistent with the ab-‐ sorption maximum of DBA[12] in THF (Figure S12 in the SI). The solid-‐state emission spectra exhibits a λmax of 530 nm (λexc= 365 nm), which is red-‐shifted by ~10 nm from DBA[12] in THF (Figure S13, SI). The diffuse reflectance

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Figure 3. Kubelka-‐Munk function diffuse reflectance (a), emission spectrum (b), and photograph (c) of DBA-‐COF 1 powder (λexc=365 nm), respectively. A photograph of the flu-‐ orescent powder was taken using a handheld UV-‐lamp at 365 nm.

__________________________________________________ In conclusion, we have demonstrated that DBA mono-‐ mers can be used to construct multipore COFs with high surface areas and unique luminescent properties. Alt-‐ hough luminescent COFs could be useful for developing solid-‐state materials for sensory-‐based applications29, we also believe the proof-‐of-‐principle is important as theoret-‐ ical studies have shown that DBA monomers exhibit the potential to strongly bind not only alkali and alkaline earth metals, but also low oxidation state transition met-‐ als.30 Incorporating metals at the vertices of 2D DBA-‐ based COFs raises the possibility of developing novel functional COF materials with enhanced binding sites for separations31 and gas storage applications.32 Such investi-‐ gations are currently underway in our laboratory and will be reported in the near future. Supporting Information Synthetic procedures, FT-‐IR, PXRD, solid state 13C NMR, TGA and SEM. This material is available free of charge via the internet at http://pubs.acs.org.

AUTHOR INFORMATION Corresponding Author *[email protected] Author Contributions ‡ L.B and J.C contributed equally to this work. Notes The authors declare no competing financial interests.

ACKNOWLEDGMENTS P.L.M acknowledges the National Science Foundation (NSF) and Georgia Tech Facilitating Academic Careers in Engineering and Science (GT-‐FACES) for a Career Initia-‐ tion Grant, and funding from The Ohio State University.



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REFERENCES (1) Côté, A.P.; Benin, A.I; Ockwig, N.W; O’Keeffe, M.; Matzger, A.J.; Yaghi, O. M. Porous, Crystalline, Covalent Organic Frameworks Science 2005, 310, 1166-‐1170. (2) Feng, X. Ding, X. Jiang, D. Covalent organic frameworks. Chem Soc. Rev. 2013, 41, 6010-‐6022 (3) Furukawa, H.; Yaghi, O. M. Storage of Hydrogen, Methane, Carbon Dioxide in Highly Porous Covalent Organic Frameworks for Clean Energy Applications. J. Am. Chem. Soc. 2009, 131, 8875-‐ 8883. (4) Oh, H.; Kalidini, S.B; Um, Y; Bureekaew, S.; Schmid, R.; Fischer, R.A.; Hirsher, M. A Cryogenically Flexible Covalent Or-‐ ganic Framework for Efficient Hydrogen Isotope Separation by Quantum Sieving. Angew. Chem. Int. Ed., 2013, 52, 13219-‐13222. (5) Wan, S.; Guo, J.; Kim, J.; Ihee, H; Jiang, D. A Belt-‐Shaped Blue Luminescent, Semiconducting Covalent Organic Frame-‐ work. Angew. Chem., Int. Ed. 2008, 47, 8826-‐8830. (6) Bertrand, G. H. V.; Michaelis, V. K.; Ong, T.-‐C.; Griffin, R. G.; Dincă, M. Thiophene-‐Based Covalent Organic Frameworks. Proc. Natl. Acad. Sci U. S. A. 2013, 110, 4923-‐4928. (7) Dogru, M.; Handloser, M.; Auras, F.; Kunz T.; Medina, D.; Hartschuh, A.; Knochel, P; Bein T. A Photoconductive Thienothiophene-‐Based Covalent Organic Framework Showing Charge Transfer Towards Included Fullerene. Angew. Chem., Int. Ed. 2013, 52, 2920-‐2924. (8) Ding, S.-‐Y.; Gao, J.; Wang, Q; Zhang, Y.; Song, W.-‐G.; Su, C.-‐Y.; Wang, W. Construction of Covalent Organic Framework for Catalysis: Pd/COF-‐LZU1 in Suzuki-‐Miyaura Coupling Reac-‐ tion. J. Am. Chem. Soc. 2011, 133, 19816-‐19822. (9) Fang, Q.; Gu, S.; Zheng, J.; Zhuang, Z.; Qiu, S; Yan, Y. 3D Microporous Base-‐Functionalized Covalent Organic Frameworks for Size-‐Selective Catalysis. Angew. Chem., Int. Ed. 2014, 53, 2878-‐ 2882. (10) Smith, B.J.; Dichtel, W. R. Mechanistic Studies of two-‐ dimensional Covalent Organic Frameworks Rapidly Polymerized from Initially Homogeneous Conditions. J. Am. Chem. Soc. 2014, 136, 8783-‐8789. (11) Smith, B.J.; Hwang, N.; Chavez, A.D. Novotney, J. L.; Dichtel, W. R. Growth rates and water stability of 2D boronate-‐ ester covalent organic frameworks. Chem. Commun. 2015, 51, 7532-‐7535. (12) El-‐Kaderi, H. M.; Hunt, J.R.; Mendoza-‐Cortes, J. L.; Côté, A.P.; Taylor, R. E.; O’Keeffe, M. O.; Yaghi, O. M. Designed Syn-‐ thesis of 3D Covalent Organic Frameworks. Science 2007, 316, 268-‐272. (13) Das, G.; Shinde D. B.; Kandambeth, S.; Biswal, B. P.; Banerjee, R. Mechanosynthesis of Imine, β-‐ketoenamine, Hydro-‐ gen-‐bonded imine-‐linked Covalent Organic Frameworks using Liquid Assisted Grinding. Chem. Commun. 2014, 50, 12615-‐12618. (14) Tilford, R. W.; Gemmil, W. R.; zur Loye, H.-‐C.; Lavigne, J. J. Facile Synthesis of a Highly Crystalline Covalently Linked Po-‐ rous Boronate Network. Chem. Mater. 2006, 18, 5296-‐5301. (15) Jackson, K. T.; Reich, T. E.; El-‐Kaderi, H. M. Targeted Syn-‐ thesis of a Porous Borazine-‐Linked Covalent Organic Framework Chem. Commun. 2012, 48, 8823-‐8825. (16) Uribe-‐Romo, F. J.; Doonan, C. J.; Furukawa, H.; Oisaki, K.; Yaghi, O. M. Crystalline Covalent Organic Frameworks with Hydrazone Linkages. J. Am. Chem. Soc. 2011, 133, 11478-‐11481. (17) Zhou, T.-‐Y.; Xu, S.-‐Q.; Wen, Q.; Pang, Z.-‐F.; Zhao, X. One-‐Step Construction of Two Different Kinds of Pores in a 2D Covalent Framework. J. Am. Chem. Soc. 2014, 136, 15885-‐15888. (18) Feng, X.; Dong, Y.; Jiang, D. Star-‐shaped two-‐dimensional covalent organic frameworks. CrystEngComm 2013, 15, 1508-‐1511. (19) Spitler, E. L.; Johnson II, C. A.; Haley, M. M. Renaissance of Annulene Chemistry. Chem Rev. 2006, 106, 5344-‐5386.

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(20) Tahara, K.; Furukawa, S.; Uji-‐I, H.; Uchino, T.; Ichikawa, T.; Zhang, J.; Mamdouh, W.; Sonoda, M.; De Schryver, F. C.; De Feyter, S.; Tobe, Y. Two-‐Dimensional Porous Networks of Dehy-‐ drobenzo[12]annulene Derivatives via Alkyl Chain Interdigita-‐ tion. J. Am. Chem. Soc. 2006, 128, 16613-‐16625. (21) Tahara, K.; Johnson II, C. A.; Fujita, T.; Sonoda, M.; De Schryver, F. C.; De Feyter, S.; Haley, M. M. Tobe, Y. Synthesis of Dehydrobenzo[18]annulene Derivatives and Formation of Self Assembled Monolayers: Implications of Core Size on Alkyl Chain Interdigitation. Langmuir 2007, 23, 10190-‐10197. (22) Youngs, W. J.; Tessier, C. A.; Bradshaw, J. D. ortho-‐Arene Cyclynes, Related Heterocyclynes, and Their Metal Chemistry. Chem. Rev. 1999, 99, 3153-‐3180. (23) A 2D mulitporous supramolecular network utilizing do-‐ decadehydorbenzo[18]annulene has been reported recently. However, the network is connected via hydrogen bonds and is not covalent bonds. See Hisaki, I.; Nakagawa, S.; Tohnai, N.; Miyata, M. A C3-‐Symmetric Macrocycle-‐Base, Hydrogen Bond-‐ ed, Multiporous Hexagonal Network as a Motif of Porous Mo-‐ lecular Crystals. Angew. Chem., Int. Ed. 2015, 54, 3008-‐3012. (24) The number in brackets denotes the number of sp and sp2 hybridized carbon atoms within the triangular pore. (25) Coates, G. W.; Dunn, A. R.; Henling, L.M.; Dougherty, D. A.; Grubbs, R. H.Phenyl-‐Perfluorophenyl Stacking Interactions: A New Strategy for Supermolecuale Construction. Angew. Chem., Int. Ed. 1997, 36, 248-‐251. (26) Spitler, E. L.; Koo, B. T.; Novotney, J. L.; Colson, J. W.; Uribe-‐Romo, F. J.; Gutierrez, G. D.; Clancy, P.; Dichtel W. R. A 2D Covalent Organic Framework with 4.7-‐nm Pores and Insight into Its Interlayer Stacking. J. Am. Chem. Soc. 2011, 133, 19416-‐ 19421. (27) Zeng, Y.; Zou, R. Luo, Z.; Zhang, H.; Yao, X. Ma, X.; Zou, R.; Zhao, Y. Covalent Organic Frameworks Formed with Two types of Covalent Bonds Based on Orthogonal Reactions. J. Am. Chem. Soc. 2015, 137, 1020-‐1023. (28) Koo, B. T.; Dichtel, W. R.; Clancy, P. A classification scheme for the stacking of two-‐dimensional boronate ester-‐ linked covalent organic frameworks. J. Mater. Chem. 2012, 22, 17460-‐17469. (29) Das, G.; Biswal, B. P.; Kandambeth, S.; Venkatesh, V.; Kaur, G.; Addicoat, M.; Heine, T.; Verma, S.; Banerjee, R. Chemi-‐ cal sensing in two-‐dimensional porous covalent organic nanosheets. Chem. Sci. 2015, 6, 3931-‐3939. (30) Li, Y.; Xu, L.; Liu, H.; Li, Y. Graphdiyne and graphyne: from theoretical predictions to practical construction. Chem Soc. Rev. 2014, 43, 2572-‐2586. (31) Li, B.; Zhang, Y.; Krishna, R.; Yao, K.; Han, Yu, H.; Wu, Z.; Ma, D.; Shi, Z.; Pham, T.; Space, B.; Liu, J.; Thallapally, P. K.; Liu, J.; Chrzanowski, Ma, S. Introduction of π-‐complexation into Po-‐ rous Aromatic Framework for Highly Selective Adsorption of Ethylene over Ethane. J. Am. Chem. Soc. 2014, 136, 8654-‐8660. (32) Lan, J.; Cao, D.; Wang, W.; Smit, B. Doping of Alkali, Al-‐ kaline-‐Earth, and Transition Metals in Covalent-‐Organic Frameworks for Enhancing CO2 capture by First-‐Principles Cal-‐ culations and Molecular Simulations. ACS Nano 2010, 4, 4225-‐ 4237. (33) A COF using a DBA[12] monomer was recently reported using a different method providing a lower surface area. Also, the luminescent properties of the material were not reported. See Yang, H.; Du, Y.; Wan, S.; Trahan, G.D. Jin, Y.; Zhang, W. Mesoporous 2D Covalent Organic Frameworks Based on Shape-‐ Persistent Arylene-‐Ethynylene Macrocycles. Chem. Sci. 2015, 6, 4049-‐4053. (34) Levitt, M. H. Symmetry in the design of NMR multiple-‐ pulse sequences. J. Chem. Phys. 2008, 128, 052205.


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2D Covalent Organic Frameworks with Alternating Triangular and

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