- Email: [email protected]
High-yield postsynthetic modification of MOF with organic–metal precursors
Inorganica Chimica Acta 390 (2012) 22–25
Contents lists available at SciVerse ScienceDirect
Inorganica Chimica Acta journal homepage: www.elsevier.com/locate/ica
Note
High-yield postsynthetic modification of MOF with organic–metal precursors Jongsik Kim ⇑,1, Dong Ok Kim 1, Dong Wook Kim, Jeasung Park, Mi Sun Jung Hanwha Chemical Research & Development Center, 6, Shinseong-dong, Yuseong-gu, Daejeon 305-804, Republic of Korea
a r t i c l e
i n f o
Article history: Received 4 January 2012 Received in revised form 8 April 2012 Accepted 12 April 2012 Available online 21 April 2012 Keywords: Postsynthetic modification Metal–organic framework Organic–metal precursor BET Isopropoxytitanatrane Tetrabenzyl titanium
a b s t r a c t The specific yield of postsynthetic modification for modified IRMOF-16 (HCC-1), synthesized using 1,4di(4-carboxy-2-hydroxyphenyl)benzene as organic ligand and Zn(NO3)26H2O as metal source, respectively, has been investigated with the variation of its BET surface area, reaction time and organic–metal precursor. Two kinds of HCC-1 having different values of BET surface area (HCC-1H: 3000 m2/g and HCC-1L: 2000 m2/g) were prepared via solvothermal method for the study of effect of BET surface area, whereas isopropoxytitanatrane and tetrabenzyl titanium were adopted as organic–metal precursors It was observed that even if the specific yields of postsynthetic modification for both organic–metal precursors increased with the value of BET surface area of HCC-1, isopropoxytitanatrane showed relatively higher values than those of tetrabenzyl titanium during the entire range of reaction. These observations led us to conclude that HCC-1H has higher specific number of –OH groups, active sites for postsynthetic modification, and tetrabenzyl titanium experiences more difficulty in diffusing deep into HCC-1 due to its relatively larger molecular size. For the effect of reaction time, while it increased slowly with the reaction time until 48 h and then leveled off for HCC-1H, it increased during the entire range of reaction time for HCC-1L. Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved.
1. Introduction MOFs, having a variety of structures and properties, have been intensively synthesized and studied throughout the world since Yaghi’s group synthesized MOF-5 and reported its structure in the late 1990s [1]. Since it usually consists of two main parts, linker (organic ligand) and node (metal cluster), numerous kinds of MOFs having different structures and properties can be generated simply by changing the combination of these two parts. Furthermore, more precise control of either their pores sizes or shapes is also possible through the molecule-based designs of linker (organic ligand) and node (metal cluster), and it makes them more competitive novel materials than other porous materials such as silica, zeolites and hyper cross-linked polymer particles [2–8]. However, while deepening our knowledge of MOFs, it was suggested that postsynthetic modification of MOF could be far more efficient way to provide MOFs with a variety of functionalities and novel physical properties compared to painstaking jobs, design and synthesis of new MOFs. Thus, some frontier researchers showed successful postsynthetic modifications of MOFs which were applicable to the various fields [9–14]. However, because aforementioned MOFs had relatively smallsized pores, effective postsynthetic modification, especially with ⇑ Corresponding author. Tel.: +82 10 2084 6666; fax: +82 42 865 6570. 1
E-mail address: [email protected] (J. Kim). Contributed equally to this work.
chemical reagents having large and bulky molecular structure, was difficult. Furthermore, since they simply reported the yield of postsynthetic modification instead of the specific yield of postsynthetic modification (the calculated yield of postsynthetic modification based on the perfect-structured MOF), it was difficult to speculate how much additional postsynthetic modification could be achieved if MOFs having more ordered structure were adopted. It is needless to say that the power for characteristic function of postsynthetic modified MOFs is dependent on the specific number of active site.
2. Experimental and results On the basis of above previous researches, we fully understood the importance of postsynthetic modification technology of MOFs and started systematic research. As a first step, a homologous series of p-terphenyl-4,40 -dicarboxylic acid having hydroxyl side groups, ranging from 0 to 4, as functional groups has been synthesized for linkers. Then the first modified IRMOF-16 (HCC-1) has been successfully synthesized via solvothermal method using one of above linkers, 1,4-di(4-carboxy-2-hydroxyphenyl)benzene, as organic ligand and Zn(NO3)26H2O as metal source respectively [15]. Thus HCC-1, having cubic structure with each axis of 21.45 Å, provided us with an opportunity to start more systematic investigation of the postsynthetic modification. In this communication we present the highlights of our findings during the postsynthetic modification
0020-1693/$ - see front matter Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ica.2012.04.020
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25
of HCC-1 with organic–metal precursors, isopropoxytitanatrane [16] and tetrabenzyl titanium [17–21]. The methodical investigation about the postsynthetic modification of HCC-1 germane to its specific yield could be accomplished only after fulfilling two prerequisites, namely, adjusting the number of exposed active site (accessible hydroxyl functional group) of HCC-1 and minimizing the contents of impurities to possibly block the HCC-1’s pores. In terms of meeting these prerequisites, two kinds of HCC-1 samples having different values of BET surface area, 2000 m2/g (HCC-1L) and 3000 m2/g (HCC-1H) were strategically synthesized by applying different synthetic methods (Fig. S2). The difference of BET surface areas between two HCC1s would be owing to the degree of removal upon unreacted organic ligand, undesirably formed oligomeric compounds of that, and reaction solvent (DMF). Specifically, the decantation of reaction mixtures was commonly applied to the synthesis of these MOFs as the first activation step. Furthermore, being delineated in our previous journal [15], CO2 supercritical drying method (SCD) was proved to be undeniably efficient for the elimination of abovementioned impurities in HCC-1’s pores. As a result, this process was adopted as the third activation step for HCC-1H, and the second one for HCC-1L, respectively. On top of that, in the event of the facile preparation of HCC-1H, it is a renowned fact that DMF has a high tendency to generate bonding with the hydrogen atom of hydroxyl functional group presented in HCC-1’s pore via hydrogen bonding mechanism. As a result, with a view to minimizing the chance to form this bonding, conventional solvent exchange method to substitute DMF for chloroform was conducted in the second activation step. Moreover, the chloroform, relatively possessing higher solubility in the supercritical CO2 phase (mimic to the liquid pentane) as well as higher capability to solve the first two of aforementioned impurities than those of DMF, enabled these impurities to be removed more prom-
23
inently. As the final activation step to be followed by carrying out the SCD process, additional vacuum drying (180 °C for 6 h) was executed for the purpose of completely eliminating the trace amount of chloroform (boiling point: 61.2 °C) effectively. For reference, the systematic approach relevant to the maximization of BET surface area for the HCC-1 and its optimization is ongoing. Postsynthetic modifications of HCC-1s with isopropoxytitanatrane and tetrabenzyl titanium have been performed as shown in Fig. 1. Detailed procedures and conditions for measuring BET values, synthesizing MOF and postsynthetic modification are summarized in supporting information. Furthermore, it is worth while noting at this point that CO2 supercritical drying process had been performed after every postsynthetic modification to make sure of the complete elimination of reaction medium solvent and unreacted organic–metal precursors from the MOF complex. Fig. 2 shows the variations of surface morphologies and X-ray diffraction (XRD) patterns of HCC-1 with postsynthetic modifications. It was observed that the surface morphology of HCC-1 remained more or less unchanged but the peak intensity of XRD decreased considerably for both organic–metal precursors. However, any change in XRD pattern suggesting the formation of new phase was not observed. Similar observation, the decline in XRD peak intensity without structural collapse, has been also widely reported in previous researches and regarded as one of good signs for successful postsynthetic modification [9–14]. Another good sign was observed in the analysis of BET surface areas for the prepared samples in that the values of these areas decreased remarkably and consistently after conducting postsynthetic modification of HCC-1s (Table S1). These phenomena were also reported to be a generally acceptable evidence for the successful postsynthetic modification of MOF [9–14]. Besides, as shown in Fig. S7, N2 isotherms, which ultimately evaluate the pore volume and pore size, of the prepared samples typically revealed
Fig. 1. Schematic presentation of postsynthetic modification of HCC-1.
24
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25
Fig. 2. Variations of SEM image and X-ray diffraction pattern after postsynthetic modification of (a) HCC-1H with (b) isopropoxytitanatrane and (c) tetrabenzyl titanium for 48 h.
synthesized IRMOF-16, having the same molecular structure as HCC-1 but no functional group, with tetracyclohexyl titanium. In this case, no Ti was observed, and it was clear enough for us to conclude that hydroxyl group of HCC-1 was a sole reaction site for postsynthetic modification with tetracyclohexyl titanium. The specific yields of HCC-1H (circles) showed much higher values compared with those of HCC-1L (rectangles) during the entire range of reaction time for both organic–metal precursors. As explained in supporting information, it is speculated that higher specific yields of HCC-1H are caused by the fact that the accessible specific number of hydroxyl functional groups (sole reaction site for postsynthetic modification) is proportional to the value of BET surface area. Besides BET effect, the effect of molecular structure of organic– metal precursor on the yield of postsynthetic modification was also clearly observed. In other words, the levels of specific yield for tetrabenzyl titanium were much lower compared with those of isopropoxytitanatrane regardless of BET values. It’s not difficult to imagine that relatively larger and bulkier molecular structure of tetrabenzyl titanium made its diffusion depth into HCC-1 relatively shallow and caused lower specific yield. Moreover, the increases of specific yields with BET value at given reaction times for tetrabenzyl titanium were much smaller than those of isopropoxytitanatrane, and this drove us to suppose one more thing that even if accessible specific number of functional side group increases, it’s rather difficult to obtain higher specific yield of postsynthetic modification in case of bulky structured organic–metal precursor. 3. Conclusions In summary, the value of BET surface area and molecular structure of organic–metal precursor were proven to be very important factors for obtaining higher yield of postsynthetic modification because the accessible specific number of hydroxyl functional side groups in HCC-1 was found to be proportional to its BET value and smaller size of organic–metal precursor was more desirable for effective diffusion into HCC-1. Based on the results of experiments, it was confirmed that HCC-1 complex having more than 8 wt.% of Ti, metalation at an atomic level, was successfully synthesized via postsynthetic modification. This result will be a very important and meaningful step for the application of postsynthetic modification technology to the chemical reaction catalyst, special purpose membrane, selective gas absorption material and etc. Appendix A. Supplementary material
Fig. 3. The variations of specific yield of postsynthetic modification of HCC-1 with reaction time and organic–metal precursors [isopropoxytitanatrane (solid lines) and tetrabenzyl titanium (dotted lines)].
type-I behavior indicating a steep increase in adsorption at P/ P0 0.0 owing to the rapid filling of nitrogen in the well-defined micropores as well as no significant hysteresis. In addition to observations made by SEM and XRD, the elemental analysis of Ti via X-ray fluorescence (XRF), was performed in an effort to observe the variations of specific yield of postsynthetic modification with respect to the reaction time. They are shown in Fig. 3. The elemental analysis regarding the contents (wt.%) of zinc, carbon, hydrogen, nitrogen via XRF and EA (Elemental Analyzer) was additionally conducted to verify the validity of these yields presented in Fig. 3 (Table S2) and affirmed to achieve significantly reasonable postsynthetic modification of HCC-1s. Furthermore, successful postsynthetic modification was reconfirmed via additional postsynthetic modification of separately
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ica.2012.04.020. References [1] J.L. Rowsell, O.M. Yaghi, Microporous Mesorous Mater. 73 (2004) 3. [2] M. Eddaoudi, J. Kim, N.L. Rosi, D.T. Vodak, J. Wachter, M. O’Keeffe, O.M. Yaghi, Science 295 (2002) 469; H. Li, M. Eddaoudi, M. O’Keeffe, O.M. Yaghi, Nature 402 (1999) 276. [3] N.L. Rosi, J. Eckert, M. Eddaoudi, D.T. Vodak, J. Kim, M. O’Keeffe, O.M. Yaghi, Science 300 (2003) 1127. [4] J. Gascon, U. Aktay, M.D. Hernandez-Alonso, G.P.M. van Klink, F. Kapteijn, J. Catal. 261 (2009) 75. [5] H. Frost, T. Duren, R.Q. Surr, J. Phys. Chem. B. 110 (2006) 9565. [6] M.A. Miller, C.Y. Wang, G.N. Merrill, J. Phys. Chem. C 113 (2009) 3222. [7] A.R. Millward, O.M. Yaghi, J. Am. Chem. Soc. 127 (2005) 17998. [8] Y.S. Bae, D. Dubbeldam, A. Nelson, K.S. Walton, J.T. Hupp, R.Q. Snurr, Chem. Mater. 21 (2009) 4768. [9] Z. Wang, S.M. Cohen, J. Am. Chem. Soc. 129 (2007) 12368. [10] K.K. Tanabe, Z. Wang, S.M. Cohen, J. Am. Chem. Soc. 130 (2008) 8508. [11] Z. Wang, S.M. Cohen, Angew. Chem. Int. Ed. (2008) 4699. [12] Z. Wang, K.K. Tanabe, S.M. Cohen, Inorg. Chem. 48 (2009) 296. [13] Karen L. Mulfort, Omar K. Farha, Charlotte L. Stern, Amy A. Sarjeant, Joseph T. Hupp, J. Am. Chem. Soc. 131 (2009) 3866.
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25 [14] C.J. Doonan, W. Morris, H. Furukawa, O.M. Yaghi, J. Am. Chem. Soc. 131 (2009) 9492. [15] D.O. Kim, J. Park, G.R. Ahn, H.J. Jeon, J.S. Kim, D.W. Kim, M.S. Jung, S.H. Shin, Inorg. Chim. Acta 370 (2011) 76–81. [16] S.-D. Mun, So. H. Kim, J. Lee, H.-J. Kim, Y. Do, Y. Kim, Polyhedron 29 (2010) 379–383.
[17] [18] [19] [20] [21]
C. Morton, Synthetic Page (2001) 180. H. Gilman, W.E. Catlin, Organic Syntheses 1 (1941) 59. U. Zucchini, E. Albizatti, U. Gianni, J. Organomet. Chem. 26 (1971) 357. A. Röder, K.-H. Thiele, J. Organomet. Chem. 199 (1980) C31. D.F. Lindow, R.G. Harvey, J. Am. Chem. Soc. 28 (1971) 3787.
25
Contents lists available at SciVerse ScienceDirect
Inorganica Chimica Acta journal homepage: www.elsevier.com/locate/ica
Note
High-yield postsynthetic modification of MOF with organic–metal precursors Jongsik Kim ⇑,1, Dong Ok Kim 1, Dong Wook Kim, Jeasung Park, Mi Sun Jung Hanwha Chemical Research & Development Center, 6, Shinseong-dong, Yuseong-gu, Daejeon 305-804, Republic of Korea
a r t i c l e
i n f o
Article history: Received 4 January 2012 Received in revised form 8 April 2012 Accepted 12 April 2012 Available online 21 April 2012 Keywords: Postsynthetic modification Metal–organic framework Organic–metal precursor BET Isopropoxytitanatrane Tetrabenzyl titanium
a b s t r a c t The specific yield of postsynthetic modification for modified IRMOF-16 (HCC-1), synthesized using 1,4di(4-carboxy-2-hydroxyphenyl)benzene as organic ligand and Zn(NO3)26H2O as metal source, respectively, has been investigated with the variation of its BET surface area, reaction time and organic–metal precursor. Two kinds of HCC-1 having different values of BET surface area (HCC-1H: 3000 m2/g and HCC-1L: 2000 m2/g) were prepared via solvothermal method for the study of effect of BET surface area, whereas isopropoxytitanatrane and tetrabenzyl titanium were adopted as organic–metal precursors It was observed that even if the specific yields of postsynthetic modification for both organic–metal precursors increased with the value of BET surface area of HCC-1, isopropoxytitanatrane showed relatively higher values than those of tetrabenzyl titanium during the entire range of reaction. These observations led us to conclude that HCC-1H has higher specific number of –OH groups, active sites for postsynthetic modification, and tetrabenzyl titanium experiences more difficulty in diffusing deep into HCC-1 due to its relatively larger molecular size. For the effect of reaction time, while it increased slowly with the reaction time until 48 h and then leveled off for HCC-1H, it increased during the entire range of reaction time for HCC-1L. Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved.
1. Introduction MOFs, having a variety of structures and properties, have been intensively synthesized and studied throughout the world since Yaghi’s group synthesized MOF-5 and reported its structure in the late 1990s [1]. Since it usually consists of two main parts, linker (organic ligand) and node (metal cluster), numerous kinds of MOFs having different structures and properties can be generated simply by changing the combination of these two parts. Furthermore, more precise control of either their pores sizes or shapes is also possible through the molecule-based designs of linker (organic ligand) and node (metal cluster), and it makes them more competitive novel materials than other porous materials such as silica, zeolites and hyper cross-linked polymer particles [2–8]. However, while deepening our knowledge of MOFs, it was suggested that postsynthetic modification of MOF could be far more efficient way to provide MOFs with a variety of functionalities and novel physical properties compared to painstaking jobs, design and synthesis of new MOFs. Thus, some frontier researchers showed successful postsynthetic modifications of MOFs which were applicable to the various fields [9–14]. However, because aforementioned MOFs had relatively smallsized pores, effective postsynthetic modification, especially with ⇑ Corresponding author. Tel.: +82 10 2084 6666; fax: +82 42 865 6570. 1
E-mail address: [email protected] (J. Kim). Contributed equally to this work.
chemical reagents having large and bulky molecular structure, was difficult. Furthermore, since they simply reported the yield of postsynthetic modification instead of the specific yield of postsynthetic modification (the calculated yield of postsynthetic modification based on the perfect-structured MOF), it was difficult to speculate how much additional postsynthetic modification could be achieved if MOFs having more ordered structure were adopted. It is needless to say that the power for characteristic function of postsynthetic modified MOFs is dependent on the specific number of active site.
2. Experimental and results On the basis of above previous researches, we fully understood the importance of postsynthetic modification technology of MOFs and started systematic research. As a first step, a homologous series of p-terphenyl-4,40 -dicarboxylic acid having hydroxyl side groups, ranging from 0 to 4, as functional groups has been synthesized for linkers. Then the first modified IRMOF-16 (HCC-1) has been successfully synthesized via solvothermal method using one of above linkers, 1,4-di(4-carboxy-2-hydroxyphenyl)benzene, as organic ligand and Zn(NO3)26H2O as metal source respectively [15]. Thus HCC-1, having cubic structure with each axis of 21.45 Å, provided us with an opportunity to start more systematic investigation of the postsynthetic modification. In this communication we present the highlights of our findings during the postsynthetic modification
0020-1693/$ - see front matter Crown Copyright Ó 2012 Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.ica.2012.04.020
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25
of HCC-1 with organic–metal precursors, isopropoxytitanatrane [16] and tetrabenzyl titanium [17–21]. The methodical investigation about the postsynthetic modification of HCC-1 germane to its specific yield could be accomplished only after fulfilling two prerequisites, namely, adjusting the number of exposed active site (accessible hydroxyl functional group) of HCC-1 and minimizing the contents of impurities to possibly block the HCC-1’s pores. In terms of meeting these prerequisites, two kinds of HCC-1 samples having different values of BET surface area, 2000 m2/g (HCC-1L) and 3000 m2/g (HCC-1H) were strategically synthesized by applying different synthetic methods (Fig. S2). The difference of BET surface areas between two HCC1s would be owing to the degree of removal upon unreacted organic ligand, undesirably formed oligomeric compounds of that, and reaction solvent (DMF). Specifically, the decantation of reaction mixtures was commonly applied to the synthesis of these MOFs as the first activation step. Furthermore, being delineated in our previous journal [15], CO2 supercritical drying method (SCD) was proved to be undeniably efficient for the elimination of abovementioned impurities in HCC-1’s pores. As a result, this process was adopted as the third activation step for HCC-1H, and the second one for HCC-1L, respectively. On top of that, in the event of the facile preparation of HCC-1H, it is a renowned fact that DMF has a high tendency to generate bonding with the hydrogen atom of hydroxyl functional group presented in HCC-1’s pore via hydrogen bonding mechanism. As a result, with a view to minimizing the chance to form this bonding, conventional solvent exchange method to substitute DMF for chloroform was conducted in the second activation step. Moreover, the chloroform, relatively possessing higher solubility in the supercritical CO2 phase (mimic to the liquid pentane) as well as higher capability to solve the first two of aforementioned impurities than those of DMF, enabled these impurities to be removed more prom-
23
inently. As the final activation step to be followed by carrying out the SCD process, additional vacuum drying (180 °C for 6 h) was executed for the purpose of completely eliminating the trace amount of chloroform (boiling point: 61.2 °C) effectively. For reference, the systematic approach relevant to the maximization of BET surface area for the HCC-1 and its optimization is ongoing. Postsynthetic modifications of HCC-1s with isopropoxytitanatrane and tetrabenzyl titanium have been performed as shown in Fig. 1. Detailed procedures and conditions for measuring BET values, synthesizing MOF and postsynthetic modification are summarized in supporting information. Furthermore, it is worth while noting at this point that CO2 supercritical drying process had been performed after every postsynthetic modification to make sure of the complete elimination of reaction medium solvent and unreacted organic–metal precursors from the MOF complex. Fig. 2 shows the variations of surface morphologies and X-ray diffraction (XRD) patterns of HCC-1 with postsynthetic modifications. It was observed that the surface morphology of HCC-1 remained more or less unchanged but the peak intensity of XRD decreased considerably for both organic–metal precursors. However, any change in XRD pattern suggesting the formation of new phase was not observed. Similar observation, the decline in XRD peak intensity without structural collapse, has been also widely reported in previous researches and regarded as one of good signs for successful postsynthetic modification [9–14]. Another good sign was observed in the analysis of BET surface areas for the prepared samples in that the values of these areas decreased remarkably and consistently after conducting postsynthetic modification of HCC-1s (Table S1). These phenomena were also reported to be a generally acceptable evidence for the successful postsynthetic modification of MOF [9–14]. Besides, as shown in Fig. S7, N2 isotherms, which ultimately evaluate the pore volume and pore size, of the prepared samples typically revealed
Fig. 1. Schematic presentation of postsynthetic modification of HCC-1.
24
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25
Fig. 2. Variations of SEM image and X-ray diffraction pattern after postsynthetic modification of (a) HCC-1H with (b) isopropoxytitanatrane and (c) tetrabenzyl titanium for 48 h.
synthesized IRMOF-16, having the same molecular structure as HCC-1 but no functional group, with tetracyclohexyl titanium. In this case, no Ti was observed, and it was clear enough for us to conclude that hydroxyl group of HCC-1 was a sole reaction site for postsynthetic modification with tetracyclohexyl titanium. The specific yields of HCC-1H (circles) showed much higher values compared with those of HCC-1L (rectangles) during the entire range of reaction time for both organic–metal precursors. As explained in supporting information, it is speculated that higher specific yields of HCC-1H are caused by the fact that the accessible specific number of hydroxyl functional groups (sole reaction site for postsynthetic modification) is proportional to the value of BET surface area. Besides BET effect, the effect of molecular structure of organic– metal precursor on the yield of postsynthetic modification was also clearly observed. In other words, the levels of specific yield for tetrabenzyl titanium were much lower compared with those of isopropoxytitanatrane regardless of BET values. It’s not difficult to imagine that relatively larger and bulkier molecular structure of tetrabenzyl titanium made its diffusion depth into HCC-1 relatively shallow and caused lower specific yield. Moreover, the increases of specific yields with BET value at given reaction times for tetrabenzyl titanium were much smaller than those of isopropoxytitanatrane, and this drove us to suppose one more thing that even if accessible specific number of functional side group increases, it’s rather difficult to obtain higher specific yield of postsynthetic modification in case of bulky structured organic–metal precursor. 3. Conclusions In summary, the value of BET surface area and molecular structure of organic–metal precursor were proven to be very important factors for obtaining higher yield of postsynthetic modification because the accessible specific number of hydroxyl functional side groups in HCC-1 was found to be proportional to its BET value and smaller size of organic–metal precursor was more desirable for effective diffusion into HCC-1. Based on the results of experiments, it was confirmed that HCC-1 complex having more than 8 wt.% of Ti, metalation at an atomic level, was successfully synthesized via postsynthetic modification. This result will be a very important and meaningful step for the application of postsynthetic modification technology to the chemical reaction catalyst, special purpose membrane, selective gas absorption material and etc. Appendix A. Supplementary material
Fig. 3. The variations of specific yield of postsynthetic modification of HCC-1 with reaction time and organic–metal precursors [isopropoxytitanatrane (solid lines) and tetrabenzyl titanium (dotted lines)].
type-I behavior indicating a steep increase in adsorption at P/ P0 0.0 owing to the rapid filling of nitrogen in the well-defined micropores as well as no significant hysteresis. In addition to observations made by SEM and XRD, the elemental analysis of Ti via X-ray fluorescence (XRF), was performed in an effort to observe the variations of specific yield of postsynthetic modification with respect to the reaction time. They are shown in Fig. 3. The elemental analysis regarding the contents (wt.%) of zinc, carbon, hydrogen, nitrogen via XRF and EA (Elemental Analyzer) was additionally conducted to verify the validity of these yields presented in Fig. 3 (Table S2) and affirmed to achieve significantly reasonable postsynthetic modification of HCC-1s. Furthermore, successful postsynthetic modification was reconfirmed via additional postsynthetic modification of separately
Supplementary data associated with this article can be found, in the online version, at http://dx.doi.org/10.1016/j.ica.2012.04.020. References [1] J.L. Rowsell, O.M. Yaghi, Microporous Mesorous Mater. 73 (2004) 3. [2] M. Eddaoudi, J. Kim, N.L. Rosi, D.T. Vodak, J. Wachter, M. O’Keeffe, O.M. Yaghi, Science 295 (2002) 469; H. Li, M. Eddaoudi, M. O’Keeffe, O.M. Yaghi, Nature 402 (1999) 276. [3] N.L. Rosi, J. Eckert, M. Eddaoudi, D.T. Vodak, J. Kim, M. O’Keeffe, O.M. Yaghi, Science 300 (2003) 1127. [4] J. Gascon, U. Aktay, M.D. Hernandez-Alonso, G.P.M. van Klink, F. Kapteijn, J. Catal. 261 (2009) 75. [5] H. Frost, T. Duren, R.Q. Surr, J. Phys. Chem. B. 110 (2006) 9565. [6] M.A. Miller, C.Y. Wang, G.N. Merrill, J. Phys. Chem. C 113 (2009) 3222. [7] A.R. Millward, O.M. Yaghi, J. Am. Chem. Soc. 127 (2005) 17998. [8] Y.S. Bae, D. Dubbeldam, A. Nelson, K.S. Walton, J.T. Hupp, R.Q. Snurr, Chem. Mater. 21 (2009) 4768. [9] Z. Wang, S.M. Cohen, J. Am. Chem. Soc. 129 (2007) 12368. [10] K.K. Tanabe, Z. Wang, S.M. Cohen, J. Am. Chem. Soc. 130 (2008) 8508. [11] Z. Wang, S.M. Cohen, Angew. Chem. Int. Ed. (2008) 4699. [12] Z. Wang, K.K. Tanabe, S.M. Cohen, Inorg. Chem. 48 (2009) 296. [13] Karen L. Mulfort, Omar K. Farha, Charlotte L. Stern, Amy A. Sarjeant, Joseph T. Hupp, J. Am. Chem. Soc. 131 (2009) 3866.
J. Kim et al. / Inorganica Chimica Acta 390 (2012) 22–25 [14] C.J. Doonan, W. Morris, H. Furukawa, O.M. Yaghi, J. Am. Chem. Soc. 131 (2009) 9492. [15] D.O. Kim, J. Park, G.R. Ahn, H.J. Jeon, J.S. Kim, D.W. Kim, M.S. Jung, S.H. Shin, Inorg. Chim. Acta 370 (2011) 76–81. [16] S.-D. Mun, So. H. Kim, J. Lee, H.-J. Kim, Y. Do, Y. Kim, Polyhedron 29 (2010) 379–383.
[17] [18] [19] [20] [21]
C. Morton, Synthetic Page (2001) 180. H. Gilman, W.E. Catlin, Organic Syntheses 1 (1941) 59. U. Zucchini, E. Albizatti, U. Gianni, J. Organomet. Chem. 26 (1971) 357. A. Röder, K.-H. Thiele, J. Organomet. Chem. 199 (1980) C31. D.F. Lindow, R.G. Harvey, J. Am. Chem. Soc. 28 (1971) 3787.
25