measurement),2 but was comparable to that of MOF5
(B4400 m2 gꢀ1).8
R1 (wR2)
R1(wR2) = 0.1228 (0.1846) for all 3375 reflections.
y The IR spectrum of 2a (Fig. S7w) indicates the presence of some
carboxylic acid in the activated sample. We could not succeed in removing
this carboxylic acid from the framework even though the sample was
extensively washed and/or soaked using various organic solvents.
= 0.0944 (0.1721) for 2860 reflections [I 4 2s(I)],
The H2 uptake of PMOF-2(Cu) obtained using a volumetric
sorption measurement method was 2.29 wt% at 77 K and
1 atm. The isosteric heat of adsorption of PMOF-2(Cu) was
calculated using a modified version of the Clausius–Clapeyron
equation by fitting a second H2 adsorption isotherm at 87 K
(Fig. S6a and S6bw).9 The initial isosteric heat of adsorption
at 0.02 wt% H2 loading on 2a, 9.2 kJ molꢀ1, decreased to
5.0 kJ molꢀ1 at a loading of 1.46 wt% H2. This range of the
isosteric heat of adsorption was similar to other MOFs having
1 (a) R. E. Morris and P. S. Wheatley, Angew. Chem., Int. Ed., 2008,
47, 4966–4981; (b) G. Ferey, Chem. Soc. Rev., 2008, 37, 191–214;
´
(c) M. Eddaoudi, D. B. Moler, H. Li, B. Chen, T. M. Reineke,
M. O’Keeffe and O. M. Yaghi, Acc. Chem. Res., 2001, 34, 319–330;
(d) F. A. Cotton, C. Lin and C. A. Murillo, Acc. Chem. Res., 2001,
34, 759–771; (e) O. M. Yaghi, M. O’Keeffe, N. W. Ockwig,
H. K. Chae, M. Eddaoudi and J. Kim, Nature, 2003, 423,
705–714; (f) S. S.-Y. Chui, S. M.-F. Lo, J. P. H. Charmant,
A. G. Orpen and I. D. Williams, Science, 1999, 283, 1148–1150;
exposed metal sites in similar Cu(II) paddle-wheel units.10
A
high-pressure H2 sorption study was performed on 2a using
the volumetric measurement method. The inset of Fig. 3 shows
the excess and total H2 adsorption isotherms at 77 K. The
excess gravimetric H2 adsorption capacity of 2a reached its
maximum value of 5.0 wt% around 30 bar and the total
gravimetric H2 uptake was 7.0 wt% at 50 bar, values that were
smaller than those of MOF-5 with a similar surface area. The
corresponding total volumetric H2 uptake of 2a, 39.2 g Lꢀ1, is
also smaller than that of MOF-5. This reduced efficiency of
PMOF-2(Cu) for H2 uptake might come from the large average
cavity diameter of the MOF11 and/or the incomplete removal of
the non-reacted or partially reacted reactants in the pores.y
In conclusion, we prepared two isostructural MOFs based
on covalently interconnected metal–organic cuboctahedra.
Although the structural elements resembled one another, the
stability and sorption behaviors of the MOFs were completely
different. The framework of PMOF-2(Zn) was not stable when
the sample was activated. When the solvents in the cavity were
removed, its N2 sorption and the corresponding surface area
were very small, probably because of the collapse of the cavity
caused by the instability of the Zn(II) paddle-wheel secondary
building unit. In contrast, the framework of PMOF-2(Cu) was
stable up to 250 1C. The N2 sorption study of the activated
sample of PMOF-2(Cu) revealed extremely large BET and
Langmuir surface areas, B3730 and B4180 m2 gꢀ1, respectively.
The framework with exposed metal sites was thermally and
hygroscopically stable and showed high adsorption enthalpy.
PMOF-2(Cu) is a new type of MOF having very interesting H2
sorption properties. Further studies on the sorption behaviors
of this MOF are currently in progress.
(g) H. K. Chae, D. Y. Siberio-Perez, J. Kim, Y. Go, M. Eddaoudi,
´
A. J. Matzger, M. O’Keeffe and O. M. Yaghi, Nature, 2004, 427,
523–527; (h) H. Li, A. Laine, M. O’Keeffe and O. M. Yaghi,
Science, 1999, 283, 1145–1147; (i) G. Fe
C. Serre, F. Millange, J. Dutour, S. Surble
Science, 2005, 309, 2040–2042.
´
rey, C. Mellot-Draznieks,
´
and I. Margiolaki,
2 (a) H. Furukawa, M. A. Miller and O. M. Yaghi, J. Mater. Chem.,
2007, 17, 3197–3204; (b) A. G. Wong-Foy, A. J. Matzger and
O. M. Yaghi, J. Am. Chem. Soc., 2006, 128, 3494–3495.
3 (a) D. J. Collins and H.-C. Zhou, J. Mater. Chem., 2007, 17,
3154–3160; (b) M. Dinca, A. Dailly, Y. Liu, C. M. Brown,
D. A. Neumann and J. R. Long, J. Am. Chem. Soc., 2006, 128,
16876–16876; (c) J. L. C. Rowsell and O. M. Yaghi, Angew. Chem.,
Int. Ed., 2005, 44, 4670–4679; (d) M. Latroche, S. Surble
C. Mellot-Draznieks, P. L. Llewellyn, J.-H. Lee, J.-S. Chang,
S. H. Jhung and G. Ferey, Angew. Chem., Int. Ed., 2006, 45,
´
, C. Serre,
´
8227–8231; (e) J. L. C. Rowsell and O. M. Yaghi, J. Am. Chem.
Soc., 2006, 128, 1304–1315.
4 (a) J. Park, S. Hong, D. Moon, M. Park, K. Lee, S. Kang, Y. Zou,
R. P. John, G. H. Kim and M. S. Lah, Inorg. Chem., 2007, 46,
10208–10213; (b) H. Chun, J. Am. Chem. Soc., 2008, 130, 800–801.
5 (a) F. Nouar, J. F. Eubank, T. Bousquet, L. Wojtas,
M. J. Zaworotko and M. Eddaoudi, J. Am. Chem. Soc., 2008,
130, 1833–1835; (b) Y. Wang, P. Cheng, Y. Song, D.-Z. Liao and
S.-P. Yan, Chem.–Eur. J., 2007, 13, 8131–8138.
6 (a) J. J. Perry IV, V. Ch. Kravtsov, G. J. McManus and
M. J. Zaworotko, J. Am. Chem. Soc., 2007, 129, 10076–10077;
(b) A. J. Cairns, J. A. Perman, L. Wojtas, V. Ch. Kravtsov,
M. H. Alkordi, M. Eddaoudi and M. J. Zaworotko, J. Am. Chem.
Soc., 2008, 130, 1560–1561; (c) X.-S. Wang, S. Ma, K. Rauch,
J. M. Simmons, D. Yuan, X. Wang, T. Yildirim, W. C. Cole,
J. J. Lo
20, 3145–3152; (d) X.-S. Wang, S. Ma, P. M. Foster, D. Yuan,
J. Eckert, J. J. Lopez, B. J. Murphy, J. B. Parise and H.-C. Zhou,
´
pez, A. D. Meijere and H.-C. Zhou, Chem. Mater., 2008,
´
Angew. Chem., Int. Ed., 2008, 47, 7263–7266; (e) Y. Lee,
H. R. Moon, Y. E. Cheon and M. P. Suh, Angew. Chem., Int. Ed.,
2008, 47, 7741–7745; (f) Y. Yan, X. Lin, S. Yang, A. J. Blake,
A. Dailly, N. R. Champness, P. Hubberstey and M. Schroder, Chem.
Commun., 2009, 1025–1027.
7 Y. Zou, M. Park, S. Hong and M. S. Lah, Chem. Commun., 2008,
2340–2342.
8 S. S. Kaye, A. Dailly, O. M. Yaghi and J. R. Long, J. Am. Chem.
Soc., 2007, 129, 14176–14177.
9 (a) F. Roquerol, J. Rouquerol and K. Sing, in Adsorption by
Powders and Porous Solids: Principles, Methodology,
and Applications, Academic Press, London, 1999, pp. 32–36;
(b) S. Sircar, R. Mohr, C. Ristic and M. B. Rao, J. Phys. Chem. B,
1999, 103, 6539–6546.
10 (a) M. Dinca and J. R. Long, Angew. Chem., Int. Ed., 2008, 47,
6766–6779; (b) J. G. Vitillo, L. Regli, S. Chavan, G. Ricchiardi,
G. Spoto, P. D. C. Dietzel, S. Bordiga and A. Zecchina, J. Am.
Chem. Soc., 2008, 130, 8386–8396.
This work was supported by KRF (KRF-2008-
313-C00424), KOSEF (R01-2009-0052888) and CBMH.
The KRICT researchers are grateful to ISTK through the
Institutional Research Program (KK-0904-A0) for the
financial support. The authors also acknowledge PAL for
beam line use (2009-1063-06).
Notes and references
z Crystal data for 1: Zn24C288H144O120: M = 7092.91, cubic, space
3
group Fm3m, a = 42.854(5), V = 78 699(16) A , T = 100(2) K,
ꢀ
Z
=
4, m(synchrotron,
l
=
0.77489 A)
=
0.752 mmꢀ1
,
147 398 reflections were collected of which 4347 were unique
(Rint = 0.0576). R1 (wR2) = 0.0653 (0.2344) for 3890 reflections
[I 4 2s(I)], R1 (wR2) = 0.0699 (0.2434) for all 4347 reflections.
11 (a) J. L. C. Rowsell and O. M. Yaghi, Angew. Chem., Int. Ed.,
2005, 44, 4670–4679; (b) J. L. Belof, A. C. Stem, M. Eddaoudi and
B. Space, J. Am. Chem. Soc., 2007, 129, 15202–15210; (c) M. Dinca
and J. R. Long, J. Am. Chem. Soc., 2005, 127, 9376–9377;
(d) S. Ma, J. Eckert, P. M. Forster, J. W. Yoon, Y. K. Hwang,
J.-S. Chang, C. D. Collier, J. B. Parise and H.-C. Zhou, J. Am.
Chem. Soc., 2008, 130, 15896–15902.
Crystal data for 2: Cu24C288H144O120: M = 7048.99, cubic, space
3
group Fm3m, a = 42.833(3) A, V = 78 583(10) A , T = 173(2) K,
ꢀ
Z
=
4, m(Mo-Ka,
l = 0.71073 A) = , 95 044
0.670 mmꢀ1
reflections were collected of which 3375 were unique (Rint = 0.1675).
ꢂc
This journal is The Royal Society of Chemistry 2009
Chem. Commun., 2009, 5397–5399 | 5399