20 Angstroem Cd4In16S3514- Supertetrahedral T4 Clusters as Building Units in Decorated Cristobalite Frameworks

Full text of DOI:10.1021/ja010413f

J. Am. Chem. Soc. 2001, 123, 4867-4868
4867
0 Å Cd4In16S351 Supertetrahedral T4 Clusters as
4-
2
Building Units in Decorated Cristobalite Frameworks
†
†
‡
,‡
Hailian Li, Jaheon Kim, T. L. Groy, M. O’Keeffe,* and
O. M. Yaghi*,†
Materials Design and DiscoVery Group
Department of Chemistry, UniVersity of Michigan
Ann Arbor, Michigan 48109-1055
Department of Chemistry, Arizona State UniVersity
Tempe, Arizona 85287-1604
ReceiVed February 16, 2001
The process of replacing a vertex in a network by a group of
vertexesstermed decorationshas been recognized as an important
strategy for designing low-density (porous) metal-organic frame-
1
works. We and others have recently employed this strategy in
the synthesis of inorganic frameworks based on TX
4
(T1)
tetrahedra by using Tn supertetrahedral clusters in which n
2
,3
tetrahedra are linked along each edge as illustrated in Figure 1.
4-
10-
10-
Ge
have been linked into the cristobalite framework of SiO
on a diamond network), in which SiO tetrahedra are replaced
4
S10 (T2) and In10
S
20
and B10
S
20
(T3) supertetrahedra
2
(Si atoms
4
by T2 or T3 clusters to produce large-pore structures. However,
structures with larger Tn supertetrahedral units remain unknown,4
although they have the potential of creating novel low-density
nanoporous crystalline solids as well as yielding ordered and
regular arrays of clusters that are comparable in size to individual
nanocrystallites of tetrahedral quantum dots of CdS and other
Figure 1. Construction of supertetrahedra from a single tetrahedron (T1,
MX ) shown in progression of size from T2 (M X ) to T3 (M X ) to
4
4
10
10 20
T4 (M X ). Here M is a metal cation and X is anion such as sulfide.
20
35
4,5
group 12 chalcogenides. Here we report the preparation of T4
clusters of 20 Å dimension6 in a Cd
In16
S
33
10-
cristobalite
4
(0.50 mL, 2.43 mmol) at 145 °C in a Teflon-lined vessel for 4
days. This phase is insoluble in water and organic polar and
nonpolar solvents.
2
+
framework, and discuss the essential role Cd plays in facilitating
the realization of such structures.
7
Yellow octahedral crystals of Cd
hereafter CdInS-44) were prepared by reacting a water (1.0 mL)
and ethylene glycol (0.5 mL) solution mixture of In (65.0 mg,
.57 mmol), S (45.0 mg, 1.40 mmol), Cd(CH CO ‚2H O (40.0
mg, 0.15 mmol), and 1,4-bis(3-aminopropyl)piperazine (BAPP)
4
In16
S
33‚(H
2
O)20(C10H
28
N
4
)
2.5
A single-crystal X-ray diffraction study on CdInS-44 showed
(
that its structure is composed of two intergrown networks each
constructed from T4 units that are linked together by doubly
0
3
2
)
2
2
bridging sulfide atoms to produce a cristobalite (SiO ) topology:
2
each T4 supertetrahedron decorates the vertexes occupied by Si
and the sulfides bridging the T4 units replace the -O- links
(Figure 2a). Each T4 supertetrahedron is nearly regular with edge
lengths (S‚‚‚S distances) of 15.69 and 15.85 Å. However, since
the T-S-T angle (106.9 (3)°) is significantly less than the typical
T-O-T angle (145° in cristobalite), the resulting network is
*
To whom correspondence should be addressed.
University of Michigan.
†
‡
Arizona State University.
(1) (a) O’Keeffe, M.; Eddaoudi, M.; Li, H.; Reineke, T.; Yaghi, O. M. J.
Solid State Chem. 2000, 152, 3-20. (b) Li, H.; Eddaoudi, M.; O’Keeffe, M.;
Yaghi, O. M. Nature 1999, 402, 276-279. (c) Eddaoudi, M.; Moler, D. B.;
Li, H.; Chen, B.; O’Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2001, 34,
relatively contracted. As In3 and Cd are isoelectronic they
+
2+
3
19−330.
2) (a) Yaghi, O. M.; Sun, Z.; Richardson, D. A.; Groy, T. L. J. Am. Chem.
cannot be distinguished directly by X-ray diffraction; however,
(
8
the Cd/In ratio was determined by elemental microanalysis and
Soc. 1994, 116, 807-808. (b) Bowes, C. L.; Lough, A. j.; Malek, A.; Ozin,
G. A.; Petrov, S.; Young, D. Chem. Ber. 1996, 129, 283-287. (c) Cahill, C.
L.; Parise, J. B. Chem. Mater. 1997, 9, 807-811.
verified by analysis of the bond lengths. The bonds to S from
the inner metal sites in each T4 range from 2.502(2) to 2.516(7)
Å (average 2.507(4) Å), which can be compared with the Cd-S
distance of 2.525 Å in the sphalerite structure of CdS and 2.55 Å
(3) (a) Hammerschmidt, A.; zum Hebel, P.; Hiltmann, F.; Krebs, B. Z.
Anorg. Allg. Chem. 1996, 622, 76-884. (b) Cahill. C. L.; Ko, Y.; Parise, J.
B. Chem. Mater. 1998, 10, 10-19. (c) Cahill, C. L.; Parise, J. B. J. Chem.
Soc., Dalton Trans. 2000, 1475-1482 and references therein. (d) Li, H.; Laine,
A.; O’Keeffe, M.; Yaghi, O. M. Science 1999, 283, 1145-1147. (e) Li, H.;
Eddaouddi, M.; Laine, A.; O’Keeffe, M.; Yaghi, O. M. J. Am. Chem. Soc.
1
(7) Single crystals of CdInS-44 are, at 298°K, tetragonal, space group I4 /
3
acd with a ) 23.580 (8) Å, c ) 43.92 (1) Å, V ) 24422 (14) Å , and Z ) 16
-3
1
999, 121, 6096-6097.
formula units {based on CdInS framework, dcalcd ) 1.825 g cm ; µ (Mo KR)
a
-1
(4) Isolated Cd, S and Cd, Se clusters close to the T4 and T5 geometries
) 4.264 mm }. A total of 15484 integrated reflection intensities having 2Θ-
(Mo KR) < 49.96° were produced using the Bruker program SAINT version
6.02A. A total of 5027 of these were independent and gave Rint ) 0.1102. All
have been reported: (a) Herron, N.; Calabrese, J. C.; Farneth, W. W.; Wang,
Y. Science 1993, 259, 1426-1428. (b) Soloviev, V. N.; Eichh o¨ fer, A.; Fenske,
D.; Banin, U. J. Am. Chem. Soc. 2001, 123, 2354-2364.
stages of weighted full-matrix least-squares refinement were conducted using
2
(5) (a) Alivisatos, A. P. Science 1996, 271, 933-937. Recent work which
F
o
data with the SHELXTL-97 software package and converged to give R
1
2
gives additional references includes: (b) Empedocles, S.; Bawendi, M. Acc.
Chem. Res. 1999, 32, 389-396. (c) Banin, U.; Cao, Y.; Katz, D.; Milo, O.
Nature 1999, 400, 542-544. (d) Klimov, V. I.; Mikhailovsky, A. A.; Xu, S.;
Malko, A.; Hollingsworth, J. A.; Leatherdale, C. A.; Eisler, H.-J.; Bawendi,
M, Science 2000, 290, 314-317. (e) Wise, F. W. Acc. Chem. Res. 2000, 33,
(unweighted, based on F) ) 0.1138, wR (weighted, based on F ) ) 0.2664,
2
and goodness of fit (S) ) 1.114. Sulfur and indium were refined with
anisotropic displacement parameters. All metal positions were refined as
indium atoms. Although water and BAPP cation molecules were not included
in the model due to major disorder problems and diffuse electron density, the
residual electron density indicates their presence in the pores. However,
attempts to include the guests in the model did not improve the refinement.
7
73-780. (f) Peng, X.; Manna, L.; Yang, W.; Wickham, J.; Scher, E.;
Kadavanich, A.; Alivistos, A. P. Nature 2000, 404, 59-61. (g) Huang, X.;
Li, J. J. Am. Chem. Soc. 2000, 122, 8789-8790. (h) Soloviev, V. N.; Eichh o¨ fer,
A.; Fenske, D.; Banin, U. J. Am. Chem. Soc. 2000, 122, 2673-2674.
(8) (a) Anal. Calcd for CdInS-44 or Cd
4
In16
S
2 28 4
33‚(H O)20(C10H N )2.5: C,
7.12; H, 2.63; N, 3.32; S, 25.09; Cd, 10.67; In, 43.58. Found: C, 7.10; H,
2.49; N, 3.37; S, 24.61; Cd, 10.56; In, 42.60. (b) FT-IR (KBr, BAPP range,
1500-700 cm- ): 1466.2 (m), 1150.3 (b), 1005.5 (w), 755.4 (s).
(
6) The van der Waals radius of S (1.80 Å) was employed in the
1
determination of sizes. Bondi, A. J. Phys. Chem. 1964, 68, 441-451.
1
0.1021/ja010413f CCC: $20.00 © 2001 American Chemical Society
Published on Web 04/28/2001

4868 J. Am. Chem. Soc., Vol. 123, No. 20, 2001
Communications to the Editor
for n < 4). In the limit of large n the structure approaches that of
sphalerite ZnS, and in this limit the T atoms must be divalent as
the whole (neutral) crystal is one giant cluster. We suppose that
in accord with Pauling’s electrostatic valence rule, or better, in
accordance with Brown’s equal valence rule,10 the 4-coordinated
divalent X atoms (e.g. S atoms) will be bonded only to divalent
tetrahedral (T) atoms (such as Cd) so that each of these X atoms
forms four bonds with bond valence 1/2. For this to be the case
the number of trivalent T atoms will be 6n - 8, and the number
of divalent atoms is accordingly t - 6n + 8, thus progressively
n
larger Tn supertetrahedra will have an increasing ratio of divalent
to trivalent cation and the charge per cluster remains negative
(Table 1). Note that the hypothesis that the four-connected S atoms
in CdInS-44 are bonded to Cd is confirmed both by the chemical
analysis and by the bond length analysis given above.
Figure 2. The crystal structure of CdInS-44 containing two interpenetrat-
ing cristobalite-like networks (a) (blue and red) and large channels shown
in the [111] projection (b).
Despite being contracted and 2-fold intergrown (interpene-
trated), the structure of CdInS-44 contains large cavities: in
2
particular there are 20 × 6 Å rectangular channels in the [111]
6
Table 1. Composition and Charge per Supertetrahedon for
projection (Figure 2b). Although the positions of the framework
Condensed Supertetrahedral Structuresa
atoms were determined accurately, the guest atoms filling the
pores were not located due to the disorder problems usually
encountered in this kind of structure. Nevertheless, elemental
microanalysis and FTIR confirmed the presence of 20 water and
S coordination
binary
ternary
composition charge composition charge
4
3
2
T1
T2
T3
T4
T5
T6
T7
T8
InS
In
In10
In20
In35
In56
In84
2
-1
0
0
0
1
4
10
20
35
0
0
4
12
24
40
60
84
2
2
.5 BAPP guests for each T4 cluster or 160 water and 20 BAPP
4
S
8
S
S
S
S
S
-4
8
14
20
26
32
38
44
7,8
molecules per unit cell. These guests fill a calculated non-
framework void space that is 53% of the crystal volume.
18
33
54
82
118
-6
-6 Cd
-3 Cd13In22
+4 Cd28In28
+16 Cd50In34
+34 Cd80In40
6
,11
4
In16
S
S
S
S
S
33
-10
-16
-24
-34
-46
Thermal gravimetric measurements on CdInS-44 showed two
major weight loss steps in two temperature ranges indicating the
removal of guests from the voids: (a) 8.4% between 23 and 180
°C associated with the removal of 20 water molecules per formula
unit (calcd: 8.5%), and (b) 14.0% between 230 and 430 °C
attributed to the decomposition of 2.5 BAPP guests (calcd:
54
82
118
163
In120S
163
a
Cd and In are used generically for divalent and trivalent cations,
and S for a divalent anion.
1
2.1%) and the loss of 1.9% of S. At 600 °C, this material is
converted to CdIn and In as evidenced by X-ray powder
diffraction. In contrast to the behavior of the T3 analogue (ASU-
S
2 4
2 3
S
9
expected from bond valence parameters. For the remaining sites,
the T-S bond lengths are significantly shorter: 2.403(6)-2.487-
3e
3
4), preliminary attempts to exchange BAPP guests with small
(
7) Å (average 2.451(6) Å), a value that is typical for a tetrahedral
inorganic cations by exposing solids of CdInS-44 to concentrated
solutions of simple inorganic salts showed very little to no
exchange. We believe that the rectangular nature of the void
openings hinder the facile diffusion of large guests such as BAPP
from the structure.
9
In-S bond length (2.47 Å).
The number of tetrahedra (T atoms) in a Tn supertetrahedron
is the nth tetrahedral number t ) n(n + 1)(n + 2)/6. The number
n
of distinct vertexes (X atoms) in one supertetrahedron is tn+1. In
a continuous framework, each of the four outermost vertexes of
a supertetrahedron is shared with another supertetrahedron so the
Acknowledgment. Dedicated to Professor G. F e´ rey on the occasion
of his 60th birthday. The National Science Foundation support to M.O.’K
overall composition is T
x
X
y
with x ) t
n
and y ) tn+1 - 2. Table
1
lists compositions for some small values of n and also the formal
(DMR-9804817), O.M.Y. (CHE-9702131), and ASU in the form of an
charge per cluster assuming T is trivalent (e.g. B or In) and X is
divalent (e.g. S). Notice that the charge changes sign between
T5 and T6. However, as we next discuss, we feel it is less likely
that binary clusters larger than T3 will be stable for trivalent
cations, and that the use of divalent ions such as Cd2 is essential
in accessing larger clusters.
instrument grant for single crystal diffraction (CHE-9808440) is gratefully
acknowledged.
Supporting Information Available: Crystallographic data, bond
lengths, and angles for CdInS-44 (PDF). This material is available free
of charge via the Internet at http://pubs.acs.org.
+
Although all the T atoms are 4-coordinated, the X atoms have
JA010413F
2
-coordination (on the supertetrahedron edges and the outermost
vertexes), 3-coordination (in the supertetrahedron faces), and
-coordination (inside the cluster). Per Tn cluster in a corner-
linked framework, the number of 2-coordinated S atoms is 6n -
, the number of 3-coordinated S atoms is 2(n - 1)(n - 2) and
when n ) 4, the number of 4-coordinated S atoms is tn-3 (zero
(
10) (a) Brown, I. D. Acta Crystallogr. B 1977, 37, 1305-1310. (b) For
4
the implications of Brown’s equal valence rule see: O’Keeffe, M. In Modern
PerspectiVes in Inorganic Crystal Chemistry; Parth e´ , E., Ed.; Kluwer:
Dordrecht, The Netherlands, 1992.
4
(11) Cerius2.0 was used to calculate the volume occupied by interpenetrat-
ing frameworks which is then subtracted from the crystal volume to give the
total volume of voids. Crevices below 1.0 Å in diameter were included in the
space occupied by the frameworks and thus not included in the void volume.
(9) Brese, N. E.; O’Keeffe, M. Acta Crystallogr. B 1991, 47, 192-197.