Oxozinc carboxylate complexes: A new synthetic approach and the carboxylate ligand effect on the noncovalent-interactions-driven self-assembly

Article abstract of DOI:10.1021/ic300864n

An atom-efficient and mild synthesis of a series of oxozinc carboxylates [Zn₄(μ₄-O)(O₂CR)₆] [where R = Ph (2a), p-PhC₆H₄ (2b), p-MeC₆H₄ (2c), and p-MeSC₆H₄ (2d)] from well-defined alkylzinc precursors and H₂O is described. The molecular and crystal structures of the resulting complexes have been determined by single-crystal X-ray diffraction. A closer examination of their crystal structure provides a direct picture of the effect of the nature of substituents on the molecular self-assembly of the octahedral oxozinc through noncovalent interactions. It was revealed that these discrete oxozinc clusters can form diverse types of noncovalent assemblies ranging from structures representing zeolitic topologies in the case of 2a to soft porous materials with gated voids or open channels for the remaining molecular clusters.

Full text of DOI:10.1021/ic300864n

Article
pubs.acs.org/IC
Oxozinc Carboxylate Complexes: A New Synthetic Approach and the
Carboxylate Ligand Effect on the Noncovalent-Interactions-Driven
Self-Assembly
Wojciech Bury,† Iwona Justyniak,*,‡ Daniel Prochowicz,† Anna Rola-Noworyta,‡ and Janusz Lewinski*,†,‡
́
†Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
‡Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland
S
* Supporting Information
ABSTRACT: An atom-efficient and mild synthesis of a series of oxozinc carboxylates [Zn4(μ4-O)(O2CR)6] [where R = Ph (2a),
p-PhC6H4 (2b), p-MeC6H4 (2c), and p-MeSC6H4 (2d)] from well-defined alkylzinc precursors and H2O is described. The
molecular and crystal structures of the resulting complexes have been determined by single-crystal X-ray diffraction. A closer
examination of their crystal structure provides a direct picture of the effect of the nature of substituents on the molecular self-
assembly of the octahedral oxozinc through noncovalent interactions. It was revealed that these discrete oxozinc clusters can form
diverse types of noncovalent assemblies ranging from structures representing zeolitic topologies in the case of 2a to soft porous
materials with gated voids or open channels for the remaining molecular clusters.
al. reported the [Zn4(μ4-O)(O2CCp*)6] formed by the direct
carboxylation reaction of zincocene Cp*2Zn with CO2.11
Herein we describe a novel effective and mild methodology
for the synthesis of a series of oxozinc carboxylates involving
well-defined alkylzinc precursors and H2O. The subsequent
study provides a direct picture of the influence of the
substituent on the carboxylate ligand in generation of
supramolecular architectures. Our structural analysis revealed
that these discrete oxozinc clusters can form diverse types of
noncovalent porous materials ranging from structures repre-
senting zeolitic topologies to soft porous materials with gated
voids or open channels.
Alkylzinc carboxylates still represent an insufficiently ex-
plored family of organozinc compounds. Our group6 and
others12 demonstrated that these complexes form various
discrete polynuclear assemblies depending on the character of
both the zinc-bonded substituents and the carboxylate ligands.
In our search for effective synthetic methods of various metal
oxide aggregates,6,13 and encouraged by our recent results on
the hydrolysis of zinc alkyls,14 we designed and developed the
following two-step reaction system for the atom-efficient
preparation of [Zn4(μ4-O)(O2CR)6]-type clusters, involving
commercially available Et2Zn, a carboxylic acid, and H2O. In
addition, the study was extended to examination of the
INTRODUCTION
■
Zinc oxocarboxylates have been widely utilized as basic building
units in a large class of microporous zinc-based metal−organic
frameworks (MOFs).1 Typically isoreticular MOF-type struc-
tures can be synthesized via solvothermal reaction of inorganic
zinc salts with dicarboxylic acids. Recently oxozinc cluster was
also applied as a very efficient predefined precursor for the
synthesis of MOF-5 under mild conditions.2 The [Zn4O]6+
nodal regions within these materials, which are of particular
interest as promising hydrogen storage materials,3 have been
identified as the principal sites for the adsorption of a hydrogen
molecule.4 In addition, the potential capability of molecular
oxozinc clusters for hydrogen adsorption was previously
demonstrated by Redshaw et al.5 Surprisingly, issues concern-
ing the self-assembly process of oxozinc carboxylate clusters as
well as the carboxylate ligand effect on this process have been
rarely reported in the literature.5,6 A variety of related oxozinc
clusters supported by different organic ligands, like carbox-
ylates,5−7 carbamates,8 amides,9 or phosphonates,10 have been
prepared. However, lack of efficient and rational synthetic
strategies leading to well-defined oxozinc complexes results in
characterization of the products formed accidentally, and not as
a consequence of a rational design. For instance, we reported
on the synthesis of [Zn4(μ4-O)(O2CPh)6] through oxidation of
the corresponding zinc carboxylate with dry oxygen,6 whereas
Redshaw et al. obtained an oxocarboxylate complex by reaction
of Zn(C6F5)2 with 3-dimethylaminobenzoic acid in the
presence of trace amounts of water.5 More recently, Schulz et
Received: April 30, 2012
Published: June 8, 2012
© 2012 American Chemical Society
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noncovalent-interactions-driven self-assembly processes of the
resulting series of oxozinc carboxylates.
isolated at 4 °C in an almost quantitative yield. Encouraged by
this result we extended our atom-efficient approach to the
synthesis of a number of oxozinc clusters supported by other
benzoic acid derivatives. We selected 4-methylbenzoic acid, 4-
(methylthio)benzoic acid, and 4-biphenylcarboxylic acid as
starting reagents in order to test the effect of substituents in
position 4 on the noncovalent-driven self-assembly processes of
the resulting oxozinc carboxylates.
RESULTS AND DISCUSSION
■
An Atom-Efficient Synthetic Method of Oxozinc
Carboxylates. In a control experiment we added 2 mol
equiv of Et2Zn to 3 mol equiv of benzoic acid in THF, which
resulted in the quantitative formation of a novel alkylzinc
carboxylate [{EtZn(O2CPh)}{Zn(O2CPh)2}·THF] (1)
(Scheme 1).
A similar two-step synthetic procedure involving 2 equiv of
Et2Zn in THF and 3 equiv of the selected carboxylic acid (for
the selection criterion vide infra) and followed by the addition
of 0.5 equiv of H2O yielded a series of isostructural oxozinc
clusters [Zn4(μ4-O)(O2CR)6] [where R = p-PhC6H4 (2b), p-
MeC6H4 (2c), and p-MeSC6H4 (2d)]. Compounds 2b−d were
isolated in high yields as cubic crystals, and the identity of the
oxozinc carboxylates has been confirmed by X-ray crystallog-
raphy (for experimental and crystallographic details see
Experimental Section and Supporting Information). The
identity of 2a was confirmed by X-ray crystallography and
proved to be consistent with the previous reports.6 The
structural analysis of 2b−d revealed the presence of
isostructural monomeric oxo-centered tetranuclear units with
corresponding six μ-1,2-carboxylate bridges. In all cases, the
central oxozinc core remained essentially unchanged, with the
Zn−Ooxo bond lengths falling into the range of 1.923−1.954 Å.
However, the crystal structure analysis of these compounds
provides interesting observations concerning the effect of the
substituents’ nature on the molecular self-assembly process of
octahedral oxozinc clusters. It is noticeable that the
corresponding geometric parameters in 2a−d are very similar
to those observed in the reported single crystal structure of
MOF-5 (Table 1S, Supporting Information).15
Scheme 1
Compound 1 was isolated by crystallization from the
postreaction mixture, and its structure was determined by
spectral and X-ray single crystal studies. It crystallizes in a
triclinic space group P1 as a dinuclear cluster that can be
̅
formally treated as an adduct of ethylzinc benzoate [EtZn-
(O2CPh)] and zinc dibenzoate [Zn(O2CPh)2] species. In the
molecular structure of 1, three carboxylate groups bridge two
zinc atoms, nicely resembling a paddle-wheel motif with three
puckered eight-membered Zn2O4C2 rings (Figure 1). The
Investigations on the Supramolecular Structures of
2a−d. A detailed analysis of the crystal structure of 2a revealed
that the Zn4O clusters self-assemble through complementary
specific noncovalent interactions to produce an extended 3D
network with open-gated voids. From a topological point of
view, the supramolecular structure of 2a resembles that
observed in the natural zeolite analcite (ANA) (NaAl-
Si2O6·H2O) (Figure 2a). On the basis of PLATON calculations,
Figure 1. Molecular structure of 1; hydrogen atoms have been omitted
for clarity. Selected bond lengths (Å) and angles (deg): Zn1−O3,
2.017(9); Zn1−O4, 2.024(3); Zn1−O6, 2.045(1); Zn2−O1,
2.026(7); Zn2−O2, 1.944(1); Zn2−O5, 1.916(3); O4−Zn1−O3,
106.2(4); O4−Zn1−O6, 101.3(8); O1−Zn2−O2, 96.1(1); O2−Zn2−
O5, 115.5(1).
Figure 2. (a) Topological representation of 2a. (b) Crystal packing
structure for 2a along the a axis and the solvent accessible areas; sky
blue and navy blue represent the interior and exterior pore surface,
respectively.
metal centers represent a distorted tetrahedral coordination
environment where Zn−O bond lengths fall within a range of
1.916−2.045 Å. It should be noted that 1 represents a new
example of an alkylzinc carboxylate family, exhibiting vast
structural variety.12
In the next step we carried out the reaction between 1 and
H2O in a molar ratio of 2:1 and in THF solution at ambient
temperature for 12 h. From the postreaction mixture colorless
icosahedral-shaped crystals of [Zn4(μ4-O)(O2CPh)6] (2a) were
the accessible free voids in 2a are estimated to be about 39.3%
of the unit cell volume; however, these cages were inaccessible
for gas molecules because of very small aperture sizes (vide
infra), which is characteristic for analcite topology (Figure
2b).16
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Figure 3. (a) Molecular structure of 2b. (b) View of the supramolecular arrangement in a 2D grid of 2b along the b axis. The purple lines represent
C−Har···π cooperative interactions. Hydrogen atoms are omitted, excluding those involved in the nonconvalent interaction. (c) Crystal packing
structure for 2b along the c axis and the solvent accessible areas. (d) Molecular structure of 2d. (e) View of the 2D zigzag-like network in the crystal
structure of 2d along the a axis showing the intermolecular CHar···S hydrogen bonds and CHar···π interactions (purple lines). (f) Crystal packing
structure for 2d along the a axis and the solvent accessible areas.
The observed 3D open framework structure with zeolite-like
topology for 2a encouraged us to employ the phenyl-
substituted analogue of 2a. We anticipated that the extension
of the aromatic linkage may lead to significant changes in the
molecular self-assembly of the oxozinc complex by increasing
the spacing between vertices in a net and yielding an extended
void space. Indeed, a closer examination of the structure of 2b
revealed that the Zn4O clusters self-assemble via C−Har···π
cooperative interactions to produce 2D grids with open
channels directed along the b axis with diameter of ∼8 Å
(Figure 3b). Unfortunately, these 2D grids are further
organized by weak π···π stacking interactions into an extended
3D network featuring partially close packing of empty spaces in
the crystal lattice (Figure 3c). PLATON calculation indicates
an accessible volume of 23.4% upon solvent removal.
We also investigated the effect of methyl and methylthio
substituents in the para-position of the carboxylate ligand on
the supramolecular structure evolution and explored whether it
could be used for further modification of the packing mode of
the resulting noncovalent materials. A detailed analysis of the
crystal structure of 2c shows that hierarchical self-organization
steps of these units driven by combination of noncovalent
interactions lead to the formation of a 3D supramolecular
network. The first level self-assembly process comprises the
docking of four parent molecules of 2c, which are held together
by cooperative C−Har···O hydrogen bonds formed by aromatic
hydrogen and carboxylate-oxygen atoms (with the distance of
2.718(6) Å), which results in the formation of the non-
covalently bonded supertetrahedral cage, as illustrated in Figure
4a. These “secondary building modules” are further organized
through a subsequent self-assembly process induced by C−
Har···π interactions into an extended layered close-packed 3D
structure with gated voids (Figure 4d). On the basis of
PLATON calculations, the free voids in 2c are estimated to
constitute 31.3% of the unit cell volume; however, these voids
are inaccessible due to the lack of connecting channels between
them.
Upon the introduction of a donor atom to the substituent in
the phenyl ring of 2d, we expected further complications in the
resulting supramolecular architecture as the sulfur atom can be
involved in intra- and intermolecular noncovalent interactions.
Indeed, adjacent molecular moieties of 2d are interconnected
by the intermolecular CHar···S hydrogen bonds between the
sulfur and the hydrogen atoms of the aromatic ring (with the
distance of 2.952 Å), leading to the H-bonded zigzag-like chain,
as depicted in Figure 3e. Additionally, a network of
intermolecular complementary CHar···π interactions resulted
in the formation of 2D double layers lying on the (100)
crystallographic plane. Thus, in the presence of the S−Me
substituent, noncovalent interactions lead to the formation of
the 2D framework with the existence of zigzag-like channels
constituting 34% potential guest-accessible volume of the
crystal volume based on the PLATON calculation (Figure 3f).
The degree of permanent porosity of 2a−d was further
verified by gas sorption measurements. In all cases attempts to
evaluate an N2 adsorption isotherm at 77 K revealed no
significant uptake up to 1 bar, indicating the presence of gated
voids in the host framework that blocks diffusion of N2
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commercial vendors. Solvents were dried and distilled prior to use.
Redistilled water was degassed carefully by six freeze−pump−thaw
cycles before use. NMR spectra were acquired on Varian Mercury 400
spectrometer.
Synthesis of 1. Et2Zn (0.246 g, 2.00 mmol) was added to a
suspension of benzoic acid (0.366 g, 3.00 mmol) in THF (10 mL) at
−78 °C and then the reaction mixture was allowed to warm to 20 °C.
Colorless plate crystals were obtained after crystallization from THF/
1
toluene mixture at 20 °C; isolated yield ca. 89%. H NMR (CDCl3,
400.10 MHz, 298 K): δ = 0.19 (q, 2H; ZnCH2CH3), 1.08 (t, 3H;
ZnCH2CH3), 1.89 (m, 4H; CH2-THF), 3.86 (m, 4H; OCH2-THF),
7.39 (m, 6H; Ar), 7.513 (m, 3H; Ar), 8.16 ppm (m, 6H; Ar). Anal.
Calcd for C27H28O7Zn2: C, 54.52; H, 4.71. Found: C, 55.12; H, 4.97.
Synthesis of 2b. Et2Zn (0.492 g, 4.00 mmol) was added to a
suspension of 4-biphenylcarboxylic acid (1.19 g, 6.00 mmol) in THF
(10 mL) at −78 °C. After 4 h, degassed H2O (18 μL, 1.00 mmol) was
added, and the solution was stirred for an additional 20 h. Colorless
cubic crystals were isolated from a CH2Cl2 solution at −20 °C;
1
isolated yield ca. 85%. H NMR (CDCl3, 400.10 MHz, 298 K): δ =
7.45−8.13 ppm (m, 54H; Ar). Anal. Calcd for C78H54O13Zn4: C,
64.14; H, 3.69. Found: C, 64.30; H, 3.87.
Synthesis of 2c. A similar procedure as for 2b using p-toluic acid
(0.810 g, 6.00 mmol) in THF and Et2Zn (0.492 g, 4.00 mmol) in THF
was used. All volatile compounds were removed under vacuum, and
white powder was obtained. Colorless cubic crystals were isolated
upon recrystallization from a THF solution at −20 °C; isolated yield
Figure 4. (a) View of the supertetrahedral cage of 2c as a building
module in the construction of extended 3D structure along the a axis;
the purple lines represent C−Har···O cooperative interactions.
Hydrogen atoms are omitted, excluding those involved in the
nonconvalent interaction. (b) Crystal packing structure for 2c along
the a axis and the solvent accessible areas. (c) Topological
representation of 2c. (d) View of the extended 3D network in the
crystal structure of 2c.
1
ca. 89%. H NMR (CDCl3, 400.10 MHz, 298 K): δ = 2.38 (s, 3H;
CH3), 7.32 (m, 2H; Ar), 8.12 ppm (m, 2H; Ar). Anal. Calcd for
C48H42O13Zn4: C, 52.98; H, 3.86. Found: C, 53.30; H, 3.97.
Synthesis of 2d. A similar procedure as for 2b using 4-
(methylthio)benzoic acid (1.01 g, 6.00 mmol) and Et2Zn (0.492 g,
4.00 mmol) in THF was used. Yellow cubic crystals were isolated by
crystallization from a THF solution at −20 °C; isolated yield ca. 87%.
1H NMR (CDCl3, 400.10 MHz, 298 K): δ = 2.40 (s, 3H; SCH3), 7.28
(m, 2H; Ar), 7.94 ppm (m, 2H; Ar). Anal. Calcd for C48H42O13S6Zn4:
C, 45.02; H, 3.28; S, 15.02. Found: C, 45.35; H, 3.42; S, 14.87.
Crystallographic Data. The data were collected at 100(2) K on a
Nonius Kappa CCD diffractometer18 using graphite-monochromated
Mo Kα radiation (λ = 0.710 73 Å). The unit cell parameters were
determined from ten frames and then refined on all data. The data
were processed with DENZO and SCALEPACK (HKL2000 pack-
age).19 The structure was solved by direct methods using the
SHELXS9720 program and was refined by full-matrix least−squares on
F2 using the program SHELXL97.21 All non-hydrogen atoms were
refined with anisotropic displacement parameters. The hydrogen
atoms were introduced at geometrically idealized coordinates with a
fixed isotropic displacement parameter equal to 1.5 (methyl groups)
times the value of the equivalent isotropic displacement parameter of
the parent carbon. Crystallographic data (excluding structure factors)
for the structures reported in this paper have been deposited with the
Cambridge Crystallographic Data Centre as supplementary publication
no. CCDC-830646 (1), CCDC-878003 (2b), CCDC-830647 (2c),
CCDC-830648 (2d). Copies of the data can be obtained free of charge
on application to CCDC, 12 Union Road, Cambridge CB21EZ, UK
[fax: (+44)1223−336−033; e-mail: deposit@ccdc.cam.ac.uk].
molecules across the channel network;17 however, the CO2
adsorption studies for 2a and 2b at 273 K showed noticeable
CO2 uptakes of 10 cm3 g−1 (1.8 and 2.1 wt %, respectively) at
STP (Figure S5, Supporting Information). On the basis of the
nonlocal density functional theory (NLDFT) method, the
calculated surface areas for 2a and 2b were 90 and 95 m2/g,
respectively. Thus only a portion of available void spaces in the
crystal lattice is available for gas molecules. The results indicate
that the limiting pore diameter for these materials is higher than
the kinetic diameter of CO2, which may be due to structure
collapse during activation process or to the need to apply a
more efficient activation procedure.
CONCLUSIONS
■
In conclusion, we have developed a novel atom-efficient
methodology for the synthesis of oxozinc carboxylates and a
series of complexes [Zn4(μ4-O)(O2CR)6] [where R = p-
MeC6H4 (2b), p-PhC6H4 (2c), p-MeC6H4 (2d)] was prepared
and crystallographically characterized. We hope that this
approach can be added as a convenient tool in the synthesis
of well-defined oxozinc complexes. Our study revealed that
these discrete clusters form diverse types of noncovalent
assemblies, driven by the type of substituent in the aromatic
ring, possessing void spaces or open channels. Further studies
on the utilization of oxozinc carboxylates with purposefully
functionalized carboxylate ligands as effective molecular
building blocks for the construction of noncovalent porous
materials are in progress.
1: C27H28O7Zn2, M = 595.27, crystal dimensions 0.48 × 0.35 × 0.25
mm3, triclinic, space group P1 (No. 2), a = 9.9271(5) Å, b =
̅
10.8259(4) Å c = 12.4851(7) Å, α = 97.652(3)°, β = 101.911(2)°, γ =
95.374(3)°, U = 1291.00(11) Å3, Z = 2, F(000) = 612, Dc = 1.531 g
m3, T = 100(2)K, μ(Mo Kα) = 1.902 mm−1, Nonius Kappa-CCD
diffractometer, θmax = 25.68°, 4820 unique reflections. Refinement
converged at R1 = 0.0397, wR2 = 0.0698 for all data and 326
parameters [R1 = 0.0332, wR2 = 0.0673 for 4316 reflections with Io >
2σ(Io)]. The goodness-of-fit on F2 was equal to 1.082. A weighting
2
2
scheme w = [σ2(Fo + (0.0418P)2 + 3.1964P]−1 where P = (Fo
+
2Fc2)/3 was used in the final stage of refinement. The residual electron
density = +0.35/−0.42 e Å−3
EXPERIMENTAL SECTION
All manipulations were conducted under a nitrogen atmosphere by
using standard Schlenk techniques. All reagents were purchased from
2b: C78H54O13Zn4·2CH2Cl2, M = 1630.63, crystal dimensions 0.44
× 0.32 × 0.26 mm3, monoclinic, space group P21/c (No. 14), a =
20.7641(8) Å, b = 14.8559(4) Å c = 25.5201(9) Å, β = 102.0510(10)°,
■
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U = 7698.7(5) Å3, Z = 4, F(000) = 3320, Dc = 1.407 g m3, T =
100(2)K, μ(Mo Kα) = 1.430 mm−1, Nonius Kappa-CCD diffrac-
tometer, θmax = 22.46°, 9871 unique reflections. Refinement converged
at R1 = 0.0940, wR2 = 0.1644 for all data and 910 parameters [R1 =
0.0552, wR2 = 0.1310 for 7190 reflections with Io > 2σ(Io)]. The
goodness-of-fit on F2 was equal to 1.061. A weighting scheme w =
[σ2(Fo2 + (0.0418P)2 + 3.1964P]−1 where P = (Fo2 + 2Fc2)/3 was used
in the final stage of refinement. The residual electron density = +0.73/
−0.87 e Å−3.
Eckert, J.; Yaghi, O. M. J. Am. Chem. Soc. 2005, 127, 14904−14910.
(c) Spencer, E. C.; Howard, J. A. K.; McIntyre, G. J.; Rowsell, J. L. C.;
Yaghi, O. M. Chem. Commun. 2006, 278−280.
(5) Redshaw, C.; Jana, S.; Shang, C.; Elsegood, M. R. J.; Lu, X.; Guo,
Z. X. Organometallics 2010, 29, 6129−6132.
́
(6) Lewinski, J.; Bury, W.; Dutkiewicz, M.; Maurin, M.; Justyniak, I.;
Lipkowski, J. Angew. Chem., Int. Ed. 2008, 47, 573−576.
(7) (a) Hiltunen, L.; Leskela, M.; Makela, M.; Niinisto, L. Acta Chem.
Scand. A 1987, 41, 548−550. (b) Clegg, W.; Harbron, D. R.; Homan,
C. D.; Hunt, P. A.; Little, I. R.; Straughan, B. P. Inorg. Chim. Acta 1991,
186, 51−60. (c) Yin, M. C.; Wang, C. W.; Sun, J. T. Chin. J. Lumin.
2c: C48H42O13Zn4, M = 1088.38, crystal dimensions 0.44 × 0.36 ×
0.30 mm3, cubic, space group I23/c (No. 197), a = 23.034(5) Å, U =
12221(5) Å3, Z = 8, F(000) = 4432, Dc = 1.183 g m3, T = 100(2)K,
2003, 24, 485−488. (d) Otvos, S. B.; Berkesi, O.; Kortvel
́
yesi, T.;
̈
̈
μ(Mo Kα) = 1.600 mm−1, Nonius Kappa-CCD diffractometer, θmax
=
Pal
́
inko,
́
I. Inorg. Chem. 2010, 49, 4620−4625.
27.93°, 4751 unique reflections. Refinement converged at R1 = 0.0677,
wR2 = 0.1189 for all data and 199 parameters (R1 = 0.0474, wR2 =
0.1116 for 3728 reflections with Io > 2σ(Io)). The goodness-of-fit on
F2 was equal to 1.102. A weighting scheme w = [σ2(Fo2 + (0.0418P)2 +
(8) McCowan, C. S.; Groy, T. L.; Caudle, M. T. Inorg. Chem. 2002,
41, 1120−1127.
(9) Davies, R. P.; Linton, D. J.; Schooler, P.; Snaith, R.; Wheatley, A.
E. H. Chem.Eur. J. 2001, 7, 3696−3704.
2
3.1964P]−1 where P = (Fo + 2Fc2)/3 was used in the final stage of
(10) Yang, Y.; Pinkas, J.; Noltemeyer, M.; Schmidt, H.−G.; Roesky,
H. W. Angew. Chem., Int. Ed. 1999, 38, 664−666.
refinement. The residual electron density = +0.46/−0.39 e Å−3.
2d: C48H42O13S6Zn4, M = 1280.31, crystal dimensions 0.44 × 0.38
× 0.34 mm3, monoclinic, space group P21/c (No. 14), a = 14.1301(8)
Å, b = 16.5959(5) Å, c = 30.8969(16) Å, β = 101.998(2)°, U =
7087.1(6) Å3, Z = 4, F(000) = 2600, Dc = 1.200 g m3, T = 100(2)K,
(11) Schulz, S.; Schmidt, S.; Blaser, D.; Wolper, C. Eur. J. Inorg.
̈
̈
Chem. 2011, 27, 4157−4160.
(12) (a) Dickie, D. A.; Jennings, M. C.; Jenkins, H. A.; Clyburne, J. A.
C. Inorg. Chem. 2005, 44, 828−830. (b) Redshaw, C.; Elsegood, M. R.
Angew. Chem., Int. Ed. 2007, 46, 7453−7457. (c) Orchard, K. L.;
White, A. J. P.; Shaffer, M. S. P.; Williams, C. K. Organometallics 2009,
28, 5828−5832. (d) Redshaw, C.; Elsegood, M. R. J.; Frese, J. W. A.;
Ashby, S.; Chao, Y.; Mueller, A. Chem. Commun. 2012, DOI: 10.1039/
c2cc32060f. (e) Orchard, K. L.; Harris, J. E.; White, A. J. P.; Shaffer, M.
S. P.; Williams, C. K. Organometallics 2011, 30, 2223−2229.
μ(Mo Kα) = 1.560 mm−1, Nonius Kappa-CCD diffractometer, θmax
=
23.25°, 9890 unique reflections. Refinement converged at R1 = 0.0952,
wR2 = 0.1409 for all data and 646 parameters (R1 = 0.0577, wR2 =
0.1298 for 6095 reflections with Io > 2σ(Io)). The goodness-of-fit on
F2 was equal to 0.931. A weighting scheme w = [σ2(Fo2 + (0.0418P)2 +
2
3.1964P]−1 where P = (Fo + 2Fc2)/3 was used in the final stage of
refinement. The residual electron density = +0.77/−0.57 e Å−3.
(13) Al oxo clusters: (a) Lewin
Lipkowski, J. Angew. Chem., Int. Ed. 2006, 45, 2872−2875. (b) Bury,
W.; Chwojnowska, E.; Justyniak, I.; Lewinski, J.; Affek, A.; Zygadło-
Monikowska, E.; Bąk, J.; Florjanczyk, Z. Inorg. Chem. 2012, 51, 737−
745. Zn oxo clusters: (c) Lewinski, J.; Suwała, K.; Kaczorowski, T.;
Gałęzowski, M.; Gryko, D. T.; Justyniak, I.; Lipkowski, J. Chem.
́
ski, J.; Bury, W.; Justyniak, I.;
ASSOCIATED CONTENT
* Supporting Information
́
■
́
S
́
X-ray crystallographic files in CIF format, molecular figures, and
bond length/bond angle tables for compounds 1a and 2b−d.
This material is available free of charge via the Internet at
http://pubs.acs.org.
́
Commun. 2009, 215−217. (d) Sokołowski, K.; Justyniak, I.; Sliwin
W.; Sołtys, K.; Tulewicz, A.; Kornowicz, A.; Lipkowski, J.; Moszynski,
R.; Lewin
ski, J. Chem.Eur. J. 2012, 18, 5637−5645. (e) Zelga, K.;
Leszczynski, M.; Justyniak, I.; Kornowicz, A.; Cabaj, M.; Wheatley, A.
E. H.; Lewinski, J. Dalton Trans. 2012, 41, 5934−5938.
(14) Bury, W.; Krajewska, E.; Dutkiewicz, M.; Sokołowski, K.;
́
ski,
́
́
́
AUTHOR INFORMATION
Corresponding Author
*E-mail: lewin@ch.pw.edu.pl.
́
■
Justyniak, I.; Kaszkur, Z.; Kurzydłowski, K. J.; Płocin
Chem. Commun. 2011, 19, 5467−5469.
́ ́
ski, T.; Lewinski, J.
Notes
(15) Eddaoudi, M.; Kim, J.; Rosi, N.; Vodak, D.; Wachter, J.;
O’Keeffe, M.; Yaghi, O. M. Science 2002, 295, 469−472.
(16) For the Database of Zeolite Structures, please see: www.iza-
structure.org/databases/.
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
(17) We note that the structures have not collapsed during the
adsorption, as indicated by PXRD measurements of the bulk materials.
(18) KappaCCD Software; Nonius B.V.: Delft, The Netherlands,
1998.
The authors would like to acknowledge the Ministry of Science
and Higher Education: projects N N204 142237 (W.B.) and N
N204 164336 and the European Union in the framework
through the Warsaw University of Technology Development
Programme of ESF (D.P.) for financial support.
(19) Otwinowski, Z.; Minor, W. Methods Enzymol. 1997, 276, 307.
(20) Sheldrick, G. M. Acta Crystallogr., Sect. A 1990, 467−473.
(21) Sheldrick, G. M. SHELXL97; University Gottingen, Germany,
̈
1997.
REFERENCES
■
(1) (a) Li, H.; Eddaoudi, M.; O’Keeffe, M.; Yaghi, O. M. Nature
1999, 402, 276−279. (b) Eddaoudi, M.; Moler, D. B.; Li, H.; Chen, B.;
Reineke, T. M.; O’Keeffe, M.; Yaghi, O. M. Acc. Chem. Res. 2001, 34,
319−330.
(2) Hausdorf, S.; Baitalow, F.; Boehle, T.; Rafaja, D.; Mertens, F. O.
R. L. J. Am. Chem. Soc. 2010, 132, 10978−10981.
(3) For selected examples see: (a) Rosi, N. L.; Eckert, J.; Eddaoudi,
M.; Vodak, D. T.; Kim, J.; O’Keeffe, M.; Yaghi, O. M. Science 2003,
300, 1127−1129. (b) Rowsell, J. L. C.; Yaghi, O. M. Angew. Chem., Int.
́
Ed. 2005, 44, 4670−4679. (c) Ferey, G. Chem. Soc. Rev. 2008, 37,
191−214. (d) Suh, M. P.; Park, H. J.; Prasad, T. K.; Lim, D.-W. Chem.
Rev. 2012, 112, 782−835.
(4) (a) Rowsell, J. L. C.; Spencer, E. C.; Eckert, J.; Howard, J. A. K.;
Yaghi, O. M. Science 2005, 309, 1350−1354. (b) Rowsell, J. L. C.;
7414
dx.doi.org/10.1021/ic300864n | Inorg. Chem. 2012, 51, 7410−7414