Tuning the catalytic activity of lanthanide-organic framework for the cyanosilylation of aldehydes

Article abstract of DOI:10.1016/j.molcata.2013.07.016

Lanthanide-organic framework (LnMOF) [Eu₂(MELL)(H ₂O)₆] (1) was rapidly produced via microwave-assisted hydrothermal synthesis and its performance as heterogeneous catalyst for the cyanosilylation of aldehydes was investig

Full text of DOI:10.1016/j.molcata.2013.07.016

Journal of Molecular Catalysis A: Chemical 379 (2013) 68–71
Contents lists available at ScienceDirect
Journal of Molecular Catalysis A: Chemical
journal homepage: www.elsevier.com/locate/molcata
Tuning the catalytic activity of lanthanide-organic framework for
the cyanosilylation of aldehydes
a
a
b
c
Poliane K. Batista , Danilo J.M. Alves , Marcelo O. Rodrigues , Gilberto F. de Sá ,
c
a,∗
Severino A. Junior , Juliana A. Vale
a
Departamento de Química, UFPB, 58051-900 Joao Pessoa, PB, Brazil
Instituto de Química, Universidade de Brasília, 70904-970 Brasília, DF, Brazil
Departamento de Química Fundamental, UFPE, 50590-470 Recife, PE, Brazil
b
c
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 27 June 2012
Received in revised form 23 July 2013
Accepted 28 July 2013
Available online 12 August 2013
Lanthanide-organic framework (LnMOF) [Eu (MELL)(H O) ] (1) was rapidly produced via microwave-
2
2
6
assisted hydrothermal synthesis and its performance as heterogeneous catalyst for the cyanosilylation of
aldehydes was investigated. The catalytic assays were performed with different aldehydes and solvents
◦
using as-prepared and thermally active (100 C for 1 h) LnMOF material, and the results show that (1)
acts as an excellent catalyst for the addition of trimethylsilyl cyanide to aldehydes with short reaction
times and excellent yields. In addition, the catalyst was recycled and recovered in the addition reaction
of TMSCN to 2-furfuraldehyde without loss of activity.
Keywords:
Cyanosilylation of aldehyde
Heterogeneous catalysis
Lanthanide
©
2013 Elsevier B.V. All rights reserved.
Metal-organic framework
MOF
1
. Introduction
[17]. The addition of cyanide to a carbonyl compound to form a
cyanohydrin is one of the fundamental carbon-carbon bond form-
ing reactions in organic chemistry [18]. It is important to note
that the enantioselective synthesis of cyanohydrin represents a
useful route for the production of important organic interme-
diates, such as ␣-hydroxyl acids and their derivatives as well
as ␤-amino alcohols [19]. The most commonly used alternative
cyanide source is trimethylsilyl cyanide (TMSCN). Catalysis with
TMSCN can also be induced thermally or by an enormous range
of catalysts including Lewis acids, bases and nucleophiles [20].
The Lewis acid used for the addition of TMSCN in aldehydes
and ketones primarily includes compounds based on transi-
tion metals [20] including MOFs [21] and lanthanides metal
compounds [15,20,22]. Therefore, lanthanide-organic frameworks
(LnMOFs) exhibit great potential as Lewis acids in heterogeneous
catalysis. While catalysis is one of the most promising applica-
tions of LnMOFs, only a few examples have been reported to
Metal-organic frameworks (MOFs), which are also known as
coordination polymers (CPs), are a class of crystalline compounds
that have been extensively studied in the last twenty years [1].
The worldwide interest is motivated by the almost infinite possi-
bilities for framework construction, wide superficial area, porosity
and potential applications in catalysis [2], luminescence [3], sensor
[
4], magnetism [5], gas storage [6], drug delivery [7] and optoelec-
tronics [8]. MOFs have proved to be very useful in heterogeneous
catalysis, because they combine advantages, such as facile separa-
tion and recovery of the catalyst as well as high stability and ease
of handling [9]. In addition, the MOF pores may be systematically
tailored for specific catalytic applications [10]. These characteris-
tic provide good justification for the growing interest in MOFs as
heterogeneous catalysts in organic reactions [2b,11].
Lanthanide compounds have been extensively used as Lewis
acids in various reactions including asymmetric catalysis. The most
common application appears in homogeneous catalysis with the
use of chloride [12], triflates [13], p-toluenesulfonates [14], dithio-
carbamate complexes [15], alkoxides [16] and others compounds
3+
3+
date. Recently, [Ln (MELL)(H O) ] materials (where Ln = La
,
2
3+
2
6
3+
3+
Eu , Tb
and Gd ) have been synthesized and were used
as light-conversion molecular devices (LCMDs) and a contrast
agent for magnetic resonance imaging (MRI) [23]. However, to
date, investigations of their catalytic activities are non-existent.
Therefore, we report on the performance of [Eu (MELL)(H O) ]
2
2
6
as a heterogeneous catalyst for the cyanosilylation of aldehydes
Scheme 1).
∗ Corresponding author. Tel.: +55 83 2126 7437; fax: +55 83 2126 7437.
E-mail address: julianadqf@yahoo.com.br (J.A. Vale).
(
1
381-1169/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.molcata.2013.07.016

P.K. Batista et al. / Journal of Molecular Catalysis A: Chemical 379 (2013) 68–71
69
OTMS
TMSCN
R
O
0
R
CN
MOF, solvent,25 C
2
Scheme 1.
2
. Experimental
2.1. Synthesis of europium organic-framework
An equimolar mixture (0.85 mmol) of mellitic acid (Mell),
Eu(NO ) ·6H O and H O (4.0 mL) in a 10.0 mL IntelliVent reac-
3
3
2
2
TM
tor was placed inside a CEM Focused Microwave
Synthesis
System Discover S-Class apparatus. The reactions proceeded at
◦
1
80 C over 20 min under constant magnetic stirring. The final
materials were obtained in a yield of ca. 60% after being washed
with water, acetone and air-dried. The powder synchrotron X-
ray diffraction patterns were acquired at ambient temperature
◦
(
300 K) in a 2ꢀ range of 8–25 using a Huber diffractometer
in high resolution mode (low intensity, E = 10 keV) on a multi-
purposed powder station D10A-XRD2 beam line at the Brazilian
Synchrotron Light Laboratory (LNLS). Variable-temperature pow-
der X-ray diffraction data for [Eu (MELL)(H O) ] (1) were collected
2
2
6
using a Bruker D8 Advanced with DaVinci design equipped with
a LynxEye Linear Position Sensitive Detector and a copper (Cu)
Fig. 1. Three-dimensional structure of (1). View along the b-axis.
sealed tube (ꢁk˛ = 1.5404 A˚ , ꢁk˛ = 1.5444 A˚ , I˛ /I˛ = 0.5) fitted
1
2
2
1
with an Anton Parr HKL 16 high-temperature chamber controlled
(
0.125 mmol) followed by TMSCN (0.25 mmol). The resulting solu-
tion was stirred at room temperature for 1 h prior to quenching
with H O (10.0 mL). The mixture was diluted with dichloromethane
by an Anton Parr 100 TCU unit. The sample was submitted at 30,
◦
1
00, 125 and 150 C for a period of 1 h prior to data collection.
2
◦
The intensity data were collected in the step mode (0.02 , 5 per
(
15 mL), the organic phase was isolated, the organic extracts were
◦
step) in the range of ca. 10 ≤ 2ꢀ ≤ 48. The Rietveld refinements
dried over anhydrous Na SO and the solvent was removed in vac-
2
4
[
24] for [Eu (MELL)(H O) ] were performed with the software
2 2 6
uum. When necessary, the crude product was purified via flash
column chromatography (30% ethyl acetate/hexanes as eluent) to
afford the product as an oil. The conversion to the correspond-
ing O-trimethylsilyl ethers cyanohydrins was analyzed by gas
chromatography coupled with a mass spectrometer. All of the
compounds were characterized by comparison with previously
reported spectral data.
GSAS/EXPGUI [25] using the atomic coordinates of the structural
model previously reported as a starting guess [23a]. The pref-
erential orientation was corrected using the spherical harmonic
model (sixth order) proposed by Jarvinen [26], the peak profile was
adjusted using the Thompson-Cox-Hastings function modified by
Young and Desai (pV-TCHZ) [27], the surface roughness correction
was refined using the Pitschke function and the background was
fitted by an eighth-degree shifted Chebyshev polynomial function.
In the final runs, the following parameters were refined: scale fac-
tor, background and absorption coefficients, spherical harmonic,
unit-cell parameters and pV-TCHZ correction for the asymmetric
parameters.
3
. Results and discussion
The [Eu (MELL)(H O) ] structure is basically
a
three-
2
2
6
dimensional framework (Fig. 1) with a one-dimensional channel
system running parallel to the b-axis [19].
◦
Fig. 2 shows the Rietveld refinement for (1) treated at 100 C
2.2. General procedure for cyanosilylation of aldehydes
◦
for 1 h, the variable-temperature powder patterns (125 and 150 C)
and the thermogravimetric curves (TGA/DTG) acquired for the as-
prepared LnMOF material.
◦
[
Eu (MELL)(H O) ] preheated at 100 C for 1 h (10.0 mg) in ace-
2
2
6
tonitrile (3.0 mL) at room temperature was added to the aldehyde
◦
Fig. 2. (a) Final Rietveld plot of [Eu2(MELL)(H2O)6] (1) acquired after thermal treatment (100 C for 1 h). Observed data points are indicated by black circles and the best-fit
profile, difference pattern and Bragg reflections are represented as red and green solid lines and blue vertical bars, respectively. (b) and (c) Powder patterns acquired after
◦
thermal treatments at 125 and 150 C for 1 h; (d) Thermogravimetric curves (TGA/DTG) of [Eu2(MELL)(H2O)6].

7
0
P.K. Batista et al. / Journal of Molecular Catalysis A: Chemical 379 (2013) 68–71
Table 1
Conversions of PhCHO to 2 catalyzed by [Eu2(MELL)(H2O)6].
Table 2
Addition of TMSCN to benzaldehyde catalyzed by activated (1) in various solvents.
Mass (mg)
Time (min)#
Conversion to 2 (%)#
Entry
Solvent
Time (min)
Conversion to 2 (%)#
*
5
180
180
600*
180
180
44
72
1
2
3
4
5
6
Hexane
180
90
100
60
180
180
34
98
95
*
*
5
–
0
0
Methylene chloride
Tetrahydrofuran
Acetonitrile
Ethyl alcohol
Water
**
8***
90
*
*
*
*
100 (45*)
1
3
100
14
0
#
Conditions: PhCHO: TMSCN (1:2) in toluene (5.0 mL at room temperature). The
conversion of PhCHO to 2 was determined by GC analysis relative to dodecane as an
#
The conversion of PhCHO to 2 was determined by GC analysis relative to dode-
internal standard.
cane as an internal standard.
*
*
As-prepared (1).
Using Eu(NO3)3·6H2O as the catalyst.
*
*
(
1) thermally activated.
*
**
Reaction performed without catalyst.
In acetonitrile, an increase in the reaction rate was observed with
complete substrate conversion in 60 min at room temperature. The
yield and reaction time were higher than those obtained using
The Rietveld refinement for [Eu (MELL)(H O) ] after the first
2
2
6
[
Nd(btc)(H O)] [29] as the catalyst and Eu(NO ) ·6H O. Polar pro-
2
3 3
2
thermal treatment (Fig. 2(a)) does not show noticeable modifica-
tions in the powder pattern, which indicated that the prepared
compound retained its structural integrity under this condition.
The TGA/DTG results are in good agreement with the X-ray diffrac-
tion data, because a weight loss event (0.12%) was observed up to
tic solvents, such as water and ethyl alcohol, interfere with the
reaction, because they inhibit the catalyst action by formation of
hydrogen bonds with the substrate [30]. The results showed that
the optimal condition for the cyanation reaction includes 10 mg
of [Eu (MELL)(H O) ] in acetonitrile. Therefore, this condition was
◦
2
2
6
ca. 80 C corresponding to the complete release of uncoordinated
extended to reactions of other aldehydes. The results are summa-
rized in Table 3.
water molecules present on the crystal surface. Unlike the previ-
ously reported LnMOFs, the [Eu (MELL)(H O) ] material exhibits
2
2
6
As observed in Table 3, a wide variety of aldehydes can be
converted to the corresponding O-trimethylsilyl cyanohydrin with
good yields at room temperature. The LnMOF catalyst has exhib-
ited a similar efficiency for the conversion of aldehydes containing
activating and deactivating groups (Table 3, compounds 4–7). For
compound 4, the yield and reaction time were higher than those
obtained using [Tb(TCA) 4 h and 47% conversion] [31]. Similar
behavior was observed for the conversion of aliphatic aldehydes
the presence of another crystalline phase and a phase transition
collapse when maintained at 120 and 150 C for 1 h (Fig. 2(b)
and (c), respectively). However, the TGA curve does not indicate
the degradation of organic residues at these temperatures. This
phase transition may be attributed to the release of coordinated
water molecules, because the supramolecular structure of the
◦
[
Eu (MELL)(H O) ] is stabilized by hydrogen bonding interactions
2 2 6
among the aqua ligands and the oxygen atoms from neighboring
carboxylate groups. It is important to note that these results are
supported by TGA/DTG. One of our main goals is to tailor the cat-
(Table 3, compounds 12–14). In addition, no polymerization or
decomposition reactions of furfuraldehyde were detected (com-
pound 10). In similar compounds, the yield of ortho-substituted
compounds is lower than the para-substituted compounds. 4-
Hydroxy benzaldehyde is converted to the corresponding product
in just 3 h (compound 7) while 2-hydroxy benzaldehyde is con-
verted to the corresponding product in only 6 h with 83% yield.
We investigated the potential for recycling and reuse of
alytic activity of [Eu (MELL)(H O) ] via surface activation, because
2
2
6
the superficial water removal allows for the interaction between
the aldehydes and the Lewis acids sites [28]. Therefore, the mate-
◦
rial was submitted to milder thermal treatment (100 C for 1 h) to
avoid the structural phase transition while exposing the Lewis acid
sites.
[
Eu (MELL)(H O) ] in the addition reaction of TMSCN to 2-
2 2 6
The catalytic activities were assessed by optimized reactions
between benzaldehyde and TMSCN in toluene (5.0 mL) at room
temperature. The reaction times were monitored by TLC, and the
conversions of benzaldehyde to O-TMS-phenylcyanohydrin-2 were
determined by gas chromatography (GC). Table 1 shows the exper-
imental parameters, such as catalyst masses, reaction time and
substrate conversions (%), for the catalytic assays.
furfuraldehyde. The catalyst was used without pretreatment
(
[
only filtration was performed), and we found that the activated
Eu (MELL)(H O) ] could be recycled and reused at least five con-
2
2
6
secutive times without loss of activity, reaction yields or product
purity. 98%, 89%, 88%, 86% and 85% of the O-trimethylsilyl cyanohy-
drin was isolated after the first, second, third, fourth and fifth cycles,
respectively.
As observed in Table 1, the reaction without the catalyst pro-
ceeded for a longer time period (10 h) and yielded only 8% of the
product. However, the reactions performed in the presence of the
MOF materials exhibited rapid conversion (3 h) accompanied by
good product yields. Based on the same catalyst mass and reaction
time, the thermally activated [Eu (MELL)(H O) ] exhibited supe-
Table 3
Addition of TMSCN to several aldehydes catalyzed by activated (1).
Compound
R
Time (h)
Substrate
conversion (%)#
2
2
6
rior catalytic activity compared to [Eu (MELL)(H O) ] (72 and 44%
3
4
5
6
7
8
9
2-Naphthyl
4-NO2-C6H4
4-Br-C6H4
5
3
3
6
3
6
3
1
3
3
3
3
83
93
92
75
95
83
62
100
85
65
99
69
2
2
6
of substrate conversion, respectively). The effect of the amount
of catalyst was investigated, and the results demonstrate that an
increase in the mass of the catalyst results in an increase in the
reaction yields. To investigate the effects of different solvents, sub-
stituent groups and steric hindrances of several aldehydes, we have
chosen to use 10.00 mg of catalyst. In order to investigate the role
of different solvents in the reaction, we have applied on the addi-
tion of TMSCN to benzaldehyde different solvents and the results
are summarized in Table 2.
4-CH3-C6H4
4-OH-C6H4
2-OH-C H
6
4
2-Pyridyl
2-Furfuryl
5-NO2-2-furfuryl
Penthyl
Ethyl
10
11
12
13
14
Piperonyl
It is important to note that the catalyzed reactions performed
in polar aprotic solvents exhibit high O-TMS-phenylcyanohydrin
#
Conditions: Aldehyde: TMSCN (1:2), 10 mg of activated (1) in acetonitrile at
room temperature. The conversions of aldehydes to OTMS-cyanohydrins were
determined by GC analysis relative to dodecane as an internal standard.
(
2, R = H) yields in less than 180 min of those realized in toluene.

P.K. Batista et al. / Journal of Molecular Catalysis A: Chemical 379 (2013) 68–71
71
4
. Conclusion
The LnMOF, [Eu (MELL)(H O) ], was produced via microwave-
[6] (a) J. Lee, O.K. Farha, J. Roberts, K.A. Scheidt, S.T. Nguyen, J.T. Hupp, Chem. Soc.
Rev. 38 (5) (2009) 1450–1459;
(
b) L.Q. Ma, C. Abney, W.B. Lin, Chem. Soc. Rev. 38 (5) (2009) 1248–1256;
2
2
6
(c) K. Ohara, M. Kawano, Y. Inokuma, M. Fujita, J. Am. Chem. Soc. 132 (1) (2009)
30–31.
assisted hydrothermal synthesis, and its performance as
heterogeneous catalyst for the cyanosilylation of aldehydes has
been demonstrated. The efficacy of the catalyst increased due to
surface defects induced by simple thermal treatment (100 C for
1
activity compared to the as-prepared material for the addition
reactions of TMSN to benzaldehyde (72 and 44% of substrate con-
version). [Eu (MELL)(H O) ] was tested for the addition of TMSCN
to various aldehydes and found to exhibit relatively high catalytic
activity independent of the nature of the substituent (alkyl, aryl,
activating or deactivating) or structural isomerism The catalyst
was recycled several times without loss of activity, reaction yields
or product purity. The reported methodology provides the first
example of the application of [Eu (MELL)(H O) ] as a Lewis acid
a
[
7] P. Horcajada, T. Chalati, C. Serre, B. Gillet, C. Sebrie, T. Baati, J.F. Eubank, D.
Heurtaux, P. Clayette, C. Kreuz, J.S. Chang, Y.K. Hwang, V. Marsaud, P.N. Bories,
L. Cynober, S. Gil, G. Ferey, P. Couvreur, R. Gref, Nat. Mater. 9 (2) (2010)
172–178.
◦
h). This thermally treated catalyst has shown superior catalytic
[8] S. Bordiga, C. Lamberti, G. Ricchiardi, L. Regli, F. Bonino, A. Damin, K.P. Lillerud,
M. Bjorgen, A. Zecchina, Chem. Commun. (20) (2004) 2300–2301.
[
9] Y. Liu, W. Xuan, Y. Cui, Adv. Mater. 22 (37) (2010) 4112–4135.
[10] R.J. Kuppler, D.J. Timmons, Q.-R. Fang, J.-R. Li, T.A. Makal, M.D. Young, D. Yuan, D.
Zhao, W. Zhuang, H.-C. Zhou, Coord. Chem. Rev. 253 (23–24) (2009) 3042–3066.
2
2
6
[
[
[
11] (a) B. Kesanli, W. Lin, Coord. Chem. Rev. 246 (1–2) (2003) 305–326;
b) S. Qiu, G. Zhu, Coord. Chem. Rev. 253 (23–24) (2009) 2891–2911.
(
12] H.C. Aspinall, J.F. Bickley, N. Greeves, R.V. Kelly, P.M. Smith, Organometallics 24
(14) (2005) 3458–3467.
13] (a) S. Kobayashi, M. Sugiura, H. Kitagawa, W.W.L. Lam, Chem. Rev. 102 (6) (2002)
2227–2302;
(
b) C.-J. Li, L. Chen, Chem. Soc. Rev. 35 (1) (2006) 68–82.
[14] K. Deleersnyder, H. Mehdi, I.T. Horváth, K. Binnemans, T.N. Parac-Vogt, Tetra-
hedron 63 (37) (2007) 9063–9070.
15] (a) W.M. Faustino, O.L. Malta, E.E.S. Teotonio, H.F. Brito, A.M. Simas, G.F. de Sá,
J. Phys. Chem. A 110 (7) (2006) 2510–2516;
2
2
6
heterogeneous catalyst for the cyanosilylation of carbonyl com-
pounds.
[
(
b) J.A. Vale, W.M. Faustino, P.H. Menezes, G.F. de Sa, J. Braz. Chem. Soc. 17 (5)
Acknowledgments
(2006) 829–831;
(
(
c) J.A. Vale, W.M. Faustino, P.H. Menezes, G.F. de Sa, Chem. Commun. (31)
2006) 3340–3342.
The authors gratefully acknowledge CNPq and CAPES for their
financial support and LNLS (proposal D10A-XRD2—10164) for pro-
viding the facilities.
[
16] J.C. Tarr, J.S. Johnson, Org. Lett. 11 (17) (2009) 3870–3873.
[17] J. Inanaga, H. Furuno, T. Hayano, Chem. Rev. 102 (6) (2002) 2211–2225.
18] (a) D.T. Mowry, Chem. Rev. 42 (1948) 189;
b) M. North, Introduction of the Cyanide group by Addition to C O, in: S.-I.
[
(
Murahashi (Ed.), Science of Synthesis Volume 19, Compounds with Four and
Three Carbon-Heteroatom Bonds, Georg Thieme Verlag, Stuttgart, 2004, pp.
References
235–284.
[
1] (a) J.R. Long, O.M. Yaghi, Chem. Soc. Rev. 38 (5) (2009) 1213–1214;
b) O.M. Yaghi, M. O‘Keeffe, N.W. Ockwig, H.K. Chae, M. Eddaoudi, J. Kim, Nature
23 (6941) (2003) 705–714;
c) J.L.C. Rowsell, O.M. Yaghi, Microporous Mesoporous Mater. 73 (1–2) (2004)
–14.
2] (a) A. Corma, H. Garcia, F.X. Llabres, Chem. Rev. (2010);
b) S. Opelt, S. Türk, E. Dietzsch, A. Henschel, S. Kaskel, E. Klemm, Catal. Com-
[19] (a) D.H. Ryu, E.J. Corey, J. Am. Chem. Soc. 126 (26) (2004) 8106–8107;
(b) H. Yang, L. Zhang, P. Wang, Q. Yang, C. Li, Green Chem. 11 (2) (2009).
[20] (a) M. North, D.L. Usanov, C. Young, Chem. Rev. 108 (2008) 5146;
(b) N.H. Khan, R.I. Kureshy, S.H.R. Abdi, et al., Coord. Chem. Rev. 252 (2007) 593.
[21] T. Ladrak, S. Smulders, O. Roubeau, S.J. Teat, P. Gamez, J. Reedijk, Eur. J. Inorg.
Chem. (24) (2010) 3804–3812.
[22] H.C. Aspinal, Chem. Rev. 102 (2002) 1807, and references cited therein.
[23] (a) M.O. Rodrigues, F.A. Paz, R.O. Freire, G.F. de Sa, A. Galembeck, M.C. Mon-
tenegro, A.N. Araujo, S. Alves, J. Phys. Chem. B 113 (36) (2009) 12181–12188;
(b) S.C. Xiang, Z.J. Zhang, C.G. Zhao, K.L. Hong, X.B. Zhao, D.R. Ding, M.H. Xie,
C.D. Wu, M.C. Das, R. Gill, K.M. Thomas, B.L. Chen, Nat. Commun. (2011) 2;
(c) Y. Takashima, V.M. Martinez, S. Furukawa, M. Kondo, S. Shimomura, H.
Uehara, M. Nakahama, K. Sugimoto, S. Kitagawa, Nat. Commun. (2011) 2.
[24] H.M. Rietveld, J. Appl. Crystallogr. 2 (1969) 65–71.
(
4
(
3
[
[
(
mun. 9 (6) (2008) 1286–1290.
3] (a) M.D. Allendorf, C.A. Bauer, R.K. Bhakta, R.J.T. Houk, Chem. Soc. Rev. 38 (5)
(
2009) 1330–1352;
(
b) J. Rocha, F.A.A. Paz, F.N. Shi, R.A.S. Ferreira, T. Trindade, L.D. Carlos, Eur. J.
Inorg. Chem. (33) (2009) 4931–4945;
c) M.-S. Wang, S.-P. Guo, Y. Li, L.-Z. Cai, J.-P. Zou, G. Xu, W.-W. Zhou, F.-K. Zheng,
G.-C. Guo, J. Am. Chem. Soc. 131 (38) (2009) 13572–13573;
d) M.O. Rodrigues, N.B. da Costa, C.A. de Simone, A.A.S. Araujo, A.M. Brito-Silva,
F.A.A. Paz, M.E. de Mesquita, S.A. Junior, R.O. Freire, J. Phys. Chem. B 112 (14)
2008) 4204–4212.
4] (a) S. Achmann, G. Hagen, J. Kita, I.M. Malkowsky, C. Kiener, R. Moos, Sensors 9
(
(
[25] (a) Larson, A.C., Von Dreele, R.B. General Structure Analysis System (GSAS); Los
Alamos national Laboratory: Los Alamos, 9/26/2004, 2004; p. 224;
(b) B.H. Toby, J. Appl. Crystallogr. 34 (2001) 210–213.
(
[
[
[26] M. Jarvinen, J. Appl. Crystallogr. 26 (4) (1993) 525–531.
(
3) (2009) 1574–1589;
[27] R.A. Young, P. Desai, In Crystallite Size and Microstrain Indicators in Rietveld
refinement, Archiwun Nauki o Materialach 1989 (1989) 71–90.
[28] K. Schlichte, T. Kratzke, S. Kaskel, Microporous Mesoporous Mater. 73 (1–2)
(2004) 81–88.
[29] M. Gustafsson, A. Bartoszewicz, B. Martín-Matute, J. Sun, J. Grins, T. Zhao, Z. Li,
G. Zhu, X. Zou, Chem. Mater. 22 (2010) 3316.
(
b) V. Harbuzaru Bogdan, A. Corma, F. Rey, L. Jordá Jose, D. Ananias, Carlos, D.
Luis, J. Rocha, Angew. Chem. Int. Ed. 48 (35) (2009) 6476–6479;
c) Z. Xie, L. Ma, K.E. deKrafft, A. Jin, W. Lin, J. Am. Chem. Soc. 132 (3) (2009)
22–923.
5] (a) A. Demessence, A. Mesbah, M. Francois, G. Rogez, P. Rabu, Eur. J. Inorg. Chem.
(
9
(
(
25) (2009) 3713–3720;
b) Y.-J. Zhang, T. Liu, S. Kanegawa, O. Sato, J. Am. Chem. Soc. 132 (3) (2009)
[30] S.A. Sapchenko, D.G. Samsonenko, V.P. Fedin, I. Boldog, K.V. Domasevich, Russ.
J. Coordination Chem. 37 (2) (2011) 100–106.
9
12–913.
[31] P. Wu, J. Wang, Y. Li, C. He, Z. Xie, C. Duan, Adv. Funct. Mater. 21 (2011) 2788.