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material (1 g) being treated with a mixture of ethanol (100 mL) and
conc. HCl (1 mL, 38 % in weight) at 80 °C for 6 h. The resulting
product was filtered, washed with ethanol and dried.
Keywords: Silicotungstic acid · Mesoporous materials ·
Zirconia · Polyoxometallates · Electrostatic interactions ·
Supported catalysts
Synthesis of Silicotungstic Acid Supported on Amine-Function-
alized Mesoporous Zirconia (SW-AZrO2): Silicotungstic acid
(H4[SiW12O40], 0.3 g) was added to AZrO2 (1 g) dispersed in water
(20 mL), and the mixture was stirred at 60 °C for 24 h. The obtained
precipitate was filtered off, washed with excess water to remove
unreacted silicotungstic acid and dried under vacuum for 6 h. The
synthesis of the catalyst is shown in Scheme 1. Tetrakis(tetrabutyl-
ammonium) silicotungstate was prepared by the same procedure
with tetrabutylammonium bromide instead of 1-butyl-3-methyl-
imidazolium bromide.[14]
[1] I. V. Kozhevnikov, Chem. Rev. 1998, 98, 1–390. The entire issue is devoted
to polyoxometallates.
[2] T. Okuhara, N. Mizuno, M. Misono, Adv. Catal. 1996, 41, 113–252.
[3] C. L. Hill, C. Chrisina, M. Prosser-McCartha, Coord. Chem. Rev. 1995, 143,
407–455.
[4] N. Mizuno, K. Yamaguchi, K. Kamata, Coord. Chem. Rev. 2005, 249, 1944–
1956.
[5] G. Yihang, H. Changwen, J. Mol. Catal. A 2007, 262, 136–148.
[6] F. Saeid, B. Zaynab, M. Mansoureh, Acta Chim. Solv. 2006, 53, 72–76.
[7] Y. Hongxun, L. Tianfu, C. Minna, L. Hongfang, G. Shuiying, C. Rong, Chem.
Commun. 2010, 46, 2429–2431.
[8] K. Jun, N. Yoshinao, U. Sayaka, Y. Kazuya, M. Noritaka, Chem. Eur. J. 2006,
12, 4176–4184.
[9] Y. Kazuya, Y. Chie, U. Sayaka, M. Noritaka, J. Am. Chem. Soc. 2005, 127,
530–531.
[10] L. Xianjun, L. Zhen, X. Chungu, Synth. Commun. 2008, 38, 1610–1616.
[11] Y. Shi Xian, F. Wei Jun, J. Mol. Catal. A 2008, 280, 142–147.
[12] M. D. Tzirakis, I. N. Lykakis, M. Orfanopoulos, Chem. Soc. Rev. 2009, 38,
2609–2621.
[13] B. Ankur, F. Lefebvre, S. B. Halligudi, J. Catal. 2007, 247, 166–175.
[14] a) T. Rajkumar, G. Ranga Rao, Mater. Chem. Phys. 2008, 112, 853–857; b)
R. Thouvenot, M. Fournier, R. Franck, C. Rocchiccioli-Deltcheff, Inorg.
Chem. 1984, 23, 598–605.
Catalytic Procedure for Esterification of Maleic Acid with Butan-
1-ol: Esterification of maleic acid with butan-1-ol was carried out
in a two-necked round-bottomed flask at 95 °C for 5 h. Maleic acid
(0.861 mmol) was added to a stirred dispersion of catalyst (125 mg)
in butan-1-ol (2 mL). Small aliquots of sample were withdrawn peri-
odically (1, 3 and 5 h) and monitored for the progress of the reac-
tion by gas chromatography (Shimadzu 2014) with use of a capillary
column (Rtx-5, 30 m × 0.32 mm ID × 1 μm) and FID detector. Nitro-
gen was used as the carrier gas at a flow rate of 37.1 mL min–1 and
a column flow of 1.1 mL min–1. The products were confirmed by
GC–MS (Perkin–Elmer). A Clarus 680 chromatograph with capillary
column (Elite-5MS, 30 m × 0.25 mm ID × 250 μm df) was connected
to a Clarus 600 (EI) mass spectrometer. The maleic acid conversion
and product selectivity was calculated by use of the equation given
below.
[15] T. Rajkumar, G. Ranga Rao, Mater. Lett. 2008, 62, 4134–4136.
[16] L. Baoshan, M. Wei, L. Jianjun, Z. Shengli, L. Xianfen, J. Colloid Interface
Sci. 2011, 362, 42–49.
Initial mol-% – Final mol-%
Conversion (mol-%) =
× 100
Initial mol-%
[17] M. Biju Devassy, S. B. Halligudi, J. Catal. 2005, 236, 313–323.
[18] B. Siddhartha Kumar, D. Dipak Kumar, Appl. Clay Sci. 2011, 53, 347–352.
[19] J. H. Sepúlveda, J. C. Yori, C. R. Vera, Appl. Catal. A 2005, 288, 18–24.
[20] a) F. Bentaleb, O. Makrygenni, D. Brouri, C. Coelho Diogo, A. Mehdi, A.
Proust, F. Launay, R. Villanneau, Inorg. Chem. 2015, 54, 7607–7616; b) L.
Xiujuan, Y. Chun, PhysChemChemPhys 2011, 13, 7892–7902.
[21] a) T. Aliakbar, A. Mansour, N. Ali, K. Maryam, M. A. Mostafa, J. Colloid
Interface Sci. 2006, 303, 32–38; b) I. Kei, I. Toru, K. Yuichi, O. Toshio, Y.
Shoji, Angew. Chem. Int. Ed. 2007, 46, 7625–7628; Angew. Chem. 2007,
119, 7769.
Selectivity in favour of dibutyl maleate (%) =
GC peak area of dibutyl maleate
× 100
Sum of GC peak area of monobutyl and dibutyl maleate
Supporting Information (see footnote on the first page of this
article): Wide-scan XPS of SW-AZrO2, C 1s narrow scan of SW-AZrO2,
UV/Vis diffuse reflectance spectra of AZrO2 and SW-AZrO2, mass
spectrum of monobutyl maleate, mass spectrum of dibutyl
maleate.
[22] F. Hoffmann, M. Cornelis, J. Morell, M. Fröba, Angew. Chem. Int. Ed. 2006,
45, 3216–3251; Angew. Chem. 2006, 118, 3290.
[23] R. Gopalan, C. H. Chang, Y. S. Lin, J. Mater. Sci. 1995, 30, 3075–3081.
[24] M. Yuichi, K. Shin-ichi, K. Katsuya, J. Asian Cer. Soc. 2014, 2, 11–19.
[25] S. Euaggelia, N. L. Ioannis, S. A. Gerasimos, RSC Adv. 2014, 4, 8402–8409.
[26] G. S. Armatas, G. Bilis, M. Louloudi, J. Mater. Chem. 2011, 21, 2997–3005.
[27] K. M. Parida, M. Sujata, J. Mol. Catal. A 2007, 275, 77–83.
[28] S. Zhou, G. Garnweitner, M. Niederberger, M. Antonietti, Langmuir 2007,
23, 9178–9187.
[29] S. Scholz, S. Kaskel, J. Colloid Interface Sci. 2008, 323, 84–91.
[30] A. Tarafdar, P. Pramanik, Microporous Mesoporous Mater. 2006, 91, 221–
224.
[31] K. Luo, S. Zhou, L. Wu, G. Gu, Langmuir 2008, 24, 11497–11505.
[32] K. M. Parida, S. Mallick, P. C. Sahoo, S. K. Rana, Appl. Catal. A 2010, 381,
226–232.
[33] M. Sujata, R. Surjyakanta, K. Parida, Dalton Trans. 2011, 40, 9169–9175.
[34] A. Zaidi, J. L. Gainer, G. Carta, Biotechnol. Bioeng. 1995, 48, 601–605.
[35] M. Bhagiyalakshmi, K. Shanmugapriya, M. Palanichamy, A. Banumathi, V.
Murugesan, Appl. Catal. A 2004, 267, 77–86.
[36] B. Makowka, H. Block, Bayer Aktiengesellschaft, US Patent 4827022,
1989.
[37] M. Bhagiyalakshmi, S. Vishnu Priya, J. Herbert Mabel, M. Palanichamy, V.
Murugesan, Catal. Commun. 2008, 9, 2007–2012.
[38] K. T. Venkateswara Rao, P. S. Sai Prasad, N. Lingaiah, Green Chem. 2012,
14, 1507–1514.
[39] F. J. Berry, G. R. Derrick, J. F. Marco, M. Mortimer, Mater. Chem. Phys. 2009,
114, 1000–1003.
Acknowledgments
We would like to thank the following organizations for lab
space, supplies and equipment. The authors thank the Depart-
ment of Science and Technology (DST), New Delhi (grant num-
ber SR/S3/CE/23/2008), the Department of Chemical Engineer-
ing IIT-Madras, the Directorate of Extramural Research & Intel-
lectual Property Rights, Defence Research and Development Or-
ganization (ER&IPR, DRDO) (grant number ERIP/ER/0800344/M/
01/1098), and the Council of Industrial and Scientific Research
(CSIR), New Delhi (grant number 01 (2226)/08/EMR-II) for finan-
cial support. B. S. Abdur Rahman University is duly acknowl-
edged for characterization of samples (FTIR and GC). The Amrita
Centre for Nanosciences and Molecular Medicine, Kochi, is
gratefully acknowledged for XPS analysis. The authors are grate-
ful to the PSG Institute of Advanced Studies, Coimbatore, for
TEM characterization and thank Startech Labs PVT Ltd., Hydera-
bad, for offering ICP-OES support.
Eur. J. Inorg. Chem. 2016, 1697–1705
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