Journal of Nanoparticles

Journal of Nanoparticles / 2013 / Article
Special Issue

Nano/Microstructured Materials: Rapid, Low-Cost, and Eco-Friendly Synthesis Methods

View this Special Issue

Research Article | Open Access

Volume 2013 |Article ID 546194 |

Jalal Albadi, Abdolhossein Razeghi, Hossein Abbaszadeh, Azam Mansournezhad, "CuO- Nanocomposite: An Efficient Recyclable Catalyst for the Synthesis of Aryl-14H-dibenzo[a-j]xanthenes", Journal of Nanoparticles, vol. 2013, Article ID 546194, 5 pages, 2013.

CuO- Nanocomposite: An Efficient Recyclable Catalyst for the Synthesis of Aryl-14H-dibenzo[a-j]xanthenes

Academic Editor: Hamed Bahmanpour
Received07 Jan 2013
Revised16 Feb 2013
Accepted20 Feb 2013
Published25 Mar 2013


CuO-CeO2 nanocomposite is reported as a highly efficient recyclable catalyst that is applied for the synthesis of Aryl-14H-dibenzo[a-j]xanthenes under solvent-free conditions. The catalyst was synthesized by coprecipitation method and characterized by X-ray powder diffraction (XRD), BET specific surface area, field emission scanning electron microscopy (FESEM), and energy dispersive spectroscopy (EDS) analysis. The copper nanoparticles are dispersed as fine and amorphous phases on the surface of ceria and made nanoclusters with average size of about 33 nm. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any losing of its efficiency. This procedure provides several advantages such as simple workup, mild reaction conditions, short reaction times, and high yields of the products.

1. Introduction

In recent years, nanocatalysis has emerged as a sustainable and competitive alternative to conventional catalyst since the nanoparticles possess a high-surface-to-volume ratio, which enhances their activity and selectivity, while, at the same time, maintaining the intrinsic features of a heterogeneous catalyst [1]. In particular, nanocrystalline oxides have proved to be useful to chemists in the laboratory and industry due to the good activation of adsorbed compounds and reaction rate enhancement, selectivity, easier workup and recyclability of the supports, and the eco-friendly green reaction conditions [26]. Also, the practical applications of nanocomposite metal oxides as the catalysts in organic synthesis have been increased due to their high catalytic activity because of the high surface area [7, 8]. The recyclability of the catalyst is the added advantage in the case of these catalysts. The catalytic activity of CuO-CeO2 nanocomposite is well known for the oxidation of CO in H2-rich streams [9]. Xanthene derivatives are important class of compounds that received significant attention from many pharmaceutical and organic chemists because of the broad spectrum of their biological and pharmaceutical properties such as antibacterial [10], anti-inflammatory [11], and antivirial properties [12]. Furthermore, these compounds are used as dyes and fluorescent material for visualization of biomolecules and in laser technologies due to their useful spectroscopic properties [13, 14]. Aryl-14H-dibenzo[a-j]xanthenes are among the most important classes in the family of xanthenes due to their distinctive structures and great potential for the further transformations [15]. Various methods have been reported for the synthesis of Aryl-14H-dibenzo[a-j]xanthenes; among these methods, the one-pot condensation of β-naphthol with aldehydes is the most common procedure. Therefore, various catalysts have been developed for the improvement of this reaction [1625]. In the continuation of our research program to develop the efficient, and green catalysts in organic synthesis [2629], herein, we wish to report a green, efficient and recyclable catalyst for the synthesis of Aryl-14H-dibenzo[a-j]xanthenes under solvent-free conditions (Scheme 1).


2. Experimental

All products were identified by the comparison of their spectral and physical data with authentic samples. Chemicals (2-naphthol, aromatic aldehydes, cerium, and copper nitrates) were purchased from Merck Chemical company in Germany. Yields refer to isolated pure products.

2.1. Catalyst Preparation

CuO-CeO2 nanocomposite was prepared by coprecipitation method using aqueous solution of cerium and copper nitrates and drop-wise adding KOH as precipitant agent under vigorous mixing, while temperature and pH were fixed at unique values. Then, acquired sample was filtered, washed, and calcined to obtain final catalyst for using atsynthesis of Aryl-14H-dibenzo[a-j]xanthenes.

2.2. General Procedure for Synthesis of Aryl-14H-dibenzo[a-j]xanthenes

A mixture of 2-naphthol (2 mmol), aldehyde (1 mmol), and CuO-CeO2 nanocomposite (0.05 g) was added to a round-bottomed flask. The reaction mixture was placed in an oil bath at 80°C and magnetically stirred for the appropriate times according to Table 1. After completion of the reaction (monitored by TLC), the mixture reaction was cooled to room temperature, next acetone (10 mL) was added, and the mixture stirred for 5 min. Then, the catalyst was recovered by filtration to be reused subsequently. The filtrate was evaporated to dryness, and the solid residue recrystallized from hot ethanol to give pure products in high yields. The experimental procedure with this catalyst is very simple and the catalyst can be removed easily by filtration. The solid products were easily recrystallized from hot ethanol and were obtained in good to high yields during the short reaction times. Very low amount of the catalyst is needed. Moreover, our procedure is environmentally friendly as it does not use any toxic auxiliary or solvent.

EntryAldehydeTime (min)Yield (%)aM. P. (°C)

22-NO2C6H4CHO1291 213–215
52-ClC6H4CHO12 90 213–215

aIsolated yield. bProducts were characterized by the comparison of their spectroscopic data (NMR and IR) and melting points with those reported in the literature [17, 18].
2.3. Catalyst Characterization

The catalyst structure characterization was performed by X-ray powder diffraction (XRD), using a Bruker AXS D8 advanced diffractometer equipment with CuKα radiation (λ = 1.5406 A°). The Debye-Scherrer equation is used to determine average crystallite size of nanoparticles. Field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS) carried out by a Hitachi S4160 instrument to see the morphology, the evaluation of cluster size, and the metal composition of the catalyst. BET specific surface area was estimated from the N2 adsorption/desorption isotherms, measured at 77°K using a Quantachrome CHEMBET-3000 instrument.

3. Results and Discussions

XRD pattern of fresh CuO-CeO2 nanocomposite calcined at 450°C is illustrated (Figure 1). The main reflection placed at 2θ range of 15–80° indicates a cubic fluorite structure with highest intensity at (1, 1, 1) plane that belongs to the XRD standard JCPDS card number of 43-1002. According to the pattern of pure CeO2 (not shown in the figure), only the diffraction peaks of ceria crystallites are detected, and there is no peaks related to copper oxide nanoparticles. It is supposed that fine dispersion and/or amorphous structure of CuO with low content on the surface of ceria clusters is responsible for absence of copper oxide peaks at the XRD pattern [9, 30, 31]. However, there is some difference between values of unit cell parameters for pure CeO2 and CuO-CeO2 due to lattice shrinkage in surface ceria structure. The calculation showed 5.45 and 5.42°A for CeO2 and CuO-CeO2, respectively. The observed shrinkage may be consequence of partial incorporation of CuO into the CeO2 lattice structure that has been reported for coprecipitation synthesis [30, 31]. The calculated average crystal size of the ceria in the catalyst based on dominant peak at 2θ of 28.5° using Debye-Scherrer equation was 7.5 nm. BET specific surface area result was 131 m2/g that confirms estimated value for average nanoparticle size of the catalyst by XRD test.

Figures 2(a) and 2(b) present FESEM micrograph of the catalyst at two different magnifications to study the morphology and the evaluation of nanoclusters size of catalyst. It seems that 7 nm particles calculated based on the BET surface area are agglomerated to approximately 33 nm sized clusters and made bigger nanostructure CuO-CeO2 catalyst.

EDS analysis (Figure 3) showed the presence of 5.8 and 94.2 wt.% for Cu and Ce elements in the catalyst, respectively.

Optimization of the reaction conditions showed that the best results in the presence of 0.05 g of CuO-CeO2 nanostructured catalyst at 80°C were obtained under solvent-free conditions, when the relative ratio of the aldehyde and 2-naphthol was 2 : 1, respectively. Using these optimized conditions, the reaction of various aromatic aldehydes, containing electron-donating and electron-withdrawing groups, was explored (Table 1). Aliphatic aldehydes remain intact under the same reaction conditions. Therefore, the method can be useful for the chemoselective synthesis of Aryl-14H-dibenzo[a-j]xanthenes from aromatic aldehydes in the presence of aliphatic ones.

The activity of the recycle catalyst was also examined under the optimized conditions, and the desired product was obtained in high yields after 1–8 runs (Table 2). To investigate these property for our introduced catalyst, the reaction of benzaldehyde with 2-naphthol was selected as the model (Table 2). After each reaction, we washed and dried the catalyst with acetone and reused for the next run. This process was repeated for 8 runs, and no appreciable yield decrease was observed.


Time (min)1515151818202025
Yield (%)a9393929292908888

aIsolated yield.

4. Conclusions

We have developed a new, efficient, and green procedure for the synthesis of biologically important xanthene derivatives catalyzed by recyclable CuO-CeO2 nanostructured catalyst, under solvent-free conditions. This catalyst can promote the yields and reaction times over 8 runs without noticeable loss in its efficiency. Moreover, high yields of products, short reaction times, ease of workup, and clean operation are the most important advantages of this method which makes the procedure beneficial compared to conventional methods.


The authors are thankful to the Behbahan Khatam Al-Anbia, University of Technology, for the partial support of this work.


  1. D. Astruc, Nanoparticles and Catalysis, Wiley-VCH, Weinheim, Germany, 2008.
  2. H. Sharghi and M. Hosseini, “Solvent-free and one-step Beckmann rearrangement of ketones and aldehydes by zinc oxide,” Synthesis, no. 8, pp. 1057–1059, 2002. View at: Google Scholar
  3. M. H. Sarvari and H. Sharghi, “Reactions on a solid surface. A simple, economical and efficient Friedel-Crafts acylation reaction over zinc oxide (ZnO) as a new catalyst,” Journal of Organic Chemistry, vol. 69, no. 20, pp. 6953–6956, 2004. View at: Publisher Site | Google Scholar
  4. S. F. Yin, B. Q. Xu, S. J. Wang, C. F. Ng, and C. T. Au, “Magnesia-Carbon nanotubes (MgO-CNTs) nanocomposite: novel support of Ru Catalyst for the generation of COx-free Hydrogen from Ammonia,” Catalysis Letters, vol. 96, pp. 113–116, 2004. View at: Google Scholar
  5. M. T. Drexler and M. D. Amiridis, “Kinetic investigation of the heterogeneous synthesis of flavanone over MgO,” Catalysis Letters, vol. 79, no. 1–4, pp. 175–181, 2002. View at: Publisher Site | Google Scholar
  6. R. S. Varma, “Solvent-free organic syntheses: using supported reagents and microwave irradiation,” Green Chemistry, vol. 1, no. 1, pp. 43–55, 1999. View at: Google Scholar
  7. S. Samantaray, D. K. Pradhan, G. Hota, and B. G. Mishra, “Catalytic application of CeO2-CaO nanocomposite oxide synthesized using amorphous citrate process toward the aqueous phase one pot synthesis of 2-amino-2-chromenes,” Chemical Engineering Journal, vol. 193, pp. 1–9, 2012. View at: Google Scholar
  8. S. Li, W. Zhang, M. H. So, C. M. Che, R. Wang, and R. Chen, “One-pot solvothermal synthesis of Pd/Fe3O4 nanocomposite and its magnetically recyclable and efficient catalysis for Suzuki reactions,” Journal of Molecular Catalysis A, vol. 359, pp. 81–87, 2012. View at: Google Scholar
  9. A. Razeghi, A. Khodadadi, H. Ziaei-Azad, and Y. Mortazavi, “Activity enhancement of Cu-doped ceria by reductive regeneration of CuO-CeO2 catalyst for preferential oxidation of CO in H2-rich streams,” Chemical Engineering Journal, vol. 164, no. 1, pp. 214–220, 2010. View at: Publisher Site | Google Scholar
  10. S. Chatterjee, M. Iqbal, J. C. Kauer et al., “Xanthene derived potent nonpeptidic inhibitors of recombinant human calpain I,” Bioorganic and Medicinal Chemistry Letters, vol. 6, no. 13, pp. 1619–1622, 1996. View at: Publisher Site | Google Scholar
  11. J. P. Poupelin, G. Saint Ruf, O. Foussard Blanpin, G. Narcisse, G. Uchida-Ernouf, and R. Lacroix, “Synthesis and antiinflammatory properties of bis (2 hydroxy 1 naphthyl) methane derivatives,” European Journal of Medicinal Chemistry, vol. 13, no. 1, pp. 67–71, 1978. View at: Google Scholar
  12. O. Sirkecioglu, N. Tulinli, and A. Akar, “Synthesis of 14-Aryl-14H-dibenzo[a-j]xanthenes,” Journal of Chemical Research, pp. 502–506, 1995. View at: Google Scholar
  13. R. M. Ion, A. Planner, K. Wiktorowicz, and D. Frackowiak, “The incorporation of various porphyrins into blood cells measured via flow cytometry, absorption and emission spectroscopy,” Acta Biochimica Polonica, vol. 45, no. 3, pp. 833–845, 1998. View at: Google Scholar
  14. R. J. Sarma and J. B. Baruah, “One step synthesis of dibenzoxanthenes,” Dyes and Pigments, vol. 64, no. 1, pp. 91–92, 2005. View at: Publisher Site | Google Scholar
  15. K. Chibale, M. Visser, D. Van Schalkwyk, P. J. Smith, A. Saravanamuthu, and A. H. Fairlamb, “Exploring the potential of xanthene derivatives as trypanothione reductase inhibitors and chloroquine potentiating agents,” Tetrahedron, vol. 59, no. 13, pp. 2289–2296, 2003. View at: Publisher Site | Google Scholar
  16. L. Wu, J. Zhang, L. Fang, C. Yang, and F. Yan, “Silica chloride catalyzed synthesis of 14-aryl-14H-dibenzo[a,i]xanthene-8,13-diones,” Dyes and Pigments, vol. 86, no. 1, pp. 93–96, 2010. View at: Publisher Site | Google Scholar
  17. S. Allameh, A. Davoodnia, and A. Khojastehnezhad, “An efficient and eco-friendly synthesis of 14-Aryl-14H-dibenzo[a-j]xanthenes using H4[SiW12O40] as a heterogeneous and reusable catalyst under solvent-free conditions,” Chinese Chemical Letters, vol. 23, pp. 17–20, 2012. View at: Google Scholar
  18. I. Mohammadpoor-Baltork, M. Moghadam, V. Mirkhani, S. Tangestaninejad, and H. R. Tavakoli, “Highly efficient and green synthesis of 14-aryl(alkyl)-14H-dibenzo[a,j] xanthene and 1,8-dioxooctahydroxanthene derivatives catalyzed by reusable zirconyl triflate [ZrO(OTf)2] under solvent-free conditions,” Chinese Chemical Letters, vol. 22, no. 1, pp. 9–12, 2011. View at: Publisher Site | Google Scholar
  19. A. R. Hajipour, Y. Ghayeb, N. Sheikhan, and A. E. Ruoho, “Brønsted acidic ionic liquid as an efficient and reusable catalyst for synthesis of 14-aryl-or 14-Aryl-14H-dibenzo[a-j]xanthenes under solvent-free conditions,” Synlett, no. 5, pp. 741–744, 2010. View at: Publisher Site | Google Scholar
  20. S. Ko and C. F. Yao, “Heterogeneous catalyst: amberlyst-15 catalyzes the synthesis of 14-substituted-14H-dibenzo[a,j]xanthenes under solvent-free conditions,” Tetrahedron Letters, vol. 47, no. 50, pp. 8827–8829, 2006. View at: Publisher Site | Google Scholar
  21. T. S. Rivera, A. Sosa, G. P. Romanelli, M. N. Blanco, and L. R. Pizzio, “Tungstophosphoric acid/zirconia composites prepared by the sol-gel method: an efficient and recyclable green catalyst for the one-pot synthesis of 14-Aryl-14H-dibenzo[a-j]xanthenes,” Applied Catalysis A, vol. 443, pp. 207–213, 2012. View at: Google Scholar
  22. M. Dabiri, M. Baghbanzadeh, M. Shakouri Nikcheh, and E. Arzroomchilar, “Eco-friendly and efficient one-pot synthesis of alkyl- or Aryl-14H-dibenzo[a-j]xanthenes in water,” Bioorganic and Medicinal Chemistry Letters, vol. 18, no. 1, pp. 436–438, 2008. View at: Publisher Site | Google Scholar
  23. G. B. Dharma Rao, M. P. Kaushik, and A. K. Halve, “An efficient synthesis of naphtha[1, 2-e]oxazinone and 14-substituted-14H-dibenzo [a, j] xanthene derivatives promoted by zinc oxide nanoparticle under thermal and solvent-free conditions,” Tetrahedron Letters, vol. 53, pp. 2741–2744, 2012. View at: Google Scholar
  24. F. Shirini and N. Ghaffari Khaligh, “Succinimide-N-sulfonic acid: an efficient catalyst for the synthesis of xanthene derivatives under solvent-free conditions,” Dyes and Pigments, vol. 95, pp. 789–794, 2012. View at: Google Scholar
  25. R. Kumar, G. C. Nandi, R. K. Verma, and M. S. Singh, “A facile approach for the synthesis of 14-aryl- or alkyl-14H-dibenzo[a,j]xanthenes under solvent-free condition,” Tetrahedron Letters, vol. 51, no. 2, pp. 442–445, 2010. View at: Publisher Site | Google Scholar
  26. J. Albadi, M. Keshavarz, F. Shirini, and M. Vafaie-nezhad, “Copper iodide nanoparticles on poly(4-vinyl pyridine): a new and efficient catalyst for multicomponent click synthesis of 1,4-disubstituted-1,2,3-triazoles in water,” Catalysis Communications, vol. 27, pp. 17–20, 2012. View at: Google Scholar
  27. J. Albadi, N. Iravani, F. Shirini, and F. Dehghan, “A green recyclable poly(4-vinylpyridine)-supported copper iodide nanoparticle catalyst for the chemoselective synthesis of pentaerythritol diacetals from aromatic aldehydes,” Journal of Chemical Research, vol. 36, no. 10, pp. 610–611, 2012. View at: Google Scholar
  28. J. Albadi, N. Iravani, and M. Khoshakhlagh, “A new, green and recyclable poly(4-vinylpyridine)-supported copper iodide nanoparticles catalyst for the synthesis of aryl -14H-dibenzo[a-o]xanthenes,” Iranian Journal of Catalysis, vol. 2, pp. 85–89, 2012. View at: Google Scholar
  29. J. Albadi, M. Keshavarz, M. Abedini, and M. Vafaie-nezhad, “Copper iodide nanoparticles on poly(4-vinyl pyridine) as new and green catalyst for multicomponent click synthesis of 1, 4-disubstituted-1, 2, 3-triazoles in water,” Chinese Chemical Letters, vol. 23, pp. 797–800, 2012. View at: Google Scholar
  30. P. Ratnasamy, D. Srinivas, C. V. V. Satyanarayana et al., “Influence of the support on the preferential oxidation of CO in hydrogen-rich steam reformates over the CuO-CeO2-ZrO2 system,” Journal of Catalysis, vol. 221, pp. 455–465, 2004. View at: Google Scholar
  31. Z. Liu, R. Zhou, and X. Zheng, “Preferential oxidation of CO in excess hydrogen over a nanostructured CuO-CeO2 catalyst with high surface areas,” Catalysis Communications, vol. 9, pp. 2183–2186, 2008. View at: Google Scholar

Copyright © 2013 Jalal Albadi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

More related articles

1637 Views | 1011 Downloads | 11 Citations
 PDF Download Citation Citation
 Download other formatsMore
 Order printed copiesOrder

Related articles

We are committed to sharing findings related to COVID-19 as quickly as possible. We will be providing unlimited waivers of publication charges for accepted research articles as well as case reports and case series related to COVID-19. Review articles are excluded from this waiver policy. Sign up here as a reviewer to help fast-track new submissions.