Sonochemical synthesis of a new nano-plate lead(II) coordination polymer constructed of maleic acid
Graphical abstract
A new nano-sized lead(II) coordination polymer of maleic acid (H2Mal), [Pb(μ7-Mal)]n (1), has been synthesized by sonochemical method and characterized by scanning electron microscopy, X-ray powder diffraction, elemental analyses and IR spectroscopy. The compound 1 was structurally characterized by single-crystal X-ray diffraction. Thermal stability of nano and bulk samples of compound 1 were studied and compared with each other.
Introduction
Within the field of coordination polymers, efforts to use metal ions and organic spacers simultaneously have recently been developed [1], [2], [3], [4], [5], [6], [7], [8]. During the past decades, a number of these compounds, with interesting polymeric motifs, have been successfully designed and synthesized. Some of them exhibit encouraging potential for application in catalysis, nonlinear optics, gas separation, magnetic properties, and molecular recognition [5]. Lead(II)–carboxylate systems containing mono-, di-, and polycarboxylate [9], [10], [11], [12] have been studied extensively in the construction of metal–organic networks. In contrast to inorganic nanomaterials, specific syntheses of nano-structured coordination polymers seems to be surprisingly sparse, and to date most investigations on coordination polymers have been carried out only in the solid state and studies of their properties were limited to investigations at the macroscopic scale. The potential use of coordination polymers as materials for nanotechnological applications would seem to be very extensive as nanometer-scaled materials often exhibit the new interesting size-dependent physical and chemical properties that can not be observed in their bulk analogous.
Although considerable effort has been dedicated to the controlled synthesis of nanoscale particles of metals, oxides, sulfides, and ceramic materials, little attention was focused to date on nanoparticles of supramolecular compounds such as coordination polymers [13]. Several different synthetic approaches have been offered for the preparation of coordination polymers. Some of them are (1) slow diffusion of the reactants into a polymeric matrix, (2) diffusion from the gas phase, (3) evaporation of the solvent at ambient or reduced temperatures, (4) precipitation or recrystallisation from a mixture of solvents, (5) temperature controlled cooling and (6) hydrothermal synthesis. In this paper we describe a simple synthetic sonochemical preparation of nano-structures of a new coordination polymer, [Pb(μ7-Mal)]n (1), {(H2Mal = maleic acid}, and on their conversion into nano-structured lead(II) oxide by calcination at moderately elevated temperature. Sonochemistry is the research area in which molecules undergo a chemical reaction due to the application of powerful ultrasound radiation (20 kHz–10 MHz) [14]. Ultrasound induces chemical changes due to cavitation phenomena involving the formation, growth, and instantaneously implosive collapse of bubbles in a liquid, which can generate local hot spots having a temperature of roughly 5000 °C, pressures of about 500 atm, and a lifetime of a few microseconds [15]. These extreme conditions can drive chemical reactions which have been developed to fabricate a variety of nano compounds [14]. In recent years many kinds of nanomaterials have been prepared by this method [15], [16], [17], [18], [19], [20], [21], [22], [23], [24], [25].
Section snippets
Experimental
All reagents and solvents for the synthesis and analysis were commercially available and were used as received. A multiwave ultrasonic generator (Sonicator_3000; Misonix, Inc., Farmingdale, NY, USA) was used. IR spectra were recorded using Perkin–Elmer 597 and Nicolet 510P spectrophotometers. Microanalyses were carried out using a Heraeus CHN-O-Rapid analyzer. Melting points were measured on an Electrothermal 9100 apparatus and are uncorrected. The thermal behavior was measured with a PL-STA
Results and discussion
The reaction between maleic acid (H2Mal) and lead(II) nitrate using two different routes provided crystalline materials of the general formula [Pb(μ7-Mal)]n (1). Scheme 1 gives an overview of the methods used for the synthesis of [Pb(μ7-Mal)]n (1) using the two different routes.
The elemental analysis and IR spectra of the nano-plates and of the single crystalline material are indistinguishable. The relatively weak IR absorption bands around 2965 cm−1 are due to the C–H modes involving the
Conclusion
A new Pb(II) coordination polymer, {[Pb(μ7-Mal)]n (1), H2Mal = maleic acid} has been synthesized using a thermal gradient approach and by sonochemical irradiation. Compound 1 was structurally characterized by single-crystal X-ray diffraction. The crystal structure of compound 1 consists of a two-dimensional polymer and shows the coordination number in the Pb(II) ions is seven. Reduction of the particle size of the coordination polymers of 1 to a few dozen nanometers results in lower thermal
Acknowledgements
This work was supported by the Payame Noor and Tarbiat Modares Universities.
References (29)
- et al.
Coord. Chem. Rev.
(2009) - et al.
J. Mol. Struct.
(2009) - et al.
Ultrason. Sonochem.
(2010) Coord. Chem. Rev.
(1986)J. Magn. Chem. Mater
(1994)- et al.
Electrochim. Acta
(2001) - et al.
J. Catal.
(2001) - et al.
Ultrason. Sonochem.
(2010) - et al.
Ultrason. Sonochem.
(2009) - et al.
Ultrason. Sonochem.
(2010)
Chem. Eng. J.
Ultrason. Sonochem.
Ultrason. Sonochem.
Chem. Rev.
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