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Co (II) Complexes with Schiff Base Ligands: Synthesis and EXAFS Study
This content has been downloaded from IOPscience. Please scroll down to see the full text. 2016 J. Phys.: Conf. Ser. 755 012031 (http://iopscience.iop.org/1742-6596/755/1/012031) View the table of contents for this issue, or go to the journal homepage for more
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International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012031 doi:10.1088/1742-6596/755/1/012031
Co (II) Complexes with Schiff Base Ligands: Synthesis and EXAFS Study Ashutosh Mishra1, Amantulla Mansuri1, Samrath Ninama2, Apurva Trivedi3, Sushma Patidar1, Mahesh Jamod1, Ruchita Awate1 1
School of Physics, Devi Ahilya University, Khandwa Road Campus, Indore-452001, India Kasturbagram Rural Institute, Kasturbagram Indore-452001, India 3 SICA College Indore-452003, India
2
Email :
[email protected],
[email protected] Abstract.Thesynthesis of transition metal Schiff base complexes of Co(II) are prepared by chemical root method. Obtained by the condensation of O-phenylenediamine, salicylaldehyde and isatin / 2-hydroxy- 1 Naphthaldehyde is presented. The complexes were characterized by Co- K- edge EXAFS measurements using the dispersive beam line at 2.5GeV energy of Indus2 synchrotron radiation source RRCAT Indore. The recorded EXAFS data were analyzed using the computer software Athena for determine the nearest neighboring distances (bond lengths) of these complexes with conventional methods and were compared with Fourier transform (FT) analysis.
1. Introduction: Schiffbase have been playing an important part in the development of Co-ordination chemistry. Schiff base metal complexes have been studied extensively because of their attractive chemical and physical properties and their wide range of application in numerous scientific areas. They play in important role in both synthetic and structural research, because of their preparative accessibility and structural diversity. Schiff base of o-phenylediamine and its complexes have a variety of application including biological, clinical and analytical [1-2]. The nature of a complex sample is best revealed by the application of several different experimentaltechniques, with each individual measurement providing both unique and complementaryinformation.EXAFS have been used extensively in the investigation of local atomic structures such asthe number and type of neighbouring atoms, inter-atomic distances and disorder. Since the applicationof EXAFS does not require the materials to have long-range order. It is well suited for determining thelocal structures of both non-crystalline materials. The well-markedEXAFS feature on the high energyside of the K-absorption edge up to several hundred eV has been observed in the cobalt complexes.From the knowledge of EXAFS, we have calculated the bond length for the following cobalt complexeswith the help of Levy’s, LSS, Lytle and Fourier transform methods. 2. Experimental Technique: 2.1. Preparation of Schiff bas L1/L2: A solution of o-phenylenediamine (0.005 mol) in alcohol was added to a mixture of isatin/ 2-hydroxy 1naphthaldehyde (0.005mol) and salicylaldehyde(0.005mol) in 20 ml alcohol. The mixture was refluxed for about 30 minutes. The mixture was cooled in ice.The resulting precipitate was then filtered, washed with ethanol and dried. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1
International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012031 doi:10.1088/1742-6596/755/1/012031
2.1. Preparation of complex: To anethanolic solution of the Schiff base Ligand L1/L2 an ethanolic solution of the metal (cobalt chloride) was added in molar ratio (1:1).The mixture was refluxed for about 30 minutes.The mixture was cooled in ice.The resulting precipitate was then filtered, washed with ethanol and dried. EXAFS Analysis The X-ray absorption spectra have been recorded using synchrotron radiation.The X- ray spectroscopy setup is available at Raja Ramanna Centre for Advanced Technology (RRCAT) and is called beam line .This beam line BL-8 has been recently commissioned at the 2.5 GeV Indus-2 synchrotron radiation sources. 3. Result and discussion: EXAFS Bond determination using Different methods (i) Levy’s method In Levy’s method, the bond lengths are given by R1 = [151/ΔE]1/2 Å,Where, ΔE is the difference in eV of the energies of the EXAFS maximum B and minimumand R1is the radius of the first coordination sphere [1]. (ii) Lytle’s method The energy values (E) of the EXAFS maxima, according to Lytle for p symmetry, i.e., Q = 2.04, 6.0,12.0, and 20.0. To evaluate the radius Rsof equivalent polyhedron through the relation [2]Rs= [37.60 / M]1/2. (iii) Lytle, Sayers and Stern’s (LSS) method In the LSS method for determination of the nearest neighbour distances, gives the value of 2(R1 - α1) / π where R1 is the bond length [3-4]. (iv) Fouriertransforms method Bond length has also been determined by the Fourier transformation method for the cobalt complexesstudied however, determined only the phase uncorrected bond lengths by this method. No attempt hasbeen made to employ the fitting procedures by which phase corrected bond length can be determined,because the required crystallographic data is not available for any of the complexes studied. The bond lengths are calculated using Levy’s, LSS and Lytle methods. The values of bond length R is tabulated in table 1. The bond lengths obtained in Co(II) Complexes by LSS, Levy’s, and Lytle method with F.T. methodare comparable each other. 4. Conclusion As pointed out above, the LSS method, Levy’s, Lytle and the Fourier transformation method give the value of bond length R, are comparable to each other. This distance is called the phase uncorrected bond length. It can be seen from table.1 that the phase uncorrected bond lengths obtained from these two methods agree with each other within the limits experimental error. Table 1: Average values of the bond length in (Å) for the Co (II) Complexes. Complexes Co foil Co1 Co2
RLSS 1.45 1.38 1.39
RLevy 1.55 1.48 1.44
RLytle 1.35 1.37 1.32
2
RF.T. 1.38 1.37 1.35
International Conference on Recent Trends in Physics 2016 (ICRTP2016) IOP Publishing Journal of Physics: Conference Series 755 (2016) 012031 doi:10.1088/1742-6596/755/1/012031 0.6
Co2
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Figure 1 Energy spectra of Co foil, Co complex1 and Co complex2. 0.3
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Figure 3 bond length by Fourier Transformation magnitude of Co foil, Co complex1 and Co complex2. Acknowledgments The author is thankful to Dr.Pratibha Sharma School of Chemical Science DAVV Indore for sample preparation andDr. S N Jha RRCAT Indore India for providing EXAFS facility of synchrotron Radiation Source. References [1] kumar B, Rai B K and Ambastha N 2011 J Chem. 27 1173 [2] [3] [4] [4] [5]
Raman N, Pitchaikani Raja Y and Kulandaisamy A 2001 ProcIndAcad Sci. 113 183 Levy R M 1965 J. Chem. Phys. 43 1846 Lytle F W, Sayers D E and Stern E A 1975 Phys. Rev. B 11 4825 Lee J D 1991 Concise of Inorganic Chemistry 4th ed. (Chapman & Hall, London) Sandler S R and Karo W 1971 Organic Functionally Group Preparations II, (New York: Academic press).
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