Ömer üt, Betül Demirezen Kara, Gökhan Apaydn, Erhan Cengiz, Aye Kazanc

1. Kahramanmara Sutcu Imam University, Faculty of Science and Letters, Department of Physics, Kahramanmara, Turkey 2. Karadeniz Technical University, Faculty of Science, Department of Physics, Trabzon, Turkey 3. Alanya Alaaddin Keykubat University, Faculty of Engineering, Engineering Basic Sciences Department, Antalya, Turkey 4. Kahramanmara Sutcu Imam University, Faculty of Science and Letters, Department of Chemistry, 46100 Kahramanmara, Turkey

Abstract In this study, the electronic transition properties and structural analysis of the metal complexes (Ni(Ⅱ), Co(Ⅱ), Cu(Ⅱ) and Mn(Ⅱ)) of three different polymer ligands were performed by using XRF and X-ray diffraction (XRD) techniques, respectively. The structural analysis of the polymers and their complexes were performed by XRD technique and some of the polymers were found to be in the face-centred cubic (fcc) structure. In addition, the values of the present K X-ray intensity ratios are significantly greater than the values reported in literature.

Keywords XRF； XRD； Polymeric azomethine compounds and transition metal complexes

Introduction

1 Experimental

1.1 Preparation of polymeric metal complexes

Polymer1, polymer2 and polymer3 and their Cu(Ⅱ), Co(Ⅱ), Ni(Ⅱ) and Mn(Ⅲ) transition metal complexes were synthesized according to the methods used by Catanescu et al[15](2001) and Jiang et al[16](2006). In addition, these samples were prepared by Kazancand the synthesizing methods of polymers are given in detail in earlier article of Kazancet al[17]and in PhD thesis of Kazanc[18]. In addition, the structure of the polymer ligands and their metal complexes are given in PhD work of Kazanc[18]. Polymer1 was obtained by polymerization of 1,2-phenylenediamine and terephthaldehyde. While obtained orange colour material is soluble in dimethylformamide and in dimethylsulfoxide, they are insoluble in common organic solvents. Polymer2 was obtained by polymerization 1,4-phenylenediamine and okzaldehyde. While the obtained polymer2 is very slightly soluble in hot dimethylformamide, it issoluble in other solvents. Polymer3 was obtained by polymerization of 1,4-fenilendiamin and phthalaldehyde. While obtained polymer3 is soluble in dimethylformamide and dimethylsulfoxide, they are insoluble in other solvents.

1.2 XRF measurement of the polymer and their complex

(1)

where NKα and NKβ are counts observed under the peaks corresponding to Kα and Kβ X-rays, respectively,εKαandεKβare the efficiencies of detector for Kα and Kβ series of X-rays, respectively.Gis the geometry factor andIis the intensity of the source.βKαandβKβare the target self-absorption correction factor for both the incident and emitted radiation. The details of theI0Gεvalues and the self-absorption correction factor are given in our previous reports[7-8, 11].

1.3 XRD measurement of the polymer samples

XRD is an important technique for studying the structural properties of the materials. The Philips X’Pert PRO brand, emitting monochromatic CuKα radiation (λ= 0.154 056 nm), calibrated at 40 kV and 30 mA was used to take XRD measurements of samples. XRD measurements in the whole series of the thin films were done at room temperature, 2θwas between 40° and 100°, in step interval was 0.02°, and waiting time was 0.5 s in each step[7]. The characteristic XRD spectra of polymer ligands and metal complexes were taken. These spectra can be found in previous study of M. Sci thesis of Demirezen[19].The X-ray diffraction crystal structure analysis of the polymer complexes of produced with binding Mn, Co, Ni and Cu were made by XRD technique. The polymer complexes give XRD peaks for which are generally crystallized (except for poly3-Ni (Ⅱ)).

2 Results and Discussion

The measured values of Kβ/Kα X-ray intensity ratios of the polymeric metal complexes are given in Table 1. In addition, XRD measurements were carried out. The resulting peaks till 2θ=20° which are composed of their structure of the polymers. But, the observed peaks after 20° are considered to occur owing to metal ions bound to the polymer. All of the polymeric and transition metal ions conducive to XRD peaks were identified to be in the face-centred cubic structure (fcc). 2θvalues, interplanar distances (d) and hkl planes obtained from XRD diffraction patterns of polymer1, polymer2 and polymer3. In spite of bonding with the same metal ions to three different polymeric structures such as polymer1, polymer2 and polymer3, the obtained XRD peaks were found to be different from each other. The cause of these differences is thought to be due to the different polymeric structures.

Table 1 The values of Kβ/Kα X-ray intensity ratios polymeric azomethine compounds and transition metal complexes

* The other experimental and theoretical values are for pure elements.

As seen from Figure 1, the value of Kβ/Kα X-ray intensity ratios of Poly3-Ni(Ⅱ) complex structure are bigger than that of Poly1-Ni(Ⅱ) complex structure.

Fig.1ThecomparisonofKβ/KαX-rayintensitymeasuredinPoly3-Ni(Ⅱ)andPoly1-Ni(Ⅱ)complexesandthereportedexperimentalandtheoreticalvaluesintheliterature

As shown in Figure 2, the value of Kβ/Kα X-ray intensity ratio of Poly2-Cu(Ⅱ) complex structure was detected to be smaller than that of Poly1-Cu(Ⅱ)complex structure.

Fig.2ThecomparisonofKβ/KαX-rayintensitymeasuredinPoly2-Cu(Ⅱ)andPoly1-Cu(Ⅱ)complexesandthereportedexperimentalandtheoreticalvaluesintheliterature

In addition, as seen from Figure 3, the value of Kβ/Kα X-ray intensity ratios of Poly2-Mn(Ⅲ) complex structure was found to be bigger than that of Poly3-Mn(Ⅲ) complex structure.

Fig.3ThecomparisonofKβ/KαX-rayintensitymeasuredinPoly3-Mn(Ⅲ)andPoly2-Mn(Ⅱ)complexesandthereportedexperimentalandtheoreticalvaluesintheliterature

Fig.4ThecomparisonofKβ/KαX-rayintensitymeasuredinPoly2-Co(Ⅱ)andPoly3-Co(Ⅱ)complexesandthereportedexperimentalandtheoreticalvaluesintheliterature

Finally, as seen from Figure 4, while the value of Kβ/Kα X-ray intensity ratios of poly2-Co(Ⅱ) complex structure are smaller than that of Poly1-Co(Ⅱ), the value of Kβ/Kα X-ray intensity ratios of poly1-Co(Ⅱ) complex structure was detected having smaller than that of Poly3-Co(Ⅱ) complex structure.

The measured Kβ/Kα X-ray intensity ratios are also different because Kβ/Kα X-ray intensity ratios measured elements are connected to the polymer having different structure. The reason for this may be increase or decrease the particularly Kβ X-rays transitions probabilities by change of factors such as the number of ligands, bond length and structure, coordination number in complex structure together with variation of the complex structure of the polymer. This change is affected most Kβ X-rays because Kβ X-rays generally consist of transitions from the outer shells to the inner shells. This variation has a special name that called chemical effects. In other words, the reason for these changes can also be chemical effects on Kβ/Kα X-ray intensity ratios. If an element attend to the chemical compounds, it may be displayed the differences in wavelength, intensity and shape of the line of the emitted X-rays by elements. While these differences increase the emission probability of Kβ X-rays, the emission probability of Kα X-rays may decrease. However, contrary to this event can be also measured. The chemical effects on Kβ/Kα X-ray intensity ratios basically may be connected to the change in the binding energy of the electrons that Auger event may cause. However, 3d elements are more sensitive to the chemical structure because of partially filled valence orbitals and unpaireddelectrons. They have the multi-valency feature to be the outer electron shells of these elements too close together. The average bond length of a molecule varies according to valency. The change of the bond length will be effective in the shape of the molecular orbitals and in the bonding energies of molecular orbital electrons. This change in the binding energy will also be changed emission probability of Auger electrons and X-ray. The uncertainty in experimental measurements is estimated to be about 6% or less.