IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Formation of Binuclear Metal Complexes with Multidentate Schiff-base Oxime Ligand: Synthesis and Spectral Investigation I. O. Issa, M. J. Al-Jeboori* and J. S. Al-Dulaimi Department of Chemistry, College of Education, Ibn AL-Haitham, University of Baghdad Received in : 27 August 2008 Accepted in : 12 November 2008 Abstract The new polydentate Schiff-base oxime (1E,1`E)-2hydroxy-3-((E)-(2-((E)-2- hydrxy3-((E)-(hydroxyimino)methyl)-5-methylbenzyldeneamino)ethy limino)methyl)-5- methylbenzaldehyde oxime H4L and its binuclear metal complexes with Mn(II), Fe(II), Co(II) and Cu(II) are reported. The reaction of 2,6 diformyl–4–methyl phenol with hydroxyl amine hydrochloride in mole ratios of 1:1 gave the precursor (E)-2-hydroxy-3- ((hydroxyimino)methyl)-5-methylbenzaldehyde. Condensation reaction of precursor with ethy lenediamine in mole ratios of 2:1 gave the new N4O2 Schiff-base oxime ligand H4L. Upon complex formation, the ligand behaves as a tribasic hexadantate species. The mode of bonding and overall geometry of the complexes were determined through physico-chemical and spectroscopic methods. These studies revealed tetrahedral geometries for Mn(II), Fe(II), Co(II) complexes and square planar geometry about Cu(II) complex of general formulae [M 2(HL)](Cl)(H2O). M olecular structure of the for Mn(II), Fe(II), Co(II) complexes has been optimised by CS Chem 3D Ultra Molecular Modeling and Analysis Program and supported four coordinate geometry . Keywords: Schiff-base ligand; (1E,1`E)-2hydroxy-3-((E)-(2-((E)-2-hydrxy3-((E) (hydroxyimino)methyl)-5-methylbenzyldeneamino)ethy limino)methyl)-5-methylbenzaldeh- yde oxime; Binuclear complexes; Structural study. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Introduction The development of Schiff-base species based on transition metal compounds and polydentate ligands has been the subject of extensive research due to their potential applications in materials science [1, 2] and environmental chemistry and medicine. Schiff- base compounds p lay a vital role in coordination chemistry, due to their ability to react with a range of metal ions forming stable complexes which have applications in different fields. One interesting application in the field of coordination chemistry has been to investigate the use of Schiff-base ligands to develop phenoxo-bridged binuclear complexes with homometallic and/or heterometallic centres. This includes design molecules containing paramagnetic metal centres are able to self-assemble through metal-ligand interactions rendering supramolecular assemblies with interesting structural and magnetic properties. [3- 7]. Schiff-base metal complexes also have applications in biomedical [8, 9], biomimetic and catalytic systems [10, 11]. Oxime chemistry is one vital research field for inorganic and bioinorganic chemist. The role of oximes and their metal complexes, in particular cobalt- oximes, in the biological systems make them one interested branch in the coordination and organometallic chemistry. Significant publications dealt with the development of coordination chemistry are related to the preparation and charachterisation of oximes and their metal complexes. These include the investigation of new synthetic methods and coordination modes of oxime species upon complexation [12]. It is well known that oxime and oximato species can bind a metal in different coordination modes. Gupta et al. [13] reported a simple and general route to the synthesis of organo-cobaloximes with mixed dioxime ligands of the general formula, [RCo(L)(dpgH)py] (where: L= dmgH and ChgH; R= Me–Decane: DmgH= dimethyl glyoxime; ChgH= 1,2–cyclohexanedioneglyoxime). The mode of bonding was investigated through physico-chemical and spectroscopic methods. X–ray crystal structures confirmed the preparation of six-coordinate cobal-oxime complexes. It is well documented that oxime compounds and their complexes with transition metals have many applications in medicine, biology, industry, and catalysis [14]. Recently, we reported the formation of polymeric chain assemblies of some phenoxo-bridged binuclear transition metal ions with the mutidentate Schiff-base (E)-6,6`-((1E,1`E)-(ethane-1,2-diylbis(azan-1-yl- 1-ylidene))bis(methan-1-yl-ylidene))bis(4-methyl-2-((E)(pyridine-2-ylmethylimino)methyl) phenol). The ligand has been specifically designed in which the involvement of the pyridyl moieties played effective role in ensuring the formation of ladder-type structures [15]. As part of our continuing efforts to explore the use of multidentate Schiff-base ligands for the synthesis of new complexes, we describe here the synthesis and spectral investigation of some phenoxo-bridged binuclear transition metal ions with the new multidentate oxime- Schiff-base IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 ligad namely (1E,1`E)-2hydroxy-3-((E)-(2-((E)-2-hydrxy3-((E)-(hydroxyimino)methyl)-5- methylbenzyldeneamino)ethy limino)methyl)-5- methylbenzaldehyde oxime H4L. Experimental Materials and methods All reagents were obtained commercially (Aldrich) and used without further purification. Solvents used in the synthesis were distilled from appropriate drying agent immediately prior to use. 2,6-Diformyl-4-methyl-phenol was prepared by a method published in [16]. Physical measurements Elemental analyses (C, H and N) were carried out on a Heraeus instrument (Vario EL). IR spectra were recorded as KBr or CsI discs using a Shimadzu 8300 FTIR spectrophotometer from 4000-250 cm -1. Melting points were obtained on a Buchi SMP-20 capillary melting point apparatus and are uncorrected. Electronic spectra were measured from 200-900 for 10-3 M solutions in DMF at 25C using a Shimadzu 160 spectrophotometer. Mass spectra obtained by positive Electron Impact (EI) recorded on a VG autospec micromass spectrometer. Metals were determined using a Shimadzu (A.A) 680 G atomic absorption spectrophotometer. Conductivity measurements were made with DMF solutions using a Jenway 4071 digital conductivity meter and room temperature magnetic moments were measured with a magnetic susceptibility balance (Jonson M attey Catalytic System Division). Synthesis Preparation of the precursor (E)-2-hydroxy-3-((hydroxyimino)methyl)-5- methylbenzaldehyde To a mixture of 2,6–diformyl–4–methyl phenol (5.0 g, 30.0 mmol) dissolved in ethanol (5 mL) was added a mixture of hydroxylamine hydrochloride (2.12 g, 30.0 mmol) in H2O (15mL). The mixture was stirred, and then cooled to (–5C). An aqueous solution of sodium hydroxide (20 %) was added slowly, and the temperature was kept below (0 C) with vigorous stirring for 2 h. The mixture was diluted with water (50 mL), and unreacted materials were removed by filtration. Glacial acetic acid was added to the filtrate to adjust it to a neutral pH. The solid was collected by filtration, washed with benzene and air dried, to give (3.25 g, 60%) of the title compound, m.p. = 142C. IR data (cm -1 ): 3238 ν(O– H)oxime, 3310 ν(O–H)phenol, 1637 ν(C=O), 1604 ν(C=N), 1265 ν(C–O), 1060 ν(N–O). IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Preparation of the Schiff-base H4L A solution of ethylenediamine (0.5g, 8.0 mmol) in methanol (10 mL) was added slowly to a mixture of the precursor (3.0 g, 16 mmol) dissolved in methanol (20 mL). The reaction mixture was allowed to reflux for 2 h, and then stirred at room temperature for a further 1 h. A light brown solid was collected by filtration, recrystallised from a mixture of hot methanol/ H2O (1:1) and dried under vacuum to give the ligand as a light–brown solid. Yield (3.75 g, 59%), m.p = 165C. IR data (cm-1): 3310 ν(O–H)phenolic; 3238 ν(O–H)oxime; 1629, 1637 ν(C=N)imine; 1575, 1565 ν(C=N)oxime; 1373 ν(Phenoxide); 1039, 1020 ν(N-O); 1373 ν(phenoxide) and 2374 ν(H–O … H). The positive EI mass spectrum of H4L showed the following fragments; 338 (5 %) [M–(CH=N–OH)] + , 231 (3 %) [M–(CH=N–OH–C6H2–Me– OH)]+, 214 (64 %) [M–{CH=N–OH–C6H2–Me–(OH)2}]+, 186 (12 %) [M–{CH=N–OH– C6H2–Me–(OH)2–N=CH}]+, 132 (3 %) [M–{CH=N–OH–C6H2–Me–(OH)2–N–CH–(CH2)2– N=CH}]+, 89 (5 %) [M–{CH=N–OH–C6H2–Me–(OH)2–N=CH–(CH2)2–N=CH–CH=N– OH}]+. General synthesis of the complexes A solution of the Schiff-base (1 mmol) and potassium hydroxide (2.1 mmol) in methanol (25 mL) was stirred for 15 min. A methanolic solution (15 mL) of the metal chloride salt (2 mmol) was then added dropwise. The resulting mixture was refluxed under N2 for 2 h, resulting in the formation of a solid mass which was washed several times with methanol (10 mL), and then ether (15 mL). Elemental analysis data, colours and yields for the complexes are given in (Table 1). Molecular modelling 3D molecular modelling of the proposed structure of the complexes was performed using CS Chem 3D Ultra Molecular Modelling and Analysis Program [17]. It is an interactive graphics program that allows rapid structure building, geometry optimization with minimum energy and molecular display. It is well known program and has the ability to handle transition metal complexes [18]. The correct stereochemistry was assured through the manipulation and modification of the molecular coordinates to obtain reasonable low energy molecular geometries. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Results and Discussion The precursor (E)-2-hydroxy-3-((hydroxyimino)methyl)-5-methylbenzaldehyde (Scheme 1 A) was obtained by condensation reaction using one equivalents of 2,6-diformyl- 4-methyl-phenol and one equivalent of hydroxyl amine hydrochloride. The IR spectrum of the precursor showed characteristic bands due to the ν(O-H) oxime and ν(O-H) phenol, ν(C=O), ν(C=N), ν(N-O), and ν(C=C) functional groups. The reaction of (E)-2-hydroxy-3- ((hydroxyimino)methyl)-5-methylbenzaldehyde with ethylenediamine in mole ratios of 2:1, respectively afforded the new Schiff-base oxime (1E,1`E)-2hydroxy-3-((E)-(2-((E)-2- hydrxy3-((E)-(hydroxyimino)methyl)-5-methylbenzy-ldeneamino)ethy limino)methyl)-5- methylbenzaldehyde oxime H4L in moderate yield (Scheme 1B). Scheme 1: Chemical structures of precursor and Schiff-base oxime ligand The Schiff-base oxime was characterised by elemental analysis (Table 1), IR (Table 2), UV–Vis (Table 3) spectroscopy and mass spectrometry. The IR spectrum of the free Schiff- base shows characteristic bands at 1629; 1576; 1039, 1020 and 3238 cm -1 due to the ν(C=N) imine, ν(C=N) oxime, ν(N-O) and ν(O-H) of the oxime functional groups, respectively. The spectrum showed also abroad band at 3310 cm –1 assigned to the ν(O–H) stretching of the phenol group. The weak bands appeared around 2374 and 1762 cm–1 are due to the ν(H– OH) stretching and (H–O…H) bending indicating the presence of the hydrogen bonding in the molecule. The UV-Vis spectrum of H4L IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 exhibits an intense absorption peak at 285 nm, assigned to    * . The peak at 350 nm assigned to n → π* transition. The mass spectrum does no show the parent ion fragment (M). This may be due to the harsh condition (EI technique) used to obtain the spectrum. The mass spectrum was consistent with the proposed structural formula. Figure 1 shows the EI spectrum of the ligand, while the fragmentation pattern of the ligand displayed in scheme 2. Scheme 2: Mass fragmentation pattern of the Schiff base oxime ligand The bridged phenoxy binuclear complexes of the ligand with MnII, FeII, CoII and CuII were synthesised by heating 1 mmole of the ligand with 2 mmole of the metal chloride in methanol using potassium hydroxide as a base. The use of a base in these reactions was found to be essential since otherwise only an intractable mixture was recovered. However, in methanolic potassium hydroxide, deprotonation of the ligand occurs facilitating the formation of the complexes [M II 2(HL)](Cl).H2O (M = Mn(II), Fe(II), Co(II) and Cu(II)) (Scheme 3). The complexes are air-stable solids, soluble in DM F but not in other common organic solvents. The coordination geometries of the complexes were deduced from their spectra. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 The analytical data (Table 1) agree well with the suggested formulae. Conductivity measurements of Mn(II), Fe(II), Co(II), Cu(II), Cd(II) and Hg(II) complexes lie in the 54.6- 77.9 cm 2Ω-1mol-1 range, indicating their 1:1 electrolytic behavior (Table 1) [19]. Scheme 3: Proposed structures of binuclear Schiff-base oxime ligand The important infrared bands for the complexes together with their assignments are listed in Table 2. The IR spectra of the complexes exhibited H2L bands with the appropriate shifts due to complex formation (Table 2). The absence of a peak around 3310 cm -1 in all the complexes indicate the absence of phenolic ν(OH) due to deprotonation followed by complexation [20]. The ν(C=N)imine and ν(C=N)oxime stretching bands at 1637 and 1575 cm-1, respectively in the free Schiff-base is shifted to lower frequency and observed around 1610- 1629 cm-1 and 1496-1560 for the complexes. The bands are assigned to a ν(C=N) stretch of reduced bond order. This can be attributed to delocalisation of metal electron density (t2g) to the π-system of the ligand [21, 22], indicating coordination of nitrogen of the C=N moieties to the metal atoms [23]. Further, bands in the region of 1527–1558 cm -1 in all the complexes suggest phenoxide bridging with the metal atoms [15, 24]. The strong ν(N–O) stretching bands at 1039 and 1020 cm –1 in the free ligand are shifted to higher frequencies and appeared at 1085-1184 and 1033-1160 cm–1 for the complexes. The increase in the N–O bond order can be attributed to the distribution of the -electron of the oxime moiety upon complex formation IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 [25]. It seems that the two N–O bands are non–equivalent. These results are in accord with those reported by Al–Jeboori et al. [26]. At lower frequency the complexes exhibited bands around 410–450 and 536–581 cm -1 which could be assigned to ν(M–N) and ν(M–O) vibration modes, respectively [15, 21]. Due to the larger dipole moment change for M–O compared to M–N, the ν(M–O) usually appears at higher frequency than the ν(M–N) band [27]. Additional bands at 2516–2560 and 1650–1750) cm–1 were assigned to ν(H–O…H) and (H– O … H), respectively. The broad band observed around 34800-3527 cm -1 assigned to (H2O) lattice molecule [28]. The electronic spectra and magnetic moment data of the dimeric complexes are summarised in (Table 3). The electronic spectra of the complexes Mn(II), Fe(II), Co(II) and Cu(II) exhibit a high intensity peak around 299-355 nm related to the intra- ligand field transition. The electronic spectrum of the Mn(II) complex showed additional peaks at 315 and 396 nm assigned to the charge transfer (CT) and d–d transitions, respectively in a distorted tetrahedral geometry [29, 30]. The observed magnetic moment of this complex is typical for a terahedral structure. The electronic spectrum of the Fe(II) complex is consistent with tetrahedral assignment [29, 31]. The magnetic moment of this complex is typical for tetrahedral structure. The spectrum of the Co(II) complex exhibited two bands characteristic of tetrahedral Co(II) complexes [29-32]. The magnetic moment was consistent with the tetrahedral environment around Co(II). The magnetic moment value (Table 3) observed for the Cu(II) complex agrees well with the proposed square planar geometry . The electronic spectrum of the Cu(II) complex shows a broad band which can be attributed to 2B1g → 2B2g transition, corresponding to square planar geometry [29, 33]. The magnetic moment values for the binuclear complexes at RT are lower than the predicted values. This may arise from metal–metal interactions through the phenolic oxygen atoms and/or extensive electron delocalisation, which may be related to the formation of dimeric structures [34, 35]. Dmolecular modelling and analysis of bonding modes Molecular mechanics attempts to reproduce molecular geometries, energies and other features by adjusting bond length, bond angles and torsion angles to equilibrium values that are dependent on the hybridization of an atom and its bonding scheme. In order to obtain estimates of structural details of these complexes and in view the four-coordination of all the complexes, we have optimized the molecular structure of [Co II 2(HL)](Cl)(H2O) as a representative compound (Figure 2). The details of bond lengths and bond angles per the 3D molecular structure are given in Tables 4. Energy minimization was repeated several times to find the global minimum [36]. The energy minimization value for tetrahedral and without restricting the structure for the Co-complex is almost same i.e, 560.8472 Kcal /mol. The molecular modelling for the modulated Co(II)-complex (figure 2 and Table 4) shows the bond IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 lengths bond angles around copper atom which indicate the distorted tetrahedral geometry around Co(II) ion [37], and thus the proposed structure of the Co(II)-complex as well as of the others, are acceptable. Conclusion In this paper, we have explored the synthesis and coordination chemistry of some binuclear complexes derived from the multidentate Schiff-base oxime ligand H4L. The ligand behaves as a tribasic octadentate species upon complexation with the involvement of the nitrogen atoms of the oxime groups in coordination for all complexes. The low magnetic moment values of these complexes are in accord with the formation of phenoxy-bridged binuclear metal complexes. References 1. Lehn, J.M . (1995) Supramolecular chemistry concepts and perspectives, 1st edn. Wiley- VCH, Weinheim 2. Belghoul, B.; Welterlich, W.; Maier, A.; Toutianoush, A.; Rabindranath, A.R.and Tieke, B. (2007) Langmuir, 23 :5062. 3. Tripuramullu, B. K.; Kishore, R. and Das, S. K. (2010) Polyhedron 29: 2985-2990. 4. Shuvaev, K. V.; Dawe, L. N. and Thompson, L.K., (2010) Eur. J. Inorg. Chem., 4583- 4586. 5. Shiu, K. B.; Liu, S. A.and Lee, G. H. (2010) Inorg. Chem. 49: 9902-9908. 6. Yesiel, O. Z.; Erer, H., Kastas, G., Kani, I., Polyhedron, 29: (2010) 2600-2608. 7. Habib, H.A.; Gil-Hernandez, B.; Abu-Shandi, K.; Sanchiz, J.and Janiak, C., Polyhedron, (2010) 29: 2537-2545. 8. Al-Jeboori, M.J. and Al-Shihri, A. S., (2000) J Saudi Chem Soc., 5:341. 9. Al-Jeboori, M.J. and Kashta, A.A. (2004) Mu’Tahlil-Buhuth Wadirasat, 19: 89. 10.Costamagna, J., Ferraudi, G., Matsuhiro, B., Vallette, M.C., Canales, J., Villagra’n, M., Vargas, J., Aguirre, M.J., Coord. Chem. Rev., 196 (2000) 125. 11. Coughlin, P.K., Lippard, S.J., J. Am. Chem. Soc., 106(1984) 2328. 12. Pombeiro, A.J.L., and Kukushkin, V.Y., Coordination Chemistry, 1 (2004) 631–637. 13. Gupta, B.D., Singh, V., Yamuna, R., Barclay, T., and Cordes, W., Organometallics, 22 (2003) 2670–2678. 14. Bowman, K., Gaughan, A.P., and Dori, Z., J. Am Chem. Soc., 94 (1972) 727. 15. Al-Jeboori, M.J., Hasan, H.A., Al-Sa’idy, W.A. J, Transition Met. Chem., 34 (2009) 593–598. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 16. Verani, C.N., Rentschler, L., Thomas, W., Bill, E., and Chaudhuri, P., J. Chem. Soc. Dalton Trans., (2000) 251. 17. CS Chem 3D Ultra Molecular Modeling and Analysis, Cambridge, www. cambridgesoft.com. 18. Maurya, R.C., Rajput, S., Journal of Molecular Structure, 794 (2006) 24.34. 19. Geary W.J., Coord. Chem. Rev., 7(1971) 81. 20. Saravanakumar, D., Sengottuvelan, N., Priyadarshni, G., Kandaswamy, M., Okawa, H., Polyhedron, 23 (2004) 665. 21. Al-Jeboori, M.J., Al-Dujaili, A.H. and Al-Janabi, A.E., Transition Met. Chem., 34 (2009) 109. 22. Livingston, S.E., Mayfield, J.H., Moorse, D.S., Aust. J. Chem., 28(1975) 2531. 23. El-Sonbati, A.Z., El-bindary A.A., Al-Sarawy, A.A., Spectrochim Acta Part A, 58 (2002) 2771. 24. Sreedaran, S., Bharathi, KS., Rahiman, A.K.,, Rajesh, K., Nirmala, G., Jagadish, L., Kaviyarasan, V., Narayanan, V., Polyhedron, 27 (2008) 1867. 25. Hadzi, D., J. Chem. Soc., 15 (2004) 2725. 26. Al-Jeboori, M. J., Abdul Rahman, A. S. A., and Atia, S., Ibn AL–Haitham J. for Pure & Appl. Sci., vol. 18, No. 2 (2005) 51–67. 27. Nakamoto, K., and Ohkaku, N., Inorg. Chem., 10 (1971) 798. 28. Nakomoto, K., Infrared Spectra of Inorganic and Coordination Compounds, (1996) 4 th ed., J. Wiely and Sons, New York. 29. Lever, A.B.P., (1984) Inorganic Electronic Spectroscopy, 2nd edn., Elsevier publishing, New York. 30. Figgis, B.N., (1967) Introduction to Ligand Fields, Interscience Publishers, John Wiley and Sons, New York, p.285. 31. Nasman, O.S.M., (2008) Phosphorus, Sulfur, and Silicon, 183 : 1541–1551. 32. Aly, M.M.; Baghlaf, A.O.; Ganji, N.S. (1985)Polyhedron, 4 : 1301. 33. Yousif, E., Farina, Y., Kasar, K., Graisa, A., and Ayid, K., American Journal of Applied Sciences, 6 (4) (2009) 582-585 34. Okawa, H.; Tadokora, M.; Aratake, T.Y.; Ohba M.; Shindom, K.; Mitsumi, M.; Koikawa, M.; Tomono, M.and Fenton, D.E. (1993) J. Chem. Soc. Dalton Trans., 253. 35. Jin, Y.;Yoon, I.; Seo, J.; Lee, J-E., Moon, S-T., Kim, J., Han, S.W., Park, K-M ., Lindoy, L.F., and Lee, S.S., (2005) Dalton Trans., 788. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 36. Mishra, A P.; Mishra, R.K. and Shrivastava, S.P. (2009) Journal of the Serbian Chemical Society, 74: 523.535. 37. Børsting, P. and Steel, P.J. Eur. (2004) J. Inorg. Chem., 376-380. Table(1): Colours, yields, elemental analyses, and molar conductance values. Compound Colour Yield (%) m.p ºC Found (Calcd.) (%) M(cm2Ω-1mol-1) M C H N Cl H4L Light brown 59 165 - 62.9 6.3 14.2 - - (62.8) (5.6) (14.6) [MnII 2(HL)](Cl)(H2O) Brown 70 190 19.4 45.7 3.9 9.9 6.8 54.6 (19.7) (45.3) (4.2) (10.1) (6.4) [Fe II 2(HL)](Cl)(H2O) Dark red 65 210 19.5 45.5 3.8 9.9 6.1 77.9 (20.0) (45.2) (4.2) (10.0) (6.4) [CoII 2(HL)](Cl)(H2O) Blue 68 180 21.2 45.1 4.2 9.6 6.6 70.8 (20.9) (44.7) (4.1) (9.9) (6.3) [CuII 2(HL)](Cl)(H2O) Green 66 215 22.3 43.7 3.7 10.1 5.8 69.7 (22.1) (44.0) (4.0) (9.8) (6.2) Table (2): IR frequencies (cm –1) of the compounds. Compound ν(C=N)iminic ν(C=N)oxime ν(Phenoxide) ν(N-O) ν(H–O…H) ν(M-O) ν(M- N) H4L 1637, 1929 1575, 1565 1373 1039, 1020 2374 - - [MnII 2(HL)](Cl).H2O 1620 1560 1538 1085, 1033 2518 536 450 [Fe II 2(HL)](Cl).H2O 1618 1550 1545 1087, 1047 2516 541 410 [Co2(HL)](Cl).H2O 1610 1504 1527 1114, 1083 2518 584 425 [Cu2(L)(H2O)2]Cl2 1629 1569 1558 1184, 1160 2560 585 435 IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Table(3): Magnetic moment and u.v-vis spectral data in DMF solutions. Compound eff (BM) Band position Extinction coefficient Assignments (per atom) ( nm) max(dm 3 mol -1 cm -1 ) H4L 285 930   * 350 420 n  * [Co II 2(HL)](Cl).H2O 3.88 299 1600 Ligand field 607 185 4T1g (F) → 4T1g (P) 678 281 4T1g (F) → 4A2g (F) [MnII 2(HL)](Cl).H2O 4.9 297 780 Ligand field 366 1100 CT 414 101 6A1g 4T1g [Fe II 2(HL)](Cl).H2O 5.2 355 644 Ligand field 375 388 CT 418 200 5E2 (D)  5T2 (D) [Cu II 2(HL)](Cl).H2O 1.46 299 1500 Ligand fied 383 478 CT 650 250 2B1g → 2A1g ___________________________________________________________________________ Table(4): Proposed bond lengths and bond angles of [Co2(HL)](Cl)(H2O). Type of bond Bond lengths(Å) Type of bond Bond angles() Co1–N1 1.844 N1–Co1–N2 81.0196 Co1–N2 1.849 N4–Co2–N3 79.7111 Co2–N3 1.855 O2–Co1–O1 58.6714 Co2–N4 1.857 O1–Co2–O2 58.5915 Co1–O1 1.872 N1–Co–O1 83.7982 Co1–O2 1.877 N1–Co1–O2 128.0165 Co2–O1 1.860 N2–Co1–O1 112.1927 Co2–O2 1.893 N2–Co1–O2 81.8360 N3–O3 1.381 N3–Co2–O2 110.1736 N4–O4 1.333 N4–Co2–O2 79.6107 C=N1 1.872 N4–Co2–O1 128.2319 H2C=N1 1.510 N3–Co2–O1 87.0565 H2C=N2 1.502 Co1–O2–Co2 98.8544 C=N3 1.274 Co1–O1–Co2 100.2434 C=N4 1.278 C–O1 1.547 C–O2 1.529 O–H 0.894 O…H 1.199 (Å) = Angstrom () = Degree IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (2) 2011 Fig.(1): (EI) mass spectrum of the Schiff-base oxime ligand Fig.(2): 3D molecular modelling of complex [Co II 2(HL)] + 2011) 2( 24المجلد مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة یة متعددة السن میز تكوین معقدات ثنائیة النواة للیكاند قواعد شف اوك دراسات تشخیصیةمع تحضیر : الدلیميشهاب الجبوري، جاسم عیسى عمران عیسى ، محمد جابر جامعة بغداد،كلیة التربیة ابن الهیثم ،قسم الكیمیاء 2008آب 27: استلم البحث في 2008تشرین الثاني 12:قبل البحث في الخالصــة متعددة السناوكزیمیة تضمن البحث تحضیر لیكاند قاعدة شف ـائي [ ــــ ــــ ــــي -2(ثنـــ ــــ ــــ ــــیم -3-هایدروكسـ ــــ ــــ ـــل أوكسـ ــــ ــــ ــــد -5-فورمایــ ــــ ــــ ــــل بینزیالدأمایـ ــــ ــــ ـــروجین -)میث ــــ ــــ ــــاث -نتــ ــــ ــــ ) H4L(ینیلـ الكوبلت(ومعقداتها ثنائیة النواة مع )II( ، المنغنیز )II( ، الحدید )II( ، النحـاس )II( –diformyl 2,6تـم تحضـیرالیكاند بمفاعلـة) . 4–methyl phenol مع hydroxyl amine hydrochloride .1:1وبالنسبة المولیة 2-hydroxy-3-((hydroxyimino)methyl)-5-methylbenzaldehyde-(E)لیعطي المشتق ـة (H4Lلیعطـي الیكانـد االوكسـیمي نــوع 2:1فـي الخطـوة االخیـرة تــم مفاعلـة المشـتق مـع االثلــین داي امـین وبالنسـبة المولیـ N4O2(عنـد تكـوین المعقــد یكـون الیكانــد ثالثـي القاعدیــة سداسـي المـنح)ـا طبیعـة التأصــر ).الســن واشـكال المعقــدات تـم تعینهـ ــــة ــــالطرق الطیفیةوالفیزیاویـ ــــدات .بـ ــاعي الســـــطوح لمعقـ ــق الربـــ ــات التناســـ ــت هـــــذه الدراســـ ـــــت(اعطـــ ـــز)II(الكوبل ، )II(، المنغنیـــ :وشكل المربع المستوي حول ایون النحاس وبالصیغة العامة التالیة))II(الحدید [M 2(HL)](Cl)(H2O). CS Chem 3D ستخدام برنامج تم توضیح الشكل الجزیئي للمعقدات با .والذي اوضح التناسق الرباعي للمعقدات تحضیر مع دراسات تشخیصیة قواعد شف ،لیكاند،اوكزیم ،معقدات ثنائیة النواة:الكلمات المفتاحیة