IBN AL- HAITHAM J. FOR PURE & APPL. S CI. 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 Departme nt of Chemistry, College of Education, I bn AL-Haitham, Unive rsity of Baghdad Received in : 27 August 2008 Accepte d in : 12 November 2008 Abstract The new p olydentate Schiff-base oxime (1E,1`E)-2hy droxy -3-((E)-(2-((E)-2- hy drxy 3-((E)-(hydroxy imino)methy l)-5-methy lbenzy ldeneamino)ethy limino)methy l)-5- methy lbenzaldehyde oxime H4L and its binuclear metal comp lexes with M n(II), Fe(II), Co(II) and Cu(II) are reported. The reaction of 2,6 diformy l–4–methy l p henol with hy droxy l amine hy drochloride in mole ratios of 1:1 gave the p recursor (E)-2-hydroxy -3- ((hy droxy imino)methy l)-5-methy lbenzaldehyde. Condensation reaction of p recursor with ethy lenediamine in mole ratios of 2:1 gave the new N4O2 Schiff-base oxime ligand H4L. Up on comp lex formation, the ligand behaves as a tribasic hexadantate sp ecies. The mode of bonding and overall geometry of the comp lexes were determined through p hy sico-chemical and sp ectroscop ic methods. These studies revealed tetrahedral geometries for M n(II), Fe(II), Co(II) comp lexes and square p lanar geometry about Cu(II) comp lex of general formulae [M 2(HL)](Cl)(H2O). M olecular structure of the for M n(II), Fe(II), Co(II) comp lexes has been op timised by CS Chem 3D Ultra M olecular M odeling and Analysis Program and sup p orted four coordinate geometry . Keywords: Schiff-base ligand; (1E,1`E)-2hydroxy -3-((E)-(2-((E)-2-hy drxy 3-((E) (hy droxy imino)methy l)-5-methy lbenzyldeneamino) ethy limino)methy l)-5-methy lbenzaldeh- y de oxime; Binuclear comp lexes; Structural study . IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 Introduction The development of Schiff-base sp ecies based on transition metal comp ounds and p oly dentate ligands has been the subj ect of extensive research du e to their p otential applications in materials scien ce [1, 2] and environmental chemistry and medicine. Schiff- base compounds p lay a vital role in coordin ation chemistry , due to t heir ability to react with a range of metal ions forming st able complexes which have app lications in different fields. One interesting app lication in the field of coordination chemistry has been to invest igate the use of Schiff-base ligands to develop p henoxo-bridged binuclear comp lexes with homometallic and/or h eterometallic centres. This includes design molecules containing p aramagn etic metal centres are able to self-assemb le through metal- ligand interactions rendering sup ramolecular assemblies with interesting st ructural and magnetic p rop erties. [3- 7]. Schiff-b ase metal complexes also have app lications in biomedical [8, 9], biomimetic and cataly tic syst ems [10, 11]. Oxime chemistry is one vital research field for inorganic and bioinor ganic chemist. The role of o ximes and their metal complexes, in p articular cobalt- oximes, in the biological sy st ems make them on e interested branch in the coordination and organometallic chemistry . Significant p ublications dealt with t he develop ment of coordination chemist ry are related to the p rep aration and charachterisation of oximes and their metal comp lexes. These includ e the invest igation of n ew sy nthetic methods and coordination modes of oxime sp ecies up on comp lexation [12]. It is well known that oxime and o ximato sp ecies can bind a metal in different coordination modes. Gup ta et al. [13] rep orted a simple and general route to the sy nthesis of organo-cobalo ximes with mixed dioxime ligands of the general formula, [RCo(L)(dpgH)py ] (where: L= dmgH and ChgH; R= M e–Decane: DmgH= dimethy l glyoxime; Ch gH= 1,2–cyclohexanedioneglyoxime). The mode of bonding was invest igated throu gh p hy sico-chemical and sp ectroscop ic methods. X–ray cry stal structures confirmed the prep aration of six-coordinate cobal-oxime comp lexes. It is well do cumented that o xime compounds and their complexes with transition metals hav e many applications in medicine, biology , industry , and cataly sis [14]. Recently, we reported the formation of p olymeric chain assemblies of some p henoxo-bridged binuclear transition metal ions with the mutidentate Schiff-base (E)-6,6`-((1E,1`E)-(ethane-1,2-diy lbis(azan-1-yl- 1-y lidene))bis(methan-1-yl-ylidene))bis(4-methy l-2-((E)(py ridine-2-ylmethy limino)methy l) p henol). The ligand h as been sp ecifically design ed in which the involvement of the p y ridy l moieties p lay ed effective role in ensuring the formation of ladder-ty p e structures [15]. As p art of our continuing efforts to exp lore the use of multidentate Schiff-b ase ligands for the sy nthesis of new comp lexes, we describ e here the sy nthesis and sp ectral invest igation of som e p henoxo-bridged binu clear transition metal ions with t he new multidentate oxime- Schiff-base IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 ligad namely (1E,1`E)-2hy droxy -3-((E)-(2-((E)-2-hy drxy 3-((E)-(hy droxy imino)methy l)-5- methy lbenzyldeneamino)ethy limino)methy l)-5- methy lbenzaldehyde oxime H4L. Experime ntal Materials and methods All reagents were obtained commercially (Aldrich) and used without further purification. Solvents used in the sy nthesis were dist illed from app rop riate dry ing agent immediately p rior to use. 2,6-Diformyl-4-methy l-p henol was p rep ared by a method p ublished in [16]. Physi cal measurements Elemental analy ses (C, H and N) were carried out on a Heraeus instrument (Vario EL). IR sp ectra were recorded as KBr or CsI discs using a Shimadzu 8300 FT IR sp ectrop hotometer from 4000-250 cm -1 . M elting p oints were obtained on a Bu chi SM P-20 cap illary meltin g p oint app aratus and are uncorrected. Electronic sp ectra were measured from 200-900 for 10 -3 M solutions in DM F at 25C using a Shimadzu 160 sp ectrop hotometer. M ass spectra obtained by p ositive Electron Impact (EI) record ed on a VG autosp ec micromass sp ectrometer. M etals were determined usin g a Shimadzu (A.A) 680 G atomic absorption sp ectrop hotometer. Conductivity measurements were made with DMF solutions using a Jenway 4071 digital conductivity meter and room temp erature magn etic mo ments were measured with a magn etic susceptibility balance (Jonson M attey Cataly tic Sy stem Division). S ynthesi s Prep aration of the p recursor (E)-2-hydroxy -3-((hy droxy imino)methy l)-5- methy lbenzaldehyde To a mixture of 2,6–diformy l–4–methy l p henol (5.0 g, 30.0 mmol) dissolved in ethanol (5 mL) was added a mixture of hy droxy lamine hy drochloride (2.12 g, 30.0 mmol) in H2O (15mL). The mixture was st irred, and then cooled to (–5C). An aqueous solution of sodium hydroxide (20 %) was added slowly , and the temperature was kep t below (0 C) with vigorous st irring 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 p H. The solid was collected by filtration, washed with benzene and air dried, to give (3.25 g, 60%) of the title comp ound, m.p. = 142C. IR data (cm -1 ): 3238 ν(O– H)oxime, 3310 ν(O–H)p henol, 1637 ν(C=O), 1604 ν(C=N), 1265 ν(C–O), 1060 ν (N–O). IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 Preparation of the S chiff-base H4L A solution of ethy lenediamine (0.5 g, 8.0 mmol) in methanol (10 mL) was added slowly to a mixture of the p recursor (3.0 g, 16 mmo l) 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 co llected by filtration, recry st allised from a mi xture of hot methanol/ H2O (1:1) and dried under vacuu m 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)p henolic; 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(p henoxide) and 2374 ν(H–O … H). The p ositive EI mass sp ectrum of H4L showed the followin g fragments; 338 (5 %) [M –(CH=N–OH)] + , 231 (3 %) [M –(CH=N–OH–C6H2–M e– OH)] + , 214 (64 %) [M –{CH=N–OH–C6H2–M e–(OH)2}] + , 186 (12 %) [M –{CH=N–OH– C6H2–M e–(OH)2–N=CH}] + , 132 (3 %) [M–{CH=N–OH–C6H2–M e–(OH)2–N–CH–(CH2)2– N=CH}] + , 89 (5 %) [M –{CH=N–OH–C6H2–M e–(OH)2–N=CH–(CH2)2–N=CH–CH=N– OH}] + . General synthesis of the complexes A solution of the Schiff-base (1 mmo l) and p otassium 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 drop wise. The resulting mixture was refluxed under N2 for 2 h, resulting in the for mation of a solid mass which was washed several times with methanol (10 mL), and then ether (15 mL). Elemental analy sis data, colours and y ields for the comp lexes are given in (Table 1). Mole cular modelling 3D molecular modellin g of the prop osed structure of the complexes was p erformed using CS Chem 3D Ultra M olecular M odellin g and Ana lysis Program [17]. It is an interactive graphics p rogram that allows rapid st ructure building, geometry optimization with minimum ener gy and molecular disp lay . It is well known p rogram and has the ability to handle transition metal comp lexes [18]. The correct st ereochemistry was assured through the manipulation and modification of the molecu lar coordin ates to obtain reasonable low energy molecu lar geometries. IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 Results and Discussion The p recursor (E)-2-hydroxy -3-((hy droxy imino)methy l)-5-methy lbenzaldehyde (Scheme 1 A) was obtained by condensation reaction using one equivalents of 2,6-diformy l- 4-methy l-p henol and one equivalent of hy droxy l amine hy drochloride. The IR sp ectrum of the p recursor showed characterist ic bands due to the ν(O-H) oxime and ν(O-H) p henol, ν(C=O), ν(C=N), ν(N-O), and ν(C=C) functional group s. The reaction of ( E)-2-hydroxy -3- ((hy droxy imino)methy l)-5-methy lbenzaldehyde with ethy lenediamine in mole ratios of 2:1, resp ectively afforded the new Schiff-base o xime (1 E,1`E)-2hy droxy -3-((E)-(2-((E)-2- hy drxy 3-((E)-(hy droxy imino)methy l)-5-methy lbenzy-ldeneamino)ethy limino)methy l)-5- methy lbenzaldehyde oxime H4L in moderate y ield (Scheme 1B). S cheme 1: Chemical structures of precursor and S chiff-base oxime ligand The Schiff-base o xime was characterised by elemental analy sis (Table 1), IR (Table 2), UV–Vis (Table 3) sp ectroscopy and mass sp ectrometry . The IR sp ectrum of the free Schiff- base shows characterist ic 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 group s, resp ectively. The sp ectrum showed also abroad band at 3310 cm –1 assign ed to the ν(O–H) st retching of the p henol group . The weak bands app eared around 2374 and 1762 cm –1 are due to the ν(H– O  H) stretching and (H–O … H) bending indicatin g the p resence of the hy drogen bonding in the molecule. The UV-Vis sp ectrum of H4L IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 exh ibits an intense absorp tion peak at 285 nm, assign ed to    * . The p eak at 350 nm assigned to n → π* transition. The mass sp ectrum does no show t he parent ion fragment (M ). This may be due t o the harsh cond ition (EI technique) used to obtain the sp ectrum. The mass sp ectrum was consistent with the prop osed st ructural formula. Figure 1 shows the EI sp ectrum of the ligand, while the fragmentation pattern of the ligand disp lay ed in scheme 2. S cheme 2: Mass fragmentation pattern of the S chiff base oxime ligand The bridged p henoxy binuclear comp lexes of the ligand with M n II , Fe II , Co II and Cu II were sy nthesised by heating 1 mmole of the ligand with 2 mmole of the metal chloride in methanol usin g p otassium 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 p otassium hydroxide, deprotonation of the ligand occurs fa cilitating the formation of the comp lexes [M II 2(HL)](Cl).H2O (M = Mn(II), Fe(II), Co(II) and Cu(II)) (Scheme 3). The comp lexes are air-st able solids, solub le in DM F but not in other common or ganic solvents. The coordination geometries of t he complexes were deduced from their sp ectra. IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 The analytical data (Table 1) agree well with the su ggested formulae. Conductivity measurements of M n(II), Fe(II), Co(II), Cu(II), Cd(II) and Hg(II) comp lexes lie in the 54.6- 77.9 cm 2 Ω -1 mol -1 range, indicating their 1 :1 electrolytic behavior (Table 1) [19]. S cheme 3: Propose d structures of binuclear S chiff-base oxime ligand The important infrared bands for the complexes to gether with their assi gnments are list ed in Table 2. The IR sp ectra of the comp lexes exhibited H2L bands with the approp riate shifts due to comp lex formation (Table 2). The absence of a p eak around 3310 cm -1 in all the comp lexes indicate the absence of p henolic ν(OH) due to dep rotonation followed by comp lexation [20]. The ν(C=N)imine and ν(C=N)oxime st retching bands at 1637 and 1575 cm -1 , resp ectively in the free Schiff-base is shifted to lower frequency and observed around 1610- 1629 cm -1 and 1496-1560 for the comp lexes. The bands are assi gned to a ν(C=N) st retch of reduced bond order. This can be attributed to delocalisation of metal electron density (t2g) to the π-sy stem of the ligand [21, 22], indicating coordination of nitro gen of the C=N moieties to the metal atoms [23]. Furt her, bands in the region of 1527–1558 cm -1 in all the comp lexes suggest p henoxide bridging with the metal atoms [15, 24]. The st rong ν(N–O) st retching bands at 1039 and 1020 cm –1 in the free li gand are shifted to hi gh er frequ encies and app eared at 1085-1184 and 1033-1160 cm –1 for the co mplexes. The increase in the N–O bond order can be attributed to the dist ribution of the -electron of the oxime moiety up on comp lex formation IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 [25]. It seems that t he 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 comp lexes exhibited bands around 410–450 and 536–581 cm -1 whi ch cou ld be assign ed to ν (M –N) and ν(M –O) vibration modes, resp ectively [15, 21]. Due to the lar ger dipole moment chan ge 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 assi gned to ν(H–O … H) and (H– O … H), resp ectively. The broad band observed around 34800-3527 cm -1 assi gned to (H2O) lattice molecule [28]. The electronic sp ectra and magnetic moment data of the dimeric comp lexes are summarised in (Table 3). The electronic sp ectra of the comp lexes M n(II), Fe(II), Co(II) and Cu(II) exhibit a high intensity p eak around 299-355 nm related to the intra- ligand field transition. The electronic sp ectrum of the M n(II) comp lex showed additional p eaks at 315 and 396 nm assigned to t he charge transfer (CT) and d–d transitions, resp ectively in a distorted tetrahedral geometry [29, 30]. The observed magn etic moment of this comp lex is typical for a terahedral st ructure. The electronic sp ectrum of the Fe(II) comp lex is consistent with tetrahedral assign ment [29, 31]. The magnetic moment of this comp lex is typical for tetrahedral st ructure. The sp ectrum of the Co(II) comp lex exhibited two bands characterist ic of tetrahedral Co(II) comp lexes [29-32]. The magnetic moment was consistent with the tetrahedral environment around Co(II). The magn etic moment valu e (Table 3) observed for the Cu(II) comp lex agrees well with the prop osed square p lanar geometry . The electronic sp ectrum of the Cu(II) comp lex shows a broad band which can be attributed to 2 B1g → 2 B2g transition, corresp onding to square planar geometry [29, 33]. The magnetic moment values for the binuclear comp lexes at RT are lower than the p redicted valu es. This may arise from metal– metal interactions through the p henolic o xy gen atoms and/or extensive electron delocalisation, which may be related to t he formation of dimeric st ructures [34, 35]. Dmolecular modelling and analysis of bonding modes M olecular mechanics att empts to reproduce molecular geometries, ener gies and other features by adjust ing bond len gth, bond angles and torsion angles to equilibrium valu es that are dependent on the hy bridization of an atom and its bonding scheme. In order to obtain estimates of structural details of these comp lexes and in view the four-coordination of all the comp lexes, we have op timized the molecu lar st ructure of [Co II 2(HL)](Cl)(H2O) as a representative comp ound (Figure 2). The details of bond lengths and bond angles p er the 3D molecu lar st ructure are given in Tables 4. Ener gy min imization was r epeated several t imes to find the global min imum [36]. The energy minimization value for tetrahedral and without restricting the st ructure for the Co-comp lex is almost same i.e, 560.8472 Kc al /mol. The molecu lar modelling for the modulated Co(II)-co mplex (f igure 2 and Table 4) shows t he bond IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 len gths bond angles around copp er atom which indicate the distorted tetrahedral geometry around Co(II) ion [37], and thus the prop osed structure of the Co(II)-complex as well as of t he others, are accep table. Conclusion In this p ap er, we have exp lored the sy nthesis and coordination chemist ry of some binuclear comp lexes d erived from the multidentate Schiff-base o xime ligand H4L. The ligand behaves as a tribasi c octadentate sp ecies up on comp lexation with the involvement of the nitrogen atoms of the o xime group s in coordination for all comp lexes. The low magn etic moment values of these comp lexes are in accord with the formation of p henoxy -bridged binuclear metal comp lexes. Re ferences 1. Lehn, J.M . (1995) Sup ramolecular ch emistry concepts and persp ectives, 1st edn. Wiley - VCH, Weinh eim 2. Belghoul, B.; Welterlich, W.; M aier, A.; Tout ianoush, A.; Rabindranath, A.R.and Tieke, B. (2007) Lan gmuir, 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) Inor g. Chem. 49 : 9902-9908. 6. Yesiel, O. Z .; Erer, H., Kast as, G., Kani, I., Poly hedron, 29: (2010) 2600-2608. 7. Habib, H.A.; Gil-Hernandez, B.; Abu-Shand i, 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’T ahlil-Buhuth Wadirasat, 19: 89. 10.Cost amagna, J., Ferraudi, G., M atsuhiro, B., Vallette, M .C., Canales, J., Villagra’n, M ., Vargas, J., Agu irre, M .J., Coord. Chem. Rev., 196 (2000) 125. 11. Coughlin, P.K., Lipp ard, 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. Gupt a, 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. So c., 94 (1972) 727. 15. Al-Jeboori, M .J., Hasan, H.A., Al-Sa’idy , W.A. J, Transition M et. Chem., 34 (2009 ) 593–598. IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 16. Veran i, C.N., Rentschler, L., Thomas, W., B ill, E., and Ch audhuri, P., J. Chem. Soc. Dalton T rans., (2000) 251. 17. CS Chem 3D Ultra M olecular M odeling and Analysis, Cambridge, www. cambrid gesoft.com. 18. M aury a, R.C., Rajput, S., Journal of M olecular Structure, 794 (2006) 24.34. 19. Geary W.J., Coord. Chem. Rev., 7(1971) 81. 20. Sarav anakumar, D., Sengottuvelan, N., Priy adarshni, G., Kandaswamy, M ., Okawa, H., Poly hedron, 23 (2004) 665. 21. Al-Jeboori, M .J., Al-Dujaili, A.H. and Al-Janabi, A.E., Transition M et. Chem., 34 (2009) 109. 22. Livingst on, S.E., M ayfield, J.H., M oorse, D.S., Aust. J. Chem., 28(1975) 2531. 23. El-Sonb ati, A.Z ., El-bindary A.A., Al-Sarawy , A.A., Sp ectrochim Acta Part A, 58 (2002) 2771. 24. Sreed aran, S., Bharathi, KS., Rahiman, A.K.,, Rajesh, K., Nirmala, G., Jagadish, L., Kaviyarasan, V., Narayanan, V., Poly hedron, 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 & App l. Sci., vol. 18, No. 2 (2005) 51–67. 27. Nakamoto, K., and Ohkaku, N., Inorg. Chem., 10 (1971) 798. 28. Nakomoto, K., Infrared Sp ectra of Inorganic and Coordination Compounds, (1996) 4 th ed., J. Wiely and Sons, New York. 29. Lever, A.B.P., (1984) Inor ganic Electronic Sp ectroscopy , 2nd edn., Elsevier p ublishing, New York. 30. Figgis, B.N., (1967) Introduction to Ligand Fi elds, Interscience Publ ishers, 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 Ay id, K., American Journal of App lied Sciences, 6 (4) (2009) 582-585 34. Okawa, H.; Tadokora, M .; Aratake, T.Y.; Ohba M .; Shindom, K.; M itsumi, 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., M oon, S-T., Kim, J., Han, S.W., Park, K-M ., Lindoy , L.F., and Lee, S. S., (2005) Dalton T rans., 788. IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 36. M ishra, A P.; M ishra, R.K. and Shrivast ava, S.P. (2009) Journal of t he Serbian Ch emical Society , 74: 523.535. 37. Børst ing, P. and Steel, P.J. Eur. (2004) J. Inor g. Chem., 376-380. Table(1): Colours, yields, elemental anal yses, and molar conductance values. Compound Colour Yield (%) m.p ºC Found (Calcd.) (%) M(cm 2 Ω -1 mol -1 ) M C H N Cl H4L Light brown 59 165 - 62.9 6.3 14.2 - - (62.8) (5.6) (14.6) [Mn II 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) [Co II 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) [Cu II 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) im inic ν( C=N) oxim e ν( Phenoxide ) ν( N-O) ν( H–O … H) ν( M-O) ν( M- N) H4L 1637, 1929 1575, 1565 1373 1039, 1020 2374 - - [Mn II 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. S CI. VOL. 24 (2) 2011 Table(3): Magnetic moment and u.v-vis spectral data in DMF sol utions. Compound ef f (BM ) Band position Extinction coefficient Assignments (p er atom) ( nm) m ax(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 4 T1g (F) → 4 T1g (P ) 678 281 4 T1g (F) → 4 A2g (F) [M n II 2(HL)](Cl).H2O 4.9 297 780 Ligand field 366 1100 CT 414 101 6 A1g  4 T1g [Fe II 2(HL)](Cl).H2O 5.2 355 644 Ligand field 375 388 CT 418 200 5 E2 (D)  5 T2 (D) [Cu II 2(HL)](Cl).H2O 1.46 299 1500 Ligand fied 383 478 CT 650 250 2 B1g → 2 A1 g ___________________________________________________________________________ Table(4): Propose d bond le ngths and bond angles of [Co2(HL)](Cl )(H2O). Type of bond Bond len gths(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) = Angst rom () = Degree IBN AL- HAITHAM J. FOR PURE & APPL. S CI. VOL. 24 (2) 2011 Fig.(1): (EI) mass spectrum of the S chiff-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 ـــــائي [ ــــ ــــي -2(ثنـــ ــــ ــــ ــــیم -3-هایدروكسـ ــــ ــــ ـــل أوكسـ ــــ ــــ ــــد -5-فورمایــ ــــ ــــ ــــل بینزیالدأمایـ ــــ ـــروجین -)میثــــ ــــ ــــ ــــاث -نتــ ــــ ــــ ) H4L(ینیلـ الكوبلت(ومعقداتها ثنائیة النواة مع )II( ، المنغنیز )II( ، الحدید )II( ، النحـاس )II( diformy 2,6تـم تحضـیرالیكاند بمفاعلـة) . l– 4–methy l phenol مع hy droxy l amine hydrochloride .1:1وبالنسبة المولیة 2-hydroxy-(E)لیعطي المشتق -3-((hy droxy imino)methy l)-5-methy lbenzaldehyde (H4Lلیعطـي الیكانـد االوكسـیمي نــوع 2:1فـي الخطـوة االخیـرة تــم مفاعلـة المشـتق مـع االثلــین داي امـین وبالنسـبة المولیــة N4O2(عنـد تكـوین المعقــد یكـون الیكانــد ثالثـي القاعدیــة سداسـي المـنح)واشـكال المعقــدات تـم تعینهــا طبیعـة التأصــر ).الســن ــــة ــــالطرق الطیفیةوالفیزیاویـ ــــدات .بـ الكوبلـــــت(اعطـــــت هـــــذه الدراســـــات التناســـــق الربـــــاعي الســـــطوح لمعقـ )II( ـــز ، المنغنیـــ )II( ، الحدید )II( :وشكل المربع المستوي حول ایون النحاس وبالصیغة العامة التالیة) [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