IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Synthesis and Characterization of Tetradentate Complexes Type N2O2 From the Reaction of 2-Hydroxy -1, 2-Diphynel-Ethanone Oxime [H2L] With Mn II, Fe II, Co II, Ni II, Cu II and Hg II Ions A.Th. Numan*, E. I. Alsalehe and J. H. Aldulaimi Department of Chemistry, College of Education, Ibn Al-Haitham, University of Baghdad Abstract Tetradentate complexes type [M (HL) 2] were prepared from the reaction of 2-hydroxy -1, 2-diphynel-ethanone oxime [H2L] and KOH with ( Mn II, Fe II, Co II, Ni II , Cu II and Hg II ), in methanol with (2:1) metal: ligand ratio. The general formula for Cu II and Mn II complexes are [M (HL) 2 Cl.H2O] K, for Co II [Co (HL) 2. H2O] and [M (HL) 2] for the rest of complexes. All compounds were characterised by spectroscopic methods, I.R, U.V-Vis, H.P.L.C, atomic absorption and conductivity measurements chloride content. From the data of these measurements, the proposed molecular structures for Fe II and Hg II complexes are tetrahedrals, while Mn II and Cu II complexes are octahedrals, Ni II complex adopting square planar structure and the complex of Co II ion showed a bipyramidal structure Introduction Amino oxime metal complexes have been known since a long time (1). The different coordination modes of oxime and oximato species indicated a versatile electronic distribution within the ligand. This, in turn suggested that the chemistry of metal-bonded oximes should be rich. The inspection of data accumulated in the literature confirmed these assumptions (2).Transition metal complexes of vic- dioximes are of particular interest as biological model compounds. Numerous chemical studies have been made on the cobalt (III) –bis (dimethyl glyoxime) system which has been called a model system for B12 moiety (3,4). Although these efforts metl with a considerable success. There are some species which do not appear to behave according to the existing theories (i.c., the dioxime of glyoxal). It was felt that stability constant studies would be of value in showing the inherent differences in the chelating ability of closely related metal ions (5). The synthesis of some cobalt (III) dioxime complexes with ligands containing macrocyclic frame on the backbone was reported (6,7). The template synthesis of these compounds involve linking of two tetraazamacrocycle containing components through dioxime coordinate to Co(II) then an aerial oxidation of this ion to Co(III)is done in the presence of (axial coordinating) pyridine and chloride ligands, (Fig. A). (Fig-A) IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 This paper reports the synthesis and characterisation of new complexes derived from the reaction of [2-hydroxy -1, 2-diphynel-ethanone oxime] with (M n II, Fe II, Co II, Ni II , Cu II and Hg II) metal ions. Experimental Reagents were purchased from Fluka and Redial – Dehenge Chemical Co. I.R spectra were recorded as (KBr) discs using a Shimadzu 8300 FTIR spectrophotometer in the range (4000-400) cm-1. Electronic spectra of the prepared compounds were measured in the region (200-1100) nm for 10-3 M solutions in (DM F) at 25C using a Shimadzu 160 spectrophotometer with 1.0000.001 cm matched quartz cell ,while metal contents of the complexes were determined by atomic absorption (A.A) technique using a Shimadzu AA 680G atomic absorption spectrophotometer. Electrical conductivity measurements of the complexes were recorded at 25C for 10-3 M solutions of the samples in (DMF) using a PW 9526 digital conductivity meter. The H.P.L.C. chromatograms of the complexes were obtained using H.P.L.C. type shimadzu LC-6H (Koyoto–Japan) in an isocratic system (MeCN: H2O), (70–30). as a solvent. Synthesis of [Mn (HL) 2 .Cl.H2O] K A 0.25g, (1.26mmole) of MnCl2.4H2O was dissolved in 10ml methanol. A solution of 0.56g, (2.46mmole) of [H2L] in 10ml ethanol was added to the above mixture. Then of KOH dissolved in methanol and added to the above mixture. The reaction was refluxed for 2 hrs and during thes time, the colour of the mixture became brown. The solution was allowed for slow evaporation and a brown precipitate was formed. Yield 0.62g (43 %), m.p 255C. Synthesis of [Fe (HL) 2] The method used to prepare [Fe (H2L2)] was analogous to the procedure given for the complex [Mn (HL) 2.Cl.H2O] K, but with FeCl2.4H2O 0.25g, (1.25mmole) instead of MnCl2.4H2O. The quantities of the other regents were adjusted accordingly and an identical work-up procedure gave red purple precipitate 0.76g (60%), m.p 175C. Synthesis of [Co (HL)2.H2O ] In 50 ml round bottomed flask 0.25g, (1.05mmole) of CoCl2.6H2O was dissolved in 10ml methanol. A solution of 0.572g, (2.09mmole) of [H2L] in 10ml ethanol was added to the above mixture, and the reaction was allowed to reflux for 2 hrs. The pale brown precipitated solid which formed upon standing over 24 hrs, was collected, washed with 2ml ether, and dried to give 0.88g (80%) of the title compound, m.p 190 C. Synthesis of [Ni (HL) 2] A similar procedure to that described for the complex [Co(HL)2.H2O] was used to prepare [Ni(HL)2)] but with NiCl2.6H2O 0.25g, (1.05mmole) in place of CoCl2.6H2O with 0.478g, (2.10mmole) [H2L] to give an orange precipitate ,which was washed with 2 ml ethy l ether to yield 0.60g (56%) m.p 165C. Synthesis of [Cu (HL) 2. Cl.H2O] K A 0.25g of CuCl2.2H2O, (1.46mmole) was dissolved in 10 ml ethanol. A solution of 0.666g, (2.90mmole) of [H2L] in 10ml methanol was added and allowed to reflux for 2 hrs. A deep green precipitate was formed, washed with 2 ml ether in order to give 0.68g (31%) m.p 240C. IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Synthesis of [Hg (HL) 2] The method used to prepare [Cu (H2L2) Cl.H2O] was analogous to the procedure given for the complex [Hg (H2L2)] but with HgCl2. (0.25g, 0.92mmole) instead of CuCl2.2H2O.The quantities of the other regents were adjusted according to an identical work-up procedure in order to give a mustard precipitate (0.57g) (48%), m.p 135C. Results and Discussion The I.R spectrum for (H2L) ligand (Fig.2A), displayed aband at 1491 cm 1- due to the υ C=N stretching frequency for the oxime group (8). The band at 3233 cm -1 is attributed to the υ O─H stretching of the oxime group. The strong bands at 1014 and 986 cm-1 are attributed to υ N─O stretching. While U.V-Vis aspectrum (Fig.3A) exhibits a high intense absorption peak at 278 nm, 35971 cm-1, maxε =1570 M -1 .cm-1 and 300nm, 33333cm -1 , maxε =1514M -1 .cm-1 which were assigned to overlap → *and n → * transitions(9). The reaction of [H2L] ligand with the metals (Mn II , Fe II , Co II , Ni II, Cu II and Hg II ) was carried out in methanol under reflux. All complexes are stable in the solid state and in the solution. The analytical and physical data (Table-1) and spectral data (Table-2 and 3) are compatible with the suggested structures (Fig.1). The I.R spectral data of the complexes are presented in (Table -2). These spectra, in general show bands at the range 1552-1599 cm -1 assigned to the υ C=N stretching for the oxime groups. The shifting to a higher frequency is made in comparison with that of the free ligand, this shifting can be attributed to the delocalisation of metal ion electronic density into the ligand (- system) (10, 11). The strong υ N─O stretching bands at 1014 and 996 cm-1 for the free ligand are shifted markedly to higher frequencies by ca. 100 cm -1 . This is presumably due to coordinated N─O group with the metal ions (12). These results are in agood agreement with those reported by Bigatto and co-workers (13). The υ O─H stretching band of the oxime group in the free ligand at 3233 cm -1 is still present at the (3025-3459) cm-1 rang for these complexes. The bands at 635-523 cm-1and 494-635 cm-1 were assigned to υ M─N and υ M─O stretching, indicating that the oxime nitrogen and oxygen of hydroxyl group were involved in coordination with metal ion (14-16). The bands at the range 630-660 cm -1 , 732-760 cm -1 and 829-919 cm -1 in the I.R. spectra of complexes Mn, Co and Cu respectively are attributed to υ O─H stretching frequency for coordinated H2O molecules with metal ion (17). Fig (2B), (2D and (2F) represent the I.R spectra for the complexes Mn, Co and Cu respectively. The electronic spectral data of the complexes are summarised in (Table-3). The U.V-Vis spectra of the complexes displayed absorptions at 275-344 nm assigned to the ligand field and charge transfer (18). In the [Mn (HL) 2 .Cl.H2O] K and [Cu (HL)2.Cl.H2O] K complexes the peaks at 500nm and 432nm are attributed to d -d electronic transitions type 4Eg(G)← 6A1g and 2B1g← 2B2g respectively , suggesting an octahedral structure about Mn and Cu ions. The peak at 855nm in the spectrum of [Fe (H2L)] (Fig.3C) is assigned to (5T2← 5E (d -d) electronic transitions, suggesting tetrahedral structure about Fe ion. In the U.V-Vis spectrum of [Ni (HL) 2] (Fig.3E), the peak at 747 nm is attributed to (d-d) electronic transition type 3T1 (p) ← 3T1suggesting asquare planar structure about Ni ion. The U.V-Vis spectrum of [Hg (HL)2] suggests asquare planar structure about Hg ion too. While the peak at 400 nm in the spectrum IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 of the [Co (HL) 2) H2O] is attributed to (d-d) electronic transition type 4 E (F) ← 4 A2 suggesting a trygonal bipyramidal structure about Co ion [18]. The molar conductance of the complexes in DM F lies in the 22.9─5.22 ohm-1.cm2.mole-1range (Table-3) indicates the complexes that are to be neutral (Mn and Cu complexes are electrolyte with 1:1 ratio) (19). The H.P.L.C chromatograms for these complexes [Mn (HL) 2) Cl.H2O] K, [Fe (HL) 2] and [Co (HL) 2H2O] Figs. (4-a, b, c) respectively, exhibit one signal at aretention time (tR= 2.8 min), (tR= 3.4 min) and (tR= 4.6 min) indicate the purity of the complexes and appear as a single species in a solution. References 1. Murmann,R.K. (1957) J. Am. Chem. Soc., 79: 521, 2. Kukushkin ,V. Yu. et al(1996) Coordination Chemistry Reviews 156 :333-362, 3. Finke,R. G .; Schiraldi, D. A. and Mayer,B . (1984).J. coord. Chem. Rev., 54: 1 4. Schrauzer, G. N. (1968) Accounts chem. Res., 1:97 5. Gok, Y. and Kantchin,H. (1997).Polyhedron, 16:2413 6. Gok, Y. and Kantckin,H. (1997) Acta. Chem. Scand., 51:664 7. Kemp,W. (1987)."Organic Spectroscopy" 2nd. Edition, 144, 8. Hadzi, D. and Premru, L. (1967) Spectrochim. Acta, 23A, 35, 9. Abdul-Rahman, A. A. (2002). Ph D. Thesis, Collage of Education Ibn- Al-Heaitham University of Baghdad 10. Hadzi,D. (1956) J. Chem. Soc., 15: 2725, 11. Bigatto,A. ;Costa,G.; Galasso V. and Dealti,G. (1939), (1970) Spectrochim. Acta, 26, 12. Nakamoto ,K. (1996) “Infrared Spectra of Inorganic and Coordination Compounds”4 th. Ed. J. Wiely and Sons, New York, 13. Ferraro,J. (1971) “Low Frequency Vibrations of Inorganic and Coordination Compounds ” Ed. Plenum, New York, 14. Najappan, P. ; Ramalingam, K.; Pirro, S. J.; Narr, R. K.; Nowotinik ,D. P.; Nunn, A. D. (1992).Abstracts of papers, Ninth International Symposium on Radiopharmaceutical Chem. Paris 6-10 April 15. EL-Tabl, A. S. (2002)Transition Metal Chemistry, 27:166, 16. Geary,W. J. (1971) Coord. Rev., 7: 81, 17.Green Wood, N.N. and Earnshow,A. (1998)Chemistry of the Elements, Ed. J. Wiley and Sons Inc. New York, 18.A. B. P. Lever, “Inorganic Electronic Spectroscopy”, Ed. New York, (1968). 19.Geary, W. J. (1971) “The use of conductivity measurements in organic solvents for the characterization of coordination compounds”. Coord. Chem. Rev; 7:(81-115) IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Table (1): Analytical and physical data of the ligand and its complexes (Calc.): calculated Found, (Calc.)% Yiel d % m. p C Colou r Molecu lar weight M.W Compound Metal Cl - ------- white 227.27 [H2L] (9.15) 9.00 (5.93) 4.86 43 Brow n 599.94 [Mn(HL)2Cl.H2O)] K (10.97 ) 10.50 ------ 60 17 5 Red purple 508.34 [Fe(HL)2] (11.12 ) 10.90 ------- 80 19 0 Pale Brow n 529.54 [Co(HL)2 H2O] (11.47 ) 11.21 ------- 56 16 5 Orang e 511.34 Ni(HL)2] (10.43 ) 10.11 (5.84) 3.44 31 24 0 deep green 608.54 [Cu(HL)2Cl.H2O]K (30.71 ) 30.53 ------- 48 13 5 musta rd 653.14 [Hg(HL)2] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Table (2): I.R spectral data of the ligand and it’s complexes s: strong m: medium w: weak br: broad w.br: weak broad Table (3): Electronic spectral data, HPLC and conductance measurements of [H2L] and its complexes Compound (O-H) oxime (O-H) H2O (C-H) aliph (C-H) aroma (C=N) oxime (N-O) (M-N) (M-O) Additional peaks [H2L] 3233(b) _ 2920(w) 3023(w) 1491(sh) 996(sh) 1014(sh) _ 1387 (CH2) 1590 (C=C)ring [Mn(HL)2Cl.H2O)]K 3350(w) 3249(w) 2925(w) 3057(w) 1552(s) 987(s) 1013(s) 523(w) 501(sh) 1491(C=C) ring [Fe(HL)2] 3342(br) 2910(w) 3075(br) 1597(sh) 988(s) 1015(s) 591(s) 479(br) 1491(C=C) ring [Co(HL)2H2O] 3459(w) 3250(w) 2915(br) 3060(br) 1598(sh) 1001(w) 1066(s) 657(sh) 537(w) 1492(C=C ring [Ni(HL)2] 3416(w) 2905(br) 3052(br) 1599(br) 1019(w) 1068(br) 695(sh) 635(w) 1492(C=C)ring [Cu(HL)2Cl.H2O]K 3379(br) 3233(w) 2881(w) 3057(br) 1595(s) 1004(s) 1045(w) 597(br) 511(br) 1577(C=C)ring [Hg(HL)2] 3025(w) 2950(w) 3025(w) 1567(s) 1013(br) 1110(br) 623(w) 494(sh) 1500(C=C)ring Compound  nm max M -1 . cm - 1 assignments M.C* (ohm1.c m 2 . mole-1) (HPLC) Min. solvent Ratio [H2L] 278 1570 (→ *) (n → *) ------- ------- 300 1514 [Mn(HL)2Cl.H2O)]K 275 551 (4Eg(G)← 6A1g) 53 2.8 DMF 1:1 340 112 500 17 [Fe(HL)2] 300 2352 (5T2←5E) 15.43 3.4 DMF neutral 342 2127 384 1188 855 4 [Co(HL)2 H2O] 314 2436 ( 4 E(F)← 4 A2) 22.9 4.6 DMF neutral 400 1700 879 5 [Ni(HL)2] 300 1796 ( 3 T1(p) ← 3 T1) 12.45 ------ DMF neutral 344 1809 469 1014 747 2 [Cu(HL)2Cl.H2O]K 297 1477 ( 2 B1g← 2 B2g) 54 ------ DMF 1:1 432 461 [Hg(HL)2] 292 450 1154 125 C.T 5.22 ------- DMF neutral IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Scheme (1): The synthesis route of the complexes Where X=Mn II and Cu II; and Y=Ni II and Hg II Fig. (1): The suggested structures for the complexes CH C HO N OH MCl 2 CH O N OH CH O N OH M + ! m o l e 2 - H y d r o x y - 1 , 2 - d i p h e n y l - e t h a n o n e o x i m e 2 m o l e IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Fig. (2-A) :The (I.R) Spectra of ligand Fig. (2-B):The (I.R) Spectra of the Complex [Mn (HL)2.Cl.H2O]K Fig. (2-D): The (I.R) Spectra of the Complex [Co (HL) 2.H2O] Fig. (2-F): The (I.R) Spectra of the Complex [Cu (HL) 2.Cl.H2O] K IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Fig . (3): The (UV-Vis) Spectra of: (A) The ligand (H2L) (B) The complex [Mn (HL) 2. Cl.H2O] K (C) The complex [Fe (HL) 2)] (D) The complex [Co (HL) 2. H2O] (E) The complex [Ni (HL) 2] (F) The complex [Cu (HL) 2. Cl.H2O] K (G) The complex [Hg (HL) 2)] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Fig. (4): The H.P.L.C. chromatogram for the complexes of:- (tR= min) (a) [Ni (HL)2] complex (b) [Fe (HL) 2] complex (c) [Co (HL) 2. H2O] complex 2009) 3( 22الهیثم للعلوم الصرفة والتطبیقیة المجلدمجلة ابن من تفاعل اللیكند N2O2معقدات رباعیة المنح نوع ص یشخصتر و یحضت 2-hydroxy -1, 2-diphynel-ethanone oxime [H2L] مع االیونات (MnII, FeII, CoII, NiII, CuII, and HgII) جاسم هاشم الدلیمي،الصالحي ایمان ابراهیم ،احمد ثابت نعمان د قسم الكیمیاء ،كلیة التربیة ابن الهیثم ،جامعة بغدا الخالصة اللیكند وذلك من مفاعلةرباعیة المنح دةالجدیالمعقدات وتشخیص تضمن البحث تحضیر 2-hydroxy -1, 2-diphynel-ethanone oxime [H2L] االیونـات مـع)Mn II , Fe II , Co II , Ni II , Cu II , and Hg II) تكونــت سلســلة جدیــدة مــن ) 1:2( لیكانـد: فلــز یثــانول وهیدروكســید البوتاســیوم وسـطا للتفاعــل وبنســبةمال المعباسـت M و k [M(HL) 2.Cl. H2O] :الصیغة العامة يالمعقدات ذ *(HL) 2.H2O] وHL) 2]( [M :اذ** (Where: M=M n II , Cu II , M * = Co II , M ** = Fe II, Ni II and Hg II . االشـعة فـوق البنفسـجیة والمرئیـة ، یة االشعة تحت الحمـراءتق الطیفیة االائبوساطة الطر المحضرة تم تشخیص المركبات ، C.L.P.H ، ومـن النتـائج المحصـول علیهـاالتوصـیلیة الموالریـة الكهربائیـةومحتوى الكلـور تمطیافیـة التذریـة كـذلك قیسـو والكوبلــت ي السـطوحربــاعشـكل الحدیــد بینمـا یتخــذ معقـدهـو مربــع مسـتو زئبــق المقتـرح لمعقــد النیكـل والالفراغــي الشـكل فـان .ي السطوحثمانشكل كل من المنغنیز والنحاسوتتخذ معقدات خماسي السطوح