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 Departme nt of Chemistry, College of Education, I bn Al-Haitham, Unive rsity of Baghdad Abstract Tetradentate complexes ty p e [M (HL) 2] were prepared from the reaction of 2-hy droxy -1, 2-diphy nel-ethanone oxime [H2L] and KOH with ( M n 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 M n II comp lexes are [M (HL) 2 Cl.H2O] K, for Co II [Co (HL) 2. H2O] and [M (HL) 2] for the rest of comp lexes. All comp ounds were characterised by sp ectroscop ic methods, I.R, U.V-Vis, H.P.L.C, atomic absorp tion and conductivity measurements chloride content. From the data of these measurements, the p rop osed molecular st ructures for Fe II and Hg II comp lexes are tetrahedrals, while M n II and Cu II comp lexes are octahedrals, Ni II comp lex adopting square p lanar structure and the comp lex of Co II ion showed a bip y ramidal structure Introduction Amino oxime metal comp lexes have been known since a long time (1) . The different coordination modes of oxime and oximato sp ecies indicated a versatile electronic distribution within the ligand. This, in turn suggested that the chemist ry of metal-bonded oximes should be rich. The insp ection of data accumulated in the literature confirmed these assump tions (2).Transition metal comp lexes of vic- dioximes are of p articular interest as biological model comp ounds. Numerous chemical st udies have been made on the cobalt (III) –bis (dimethy l glyoxime) sy st em which has been called a model sy st em for B12 moiety (3,4). Although these efforts metl with a considerable success. There are some sp ecies which do not app ear to behave according to the existing theories (i.c., the dioxime of glyoxal). It was felt that st ability constant st udies would be of value in showing the inherent differences in the chelating ability of closely related metal ions (5). The sy nthesis of some cobalt (III) dioxime comp lexes with ligands containing macrocy clic frame on the backbone was reported (6,7). The temp late sy nthesis of these comp ounds involve linking of two tetraazamacrocy cle containing comp onents through dioxime coordinate to Co(II) then an aerial oxidation of this ion to Co(III)is done in the p resence of (axial coordinating) p y ridine and chloride ligands, (Fig. A). (Fig-A) IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 This p aper reports the sy nthesis and characterisation of new comp lexes derived from the reaction of [2-hy droxy -1, 2-diphy nel-ethanone oxime] with (M n II , Fe II , Co II , Ni II , Cu II and Hg II ) metal ions. Experimental Reagents were p urchased from Fluka and Redial – Dehenge Chemical Co. I.R sp ectra were recorded as (KBr) discs using a Shimadzu 8300 FT IR sp ectrop hotometer in the range (4000-400) cm -1 . Electronic sp ectra of the p repared comp ounds were measured in the region (200-1100) nm for 10 -3 M solutions in (DM F) at 25C using a Shimadzu 160 sp ectrop hotometer with 1.0000.001 cm matched quartz cell ,while metal contents of the comp lexes were determined by atomic absorp tion (A.A) technique using a Shimadzu AA 680G atomic absorp tion sp ectrop hotometer. Electrical conductivity measurements of the comp lexes were recorded at 25C for 10 -3 M solutions of the samples in (DM F) using a PW 9526 digital conductivity meter. The H.P.L.C. chromatograms of the comp lexes were obtained using H.P.L.C. ty p e shimadzu LC-6H (Koy oto–Jap an) in an isocratic sy st em (M eCN: H2O), (70–30). as a solvent. S ynthesi s of [Mn (HL) 2 .Cl .H2O] K A 0.25g, (1.26mmole) of M nCl2.4H2O 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 p recipitate was formed. Yield 0.62g (43 %), m.p 255C. S ynthesi s of [Fe (HL) 2] The method used to p repare [Fe (H2L2)] was analogous to the p rocedure given for the comp lex [M n (HL) 2.Cl.H2O] K, but with FeCl2.4H2O 0.25g, (1.25mmole) instead of M nCl2.4H2O. The quantities of the other regents were adjust ed accordingly and an identical work-up p rocedure gave red purp le p recipitate 0.76g (60%), m.p 175C. S ynthesi s 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 p recipitated solid which formed up on st anding over 24 hrs, was collected, washed with 2ml ether, and dried to give 0.88g (80%) of the title comp ound, m.p 190 C. S ynthesi s of [Ni (HL) 2] A similar procedure to that described for the complex [Co(HL)2.H2O] was used to p repare [Ni(HL)2)] but with NiCl2.6H2O 0.25g, (1.05mmole) in p lace of CoCl2.6H2O with 0.478g, (2.10mmole) [H2L] to give an orange p recipitate ,which was washed with 2 ml ethy l ether to y ield 0.60g (56%) m.p 165C. S ynthesi s 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 p recipitate 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 S ynthesi s of [Hg (HL) 2] The method used to p repare [Cu (H2L2) Cl.H2O] was analogous t o the p rocedure given for the comp lex [Hg (H2L2)] but with HgCl2. (0.25g, 0.92mmole) instead of CuCl2.2H2O.T he quantities of the other regents were adjust ed according to an identical work-up p rocedure in order to give a mustard precipitate (0.57g) (48%), m.p 135C. Results and Discussion The I.R sp ectrum for (H2L) ligand (Fig.2A), disp lay ed aband at 1491 cm 1- due to the υ C=N st retching frequency for the oxime group (8). The band at 3233 cm -1 is att ributed to the υ O─H stretching of the oxime group . The strong bands at 1014 and 986 cm -1 are att ributed to υ N─O stretching. While U.V-Vis asp ectrum (Fig.3A) exhibits a high intense absorp tion p eak 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 (M n II , Fe II , Co II , Ni II , Cu II and Hg II ) was carried out in methanol under reflux. All complexes are st able in the solid state and in the solution. The analy tical and p hy sical data (Table-1) and sp ectral data (Table-2 and 3) are comp atible with the suggested st ructures (Fig.1). The I.R sp ectral data of the comp lexes are p resented in (Table -2). These sp ectra, in general show bands at the range 1552-1599 cm -1 assigned to the υ C=N st retching for the oxime group s. 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 (- sy st em) (10, 11). The strong υ N─O st retching bands at 1014 and 996 cm -1 for the free ligand are shifted markedly to higher frequencies by ca. 100 cm -1 . This is p resumably due to coordinated N─O group with the metal ions (12). These results are in agood agreement with those reported by Bigatt o and co-workers (13). The υ O─H st retching band of the oxime group in the free ligand at 3233 cm -1 is st ill p resent at the (3025-3459) cm -1 rang for these complexes. The bands at 635-523 cm -1 and 494-635 cm -1 were assigned to υ M ─N and υ M ─O st retching, indicating that the oxime nitrogen and oxy gen of hy droxy l group were involved in coordination with metal ion (14-16). The bands at t he range 630-660 cm -1 , 732-760 cm -1 and 829-919 cm -1 in the I.R. sp ectra of comp lexes M n, Co and Cu resp ectively are att ributed to υ O─H stretching frequency for coordinated H2O molecules with metal ion (17). Fig (2B), (2D and (2F) represent the I.R sp ectra for the comp lexes M n, Co and Cu resp ectively. The electronic sp ectral data of the complexes are summarised in (Table-3). The U.V-Vis sp ectra of the comp lexes disp lay ed absorp tions at 275-344 nm assigned to the ligand field and charge transfer (18). In the [M n (HL) 2 .Cl.H2O] K and [Cu (HL)2.Cl.H2O] K comp lexes the peaks at 500nm and 432nm are attributed to d -d electronic transitions t y p e 4 Eg(G)← 6 A1g and 2 B1g← 2 B2g resp ectively , suggesting an octahedral st ructure about M n and Cu ions. The p eak at 855nm in the sp ectrum of [Fe (H2L)] (Fig.3C) is assigned to ( 5 T2← 5 E (d -d) electronic transitions, suggesting tetrahedral structure about Fe ion. In the U.V-Vis sp ectrum of [Ni (HL) 2] (Fig.3E), the p eak at 747 nm is att ributed to (d-d) electronic transition ty p e 3 T1 (p ) ← 3 T1suggesting asquare p lanar st ructure about Ni ion. The U.V-Vis sp ectrum of [Hg (HL)2] suggests asquare planar structure about Hg ion too. While the peak at 400 nm in the sp ectrum IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 of the [Co (HL) 2) H2O] is att ributed to (d-d) electronic transition ty p e 4 E (F) ← 4 A2 suggesting a try gonal bipy ramidal st ructure about Co ion [18]. The molar conductance of the comp lexes in DM F lies in the 22.9─5.22 ohm -1 .cm 2 .mole -1 range (Table-3) indicates the comp lexes that are to be neutral (M n and Cu comp lexes are electrolyte with 1:1 ratio) (19). The H.P.L.C chromatograms for t hese complexes [M n (HL) 2) Cl.H2O] K, [Fe (HL) 2] and [Co (HL) 2H2O] Figs. (4-a, b, c) resp ectively, exhibit one signal at aretention time (tR= 2.8 min), (tR= 3.4 min) and (tR= 4.6 min) indicate the p urity of the comp lexes and app ear as a single sp ecies in a solution. Re ferences 1. M urmann,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 M ayer,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 Sp ectroscop y " 2nd. Edition, 144, 8. Hadzi, D. and Premru, L. (1967) Sp ectrochim. Acta, 23A, 35, 9. Abdul-Rahman, A. A. (2002). Ph D. T hesis, Collage of Education Ibn- Al-Heaitham University of Baghdad 10. Hadzi,D. (1956) J. Chem. Soc., 15: 2725, 11. Bigatt o,A. ;Cost a,G.; Galasso V. and Dealti,G. (1939), (1970) Sp ectrochim. Acta, 26, 12. Nakamoto ,K. (1996) “ Infrared Sp ectra 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. Najap p an, P. ; Ramalingam, K.; Pirro, S. J.; Narr, R. K.; Nowotinik ,D. P.; Nunn, A. D. (1992).Abstracts of p apers, Ninth International Sy mposium on Radiopharmaceutical Chem. Paris 6-10 Ap ril 15. EL-Tabl, A. S. (2002)Transition M etal Chemist ry , 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 Sp ectroscop y ”, Ed. New York, (1968). 19.Geary, W. J. (1971) “The use of conductivity measurements in organic solvents for t he characterization of coordination comp ounds”. Coord. Chem. Rev; 7:(81-115) IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (3) 2009 Table (1): Anal ytical and physical data of the ligand and its complexes (Cal c.): calculated Found, (Calc.)% Yiel d % m. p C Colou r M olecu lar weight M .W Compound M etal Cl - ------- white 227.27 [H2L] (9.15) 9.00 (5.93) 4.86 43 Brow n 599.94 [M n(HL)2Cl.H2O)] K (10.97 ) 10.50 ------ 60 17 5 Red p urp le 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): Electroni c spectral data, HPLC and con ductance 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* (ohm 1 .c m 2 . mole -1 ) (HPLC) Min. solvent Ratio [H2L] 278 1570 (→  * ) (n →  * ) ------- ------- 300 1514 [Mn(HL)2Cl.H2O)]K 275 551 ( 4 Eg(G)← 6 A1g) 53 2.8 DMF 1:1 340 112 500 17 [Fe(HL)2] 300 2352 ( 5 T2← 5 E) 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 S cheme (1): The synthesis route of the complexes Whe re X=Mn II and Cu II ; and Y=Ni II and Hg II Fig. (1): The suggeste d 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) S pectra of ligand Fig. (2-B):The (I.R) S pectra of the Complex [Mn (HL)2.Cl .H2O]K Fig. (2-D): The (I.R) S pectra of the Complex [Co (HL) 2.H2O] Fig. (2-F): The (I.R) S pectra of the Comple x [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) S pectra 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 (H L) 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 قسم الكیمیاء ،كلیة التربیة ابن الهیثم ،جامعة بغداد الخالصة اللیكند وذلك من مفاعلةرباعیة المنح دةالجدیالمعقدات وتشخیص تضمن البحث تحضیر 2-hy droxy -1, 2-diphy nel-ethanone oxime [H2L] االیونـات مـع)M n 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 ( k [M :الصیغة العامة يالمعقدات ذ (HL) 2.Cl. H2O] و M * (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