IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Structural and Spectroscopic Study of Novel Tetradentate Macrocyclic Ligand Type N4 and It’s Complexes with CrIII, MnII, FeII, CoII, NiII ,CuII, PdII and CdII M.J. Al-Jeboori , S.M.Lateef , A. S. Mohamme d * Department of Chemistry ,College of Education , I bn Al- Haitham Unive rsity of Baghdad *Department of Chemistry, College of Education of Women , Anbar Unive rsity Abstract Ethy lenediamine was reacted in the first st ep with 2,5 – hexandion to p roduce the p recursor [A] , then [A] was reacted with diethy lmalonate to give the new tetradentate macrocy clic Ligand [H2L].This Ligand was reacted with some metal ions in ethanol to give a series of new metal comp lexes of the general formula [M (HnL)X] m ( where : M = Cr II I , n = 0 , X= Cl2 , m= -1 ; M = M n II , Fe II , Ni II , Cu II , n = 1 , X= Cl2 , m = -1 ; M = Co II , n = 0 , X = Cl , m = -1 ; M = Pd II , n = 0 , X=0 , m = 0 ; M = Cd II , n = 2 , X = 0 , m = +2 . All comp ounds were characterized by sp ectroscop ic methods [I.R, U.V-Vis , HPLC , At omic Absorp tion] , microanaly sis of elements (C.H.N) along with conductivity measurements . From the above date the p rop osed molecular st ructure for Cr II I , M n II , Fe II , Ni II and Cu II comp lexes is octahedral, While Co II , Pd II , and Cd II form trigonal bipy ramid , square planar and tetrahedral geometries resp ectively . Introduction The macrocy clic comp ounds ty p es N4 are considered to be good coordinated ligands because they involve hard nitrogen atoms as well as the high selectivity of these compounds to extract some metal ions such as Co II , Cu II , and Ag I , [1,2] . M oreover there is a great imp ortance of tetradentate ligands ty p e N4 with variety substituents on t he molecule and their comp lexes with some transition metals , M g II and Ca II in the metallic enzy me , blood protein [3] , vitamin B12 which contains cobalt ion and in the chlorop hy ll which contains M g II [4] . Recently , comp lexes containing macrocy clic ligand ty p e N4 donor atoms p lay a very imp ortant role in the biological sy st ems such as Ca II , Fe II and Pd II comp lexes [5] and high st able comp lexes of this ty p e ligand with Tc 99m , Re 186 , Re 188 are used for radiop harmaceuticals app lications [ 6,7 ] and in magnetic resonance imaging [8] , also with Ni II which are used as cataly st for division DNA molecules [9] and Fe II comp lex with p orp hy rin as a model for biological p roteins such as hemoglobin in blood [4,10] . This p aper reports the sy nthesis and characterization of new macrocy clic ligand derived from the reaction of ethy lenediamin with 2,5-hexandion to p roduce p recursore [A] which reacted with diethy lmalonate , then the new macrocy clic ligand comp lexes with Cr II , M n II , Fe II , Co II , Ni II , Cu II , Pd II and Cd II were prepared . Experimental a- Materials and physical me asureme nt : All chemicals are from fluka and Redial-Dehenge chemical Co. Elemental microanaly sis were carried out by C.H.N analyzer ,model 1106 (Carlo-Erba) ( at t he IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 laboratories of Chemistry Dep artment, Collage of Science , Al-M ust ansiriy a University ) . M etal contents of the comp lexes were determined by shimadzu–A.A-680G At omic Absorp tion sp ectrop hotometer ( at laboratories of Ibn Ceena Co.) . IR sp ectra were recorded as KBr discs by using shimadzu 8300 FT IR sp ectrop hotometer in the range (4000-400) cm -1 (sp ectra were recorded at Collage of Science , Al-M ust ansiriy a University ). Electronic sp ectra of the p repared comp ounds were measured in the range (200-900) nm for 10 -3 M solution in DM SO at 25 o C by using shimadzu , 160 sp ectrop hotometer with 1.000± 0.001 cm matched quartz cell ( at Collage of Science Baghdad University ) . Electrical molar conductivity measurements of the comp lexes were recorded at 25 o C for 10 -3 M solution of samples in DM SO by using PW , 526digital conductivity meter. High Performance Liquid Chromatography (HPLC) was used in order to record the chromatogram of the complexes by using (HPLC) shimadzu LC-6A and column (ODS-C18) at 250 nm by using CH2Cl2 as mobile p hase and by Isocratic Elutions (ODS=Octadecy lsilance) ( at laboratories of Ibn Ceena Co.) . M elting p oints were recorded by using st urat melting p oint ap p aratus. b- S ynthesi s of Ligand [H2L] : The ligand [H2L] was prepared in two ste ps : In the first st ep, the solution of 2,5 – hexandion (1.0gm , 8.7mmole) was dissolved in (60)ml ethanol and was added slowly to a mixture of ethy lenediamine (1.05gm , 17.4 mmole) dissolved in ethanol (10ml) and (0.3ml) of (48%) HBr in (100ml) round bottom flask with st irring under inert atmosp here of N2 gas. The mixture was allowed to reflux for (4)hrs, t hen the solvent was removed under reduced p ressure , during this time, a red oily p roduct was obtained (precursore A) , y ield (1.7)gm (89%) . In the second st ep p recursor [A] (0.6gm , 3mmol) was dissolved in ethanol (40ml) in ( 100ml) round bottom flask , with Et3N (0.16ml,1.2 mmole) as a base to comp lete the reaction which is very sensitive to Et3N , then diethy lmalonate (0.48gm,3 mmole) was dissolved in (30ml) ethanol which was added to the above solution with st irring under inert atmosp here of N2 gas. The reaction mixture was allowed to reflux for (2)hrs then cooled at room temp erature and filtered and let the unreacted st arting materials and ethanol to be removed under vacuum to give a dark red oily sep arate , yield (0.74)gm , (91%) (table-1) . c-S ynthesi s of complexes : All complexes were prepared as fol lows : A mixture of [H2L] (0.072gm , 0.3mmole) in ethanol (10)ml and Et3N (0.16ml,1.2mmole) was added drop wise to (100ml) round bottom flask which contains a solution of metal chloride salt M Cln.XH2O (0.3mmole) dissolved in (5) ml ethanol, (where : M =Cr II I , M n II , Fe II , Co II , Ni II , Cu II , Pd II and Cd II ; n = 3,2,2,2,2,2,2 and 2 ; X=6 , 4,4,6,6,2,0 and 2 resp ectively . The reaction mixture was allowed to reflux for (1.5)hrs, during this time the coloury p recipitate was formed which was filtered and dried at room temp erature to give the weight of p roduct complex and yield % (table-1) . Re sults and Discussion a - The prepared precursor [A] : The p recursor [A] was p repared by using a high dilution method which contains the reaction of 2,5-hexandion with ethy lenediamine in ethanol solvent according to the general method shown in scheme-1. The p recursor [A] was dissolved in H2O,DM SO,CH3OH and C2H5OH . Some p hy sical prop erties and microanalysis C.H.N for [A] were listed in table-1 and table-2. The I.R sp ectrum for [A] (Fig.1) disp lay ed two bands at (3450)cm -1 and (3354) cm -1 due to υasy .(N-H) and υsy .(N-H) resp ectively [11] , the band at (1630) cm -1 is assigned to υ(C=N) for the imine group [12] with the disap p earance of absorp tion band at (1750) cm -1 IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 which was att ributed to st retching frequency of ketonic carbony l group υ(C=0) for 2,5- hexandion , other bands of [A] were listed in table-3 . b - The prepared Ligand [H2L] The p ro-ligand [H2L] was p repared by the reaction of p recursor [A] with diethy lmalonate by using Et3N in ethanol solvent according to the general method shown in scheme -1 . The ligand [H2L] was dissolved in DM SO , DM F , CH3OH and C2H5OH , some phy sical prop erties and microanalysis C.H.N for [H2L] were list ed in table -2 . The I.R sp ectrum for [H2L] (Fig.2) disp lay ed two bands at (3382)cm -1 and (3286) cm - 1 is due to t he υasy .(N-H) and υsy .(N-H) st retching frequency resp ectively [13] , the band at (1652) cm -1 due to st retching frequency of amidic carbony l group υ(C=0) [14], also I.R sp ectrum disp lay ed absorp tion band at (1600) cm -1 due to υ(C=N) [12,15] which was shifted to alower frequency when it comp ared with υ(C=N) at (1630) cm -1 in I.R sp ectrum for [A] . In addition to these bands ,a new double band at (1022) cm -1 and (979) cm -1 was observed which was due to the formation of macrocy cle [16,17] , other bands of [H2L] were listed in table-3 . The u.v-vis sp ectrum for [H2L] (Fig.6) exhibits a high intense absorp tion p eak at 208nm ( 48077cm -1 , εmax = 2200m -1 , cm -1 ) due to ( π π * ) electronic transition while the two absorp tion peaks at 294nm ( 34013 cm -1 , εmax = 281 m -1 .cm -1 ) and 338nm (29585 cm -1 , εmax = 274m -1 .cm -1 ) are att ributed to (n π * ) electronic transition for (n) electrons of O and N atoms in [H2L] [18]. c - The prepared complexes Reaction of [H2L] with metal chloride salt M Cln.XH2O (exp erimental Part-C) was carried out in ethanol under reflux in the p resence of Et3N which was used in order to remove the hy drogen from two amidic group s (NH). All comp lexes are st able in solution and electrolytes (table-4) , the analytical and p hy sical data (table-1,table-2) and sp ectral data (table-3, table-4) are comp atible with the suggested st ructures (Fig.10). All comp lexes dissolve in methanol and DM SO solvents . Molar Conductance The molar conductance of the comp lexes in DM SO solvent in 10 -3 M at 298 o K (table-2) indicated electrolytic nature with(1:1) ratio for [Et3NH][Cr(L)Cl2] , [Et3NH][M n(HL)Cl2] , [Et3NH][Fe(HL)Cl2] , [Et3NH][Co(L)Cl] , [Et3NH][Ni(HL)Cl2] , [Et3NH][Cu(HL)Cl2] comp lexes and (2:1) ratio for [Cd(H2L)]Cl2 comp lex while the molar conductance value for [Pd(L)] comp lex indicate neutral nature [19,20] . I.R spectra The I.R sp ectra for all complexes (table-3) gave different sp ectra in comp arison with t hat of free ligand [H2L] . 1- In general, the I.R sp ectra for all comp lexes exhibit a shift in st retching frequency of amidic carbony l group υ (C=O) when comp ared with that of free ligand[H2L] at (1652) cm -1 , in addition to overlap a band of υ(C=O) in all comp lexes with a band of υ(C=N) at range (1614-I633)cm -1 . This shifting can be related to the delocalization of metal ion electronic density in π -Orbital of the ligand and formation of π -back bonding (dπ-Pπ) which indicates the coordination between N atoms of C=N group s of t he ligand [H2L] and metal ion [21,22]. 2- The I.R sp ectra of M n II , Fe II , Ni II (Fig.3) , Cu II and Cd II (Fig.4) comp lexes revealed a broad band at range (3413-3460) cm -1 due to t he overlap of υasy . (N-H) and υsy .(N-H) which were shifted to a higher frequency when comp ared with that of free ligand at (3382) cm -1 , also δ(N-H) was shifted to a lower frequency and app eared at range (1512-1525)cm -1 , while the bands of υ(N-H) and δ (N-H) disapp eared in I.R sp ectra of Cr II I (Fig.5),Co II and Pd II comp lexes , this indicates two p rotons of (N-H) group s in [H2L] which were removed and anionic ligand (-2) was formed in Cr II I , Co II and Pd II comp lexes only. The shifting of υ(N-H) IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 and δ(N-H) in I.R sp ectra of some comp lexes and disapp earance of it in other comp lexes refer to the coordination between N atom of amidic group and metal ion [23] . 3- The band of υ(C-N) at range (1157-1172) cm -1 in I.R sp ectra of all comp lexes was shifted to a higher frequency in comparison with t hat of free ligand [H2L] at (1147)cm -1 . 4- New bands app eared at range (440-536) cm -1 in I.R sp ectra of all complexes which haven’t been p resent in the ligand sp ectrum , this may be attributed to υ(M -N) [24,25] . 5- The I.R sp ectra of Cr II I , M n II , Fe II , Co II , Ni II , and Cu II comp lexes exhibit three bands at (2744,2677,2489) cm -1 assigned to the vibration frequencies of ammonium group [Et3NH] + [26]. Electroni c spectra 1- The electronic sp ectral data of all comp lexes are summarized in (table–4) . The two p eaks (208) nm and (338) nm in the electronic sp ectrum of [H2L] were shifted to a higher frequency but the p eak at (294)nm was shifted to a lower frequency and these three p eaks ap p eared in the electronic sp ectra of all comp lexes at range (236-258) nm , (267-280) nm and (342- 358)nm , these shiftings in ligand field p eaks indicate coordination[H2L]with metal ion [18] . 2- New absorp tion p eaks app eared at (479)nm and (454) nm in the electronic sp ectra of Fe II , Cu II comp lexes resp ectively att ributed to charge transfer electronic transition (M L) [27]. 3- The electronic sp ectra of Cr II I , M n II , Fe II (Fig.7) , Ni II and Cu II comp lexes disp lay ed new absorp tion peaks assigned to (d-d) electronic transitions as follows : Cr II I comp lex 806 nm ( 4 A2g 4 T2g) ; M n II comp lex 442nm ( 6 A1g 4 Eg(G) , 4 A1g(G)) ,494nm ( 6 A1g 4 T2g(G) ) , 538nm , ( 4 A1g 4 T1g(G)) ; Fe II comp lex 888nm ( 5 T2g 5 Eg) , Ni II comp lex 622nm( 3 A2g 3 T1g ) and Cu II comp lex 800 nm ( 2 Eg 2 T2g) , in fact t hese results are in a good agreement with the p revious works of Cr II I , M n II , Fe II , Ni II and Cu II comp lexes of octahedral geometry [28-32) . 4- New p eak app eared in the u.v-vis sp ectrum of Co II comp lex (Fig.8) at (756)nm was assigned to (d-d) electronic transition ty p e ( 4 À2(F) 4 E ̀(F) ) suggesting a trigonal bipy ramidal geometry about Co II [33]. 5- While the u.v-vis sp ectrum of Pd II comp lex shows a new absorp tion peak at (454)nmwhich was assigned to (d-d) electronic transition ty p e ( 1 A1g 1 B1g) which is a good evidence for a square p laner geometry about Pd II [31,32]. 6- Finally , the u.v-vis sp ectrum of Cd II comp lex shows no absorp tion p eak at range (370- 1100) nm , that indicates no (d-d) electronic transition happ ened (d 10 -sy st em) in visible region , that is a good result for Cd II tetrahedral complexes [34]. Atomic Absorption The atomic absorp tion measurements (table-2) for all comp lexes gave app roximated values for their theoretical. High Performance Liqui d Chromatography The HPLC chromatograms for Cr II I , M n II , Fe II (Fig.9a) and Co II (Fig.9b) comp lexes exhibited interfering signal at tR(3.29 , 3.73)min, (2.56 , 2.94) min (3.54,3.89)min and (2.30,2.42)min resp ectively , indicating two isomers (Cis,trans) for Cr II I , M n II , Fe II comp lexes and (trigonal bipy ramidal , square p y ramidal) for Co II comp lex. While the chromatograms for Ni II (Fig.9c) and Cu II (Fig.9d) comp lexes show one signal at tR(2.91)min and (3.75)min resp ectively indicating the purity of the complexes. Conclusion Our invest igation suggests that the ligand [H2L] behaves as tetradentate on complexation with metal ions forming octahedral geometry about Cr II I , M n II , Fe II , Ni II and Cu II trigonal IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 bipy ramidal geometry about Co II , square p lanar coordinated about Pd II , and finally tetrahedral geometry about Cd II . Re ferences 1- Zolotov,Y,A.(1979),“M acrocyclic comp ounds in Analytical Chemistry ” New York , 2 nd , 82 . 2- Handel, I.L.; M uller,R.and Gnglielmeti,R. (1983),Inorg.Chimi.Acta 66 :514. 3- Brown ,D.G. (1973), Prog.Inorg.Chem. , 13:177 . 4- Warren, M .J. and Shah , H.N. (2000), Biolog.Chem , 275:316 . 5- Kimura , E. ; Koike , T.; Watanabe, T. ;Aoki , S. and Shiro, M . (1996), J. Am . Chem. Soc. , 118 :2696 . 6- Franz , J. ;Volkert, W.A. ;Barefield , E.K. and Holmes , R.A. (1987), Nucl. M ed. Biol. ; 14: 569 ,. 7- Jurisson , S. ;Bering, D. and Dongshema (1993), Inorg.Chem.-Rev.; 93 : 1137,. 8- Long , K.M . and Busch , D.H. (1970), Inorg. Chem, 9 :505 . 9- Brown , K.L. and Evans , D.R. (1990),Inorg. Chem. ; 29:2559 ,. 10- Tenhunen , R. ;M arver , H.S. and schmid , R. (1968), Proc. Nacl. Acad. Sci. U.S.A. , 61 :748 11- Socrates , G. (1980),“ Infrared Characteristic Group Frequencies“ John willy and sons , Ltd , New York . 12- Hadzi , D. (1956), J. Chem. Soc , 2725 . 13- Fabiametal , J. (1956),Bull. Soc. Chim. France , 1499. 14- Bear , M . (1958), J. Chem. Phy s. , 29 , 1097 . 15- M argerum , J.D. and Sousa , J.A. (1965),Ap p . Sp ectro. , 19 :91. 16- Jakels , S.C. ; Clavola , J. ;Carter , R.C. ; Cheek , P.L. and Pascarelli, T.D. (1983),Inorg. Chem. , 22:3956 . 17- Shakir,M .; M ohamed,A.K.; Varkey , S.P.and Nasman,O.S.M . (1996), Indian J.Chem., 35:935 18- Al-M ukhtar, S.E. and M ust afa, L.H.A. (1988) ‘’ Inorganic and coordination Chemistry ‘’ . M osul university ,Iraq,1 st ,612 . 19- Kettle, S.F.A. (1975) “ Coordination comp ounds “. Thomas Nelson and sons , London, 165. 20- Quaglian,J.V.; Fuseta, J. and Franz,G. (1961),J.Am.Chem.Soc ,81:377. 21- Hadzi, D. and Premru, L. (1967), sp ectrochim.Acta., 23A:35 . 22- Agrawal,R.K.; Prasad,S. and Gahlot, N. (2004),T wK. J.Chem., 28 . 23- M arcotrigano , G. and Pellaccani , G.C. (1975),Z .Anorg. Allg. Chem. , 415:168-274 24- Prehadaran , G.P. and Patelc, C.J. (1969),J.Inorg. Nucl. Chem., 13:3316. 25- Nakamato,K. (1977), “ Infrared and Raman Sp ectra of Inorganic and coordination comp ounds “ . John Wiley and sons , Inc. New York . 26- Rouschrian, Q. and Wilkinson , G. (1968), J.Chem . Soc, 489. 27- Lever , A.B.P. (1963), J. Chem. Soc. , 2552. 28- Jorgensen , C.K. (1963), Advan. Chem . Phy s. , 5:33. 29- Heidt, L.F. ; Koster , B.F. and Johnson , A.M . (1958), J.Am, Chem. Soc. , 80:6471 30- M adeia , K. and Konig,E. (1964), J. Inorg. Nucl. Chem., 25 :2408 . 31- Lever, A.B.P. (1968), “ Inorganic Electronic Sp ectroscop y “, Elsevier Publishing comp any , New York . 32- Holmes , O. G. and M cclure , D.S. (1957), J. Chem. Phy s.,26:1686. 33- Dance, L.G.; Gerloch,M .; Lewis,J.; Stephens ,F.S. and Liorrs, F. (1966), Nature 210:289. 34- Bonati,F. and Vgo,R. (1967), J. Organometal. Chem.,10: 257-268. IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 S cheme –1 : Preparation method for precursor [ A] and li gand [H2L] Fig. (1): I.R. S pectrum of the precursor [A] . IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.(2): I.R. S pectrum of the Ligand [H2L] . Fig. (3): I.R. S pectrum of the complex [Et3NH][Ni (HL)Cl 2] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.( 4): I.R. S pectrum of the complex [Cd(H2L)] Cl 2 Fig. (5): I.R. S pectrum of the complex [Et3NH][Cr(L)Cl 2] Fig. (6): Electroni c S pectrum of the Ligand[H2L] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig. (7): Electroni c S pectrum of the Complex [Et3NH][Fe(HL)Cl 2] Fig. (8): Electroni c S pectrum of the Complex [Et3NH][Co(L)Cl ] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.(9): Chromatogram of the complexes : a. [Et3NH][Fe(H L)Cl 2] . b. [ Et3NH][Co(L)Cl ] c. [Et3NH][Ni (HL)Cl 2] . d. [Et3NH][Cu(HL)Cl 2] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 a b c d Fig.( 10) :The Suggested S tructures for the Prepared Complexes . (22مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة المجلد 4 (2009 ومعقداته مع N4نوع د دراسة تركیبیة وطیفیة للیكاند رباعي السن الجدی CrIII, MnII, FeII, CoII, NiII ,CuII, PdII ، CdII محمد جابر الجبوري ، ساجد محمود لطیف ، عید صالح محمد * جامعة بغداد ، ابن الهیثم – كلیة التربیة ،قسم الكیمیاء جامعة األنبار ، كلیة التربیة للبنات، قسم الكیمیاء* الخالصة بخطــوتین ، فـي الخطــوة األولـى تــم مفاعلـة األثیلــین ثنــائي N4نــوع ] H2L[حـضر اللیكانــد ربـاعي الــسن الجدیـد مـع ثنـائي أثیـل ،]A[بینمـا تـضمنت الخطـوة الثانیـة مفاعلـة المـشتق ] A[ هكسان دایون إلنتاج المشتق – 5 ، 2األمین مع . مالونیت M]الفلزیة ذا الصیغة العامة ] H2L[حضرت سلسلة من معقدات اللیكاند (HnL)X] m : تمثل اذ M = Cr II I , n = 0 , X= Cl2 , m= -1 ; M = M n II , Fe II , Ni II , Cu II , n = 1 , X= Cl2 , m = -1 ; M = Co II , n = 0 , X = Cl , m = -1 ; M = Pd II , n = 0 , X=0 , m = 0 ; M = Cd II , n = 2 , X = 0 , m = +2 ـــراء ، المرئیــــة ( شخـــصت جمیــــع المركبــــات المحــــضرة بــــالطرائق الطیفیــــة فــــوق البنفــــسجیة ، –األشــــعة تحــــت الحمـ ـــل الكمـــي الــــدقیق للعناصـــر والتوصــــیلیة ) األداء العــــالي واالمتـــصاص الــــذريو كروموتوكرافیـــا الـــسائل ذ ًفـــضال عـــن التحلیـ ــــة ــــ ــــات. الموالریـــ ــــ ـــــذه التقنیــــ ــــ ــــــات هــ ــــ ـــن معطیـ ــــ ــــداتومــــ ــــ ــــسطوح لمعقــــ ــــ ـــــاني الـــ ــــ ـــــــشكل ثمــ ـــرح الــــ ــــ Cr اقتــــ II I ،M n II ،Cu II , Ni II , Fe II Co والشكل ثنائي الهرم المثلثـي لمعقـد ، II Cdوالـشكل ربـاعي الـسطوح لمعقـد II واتخـذ معقـد ، Pd II . هیأة المربع المستوي