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. Mohammed * Department of Chemistry ,College of Education , Ibn Al- Haitham University of Baghdad *Department of Chemistry, College of Education of Women , Anbar University Abstract Ethylenediamine was reacted in the first step with 2,5 – hexandion to produce the precursor [A] , then [A] was reacted with diethylmalonate to give the new tetradentate macrocyclic Ligand [H2L].This Ligand was reacted with some metal ions in ethanol to give a series of new metal complexes of the general formula [M(HnL)X]m ( where : M= CrIII , 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 = CdII , n = 2 , X = 0 , m = +2 . All compounds were characterized by spectroscopic methods [I.R, U.V-Vis , HPLC , Atomic Absorption] , microanalysis of elements (C.H.N) along with conductivity measurements . From the above date the proposed molecular structure for CrIII , MnII , FeII , Ni II and Cu II complexes is octahedral, While Co II , Pd II , and Cd II form trigonal bipyramid , square planar and tetrahedral geometries respectively . Introduction The macrocyclic compounds types 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] . Moreover there is a great importance of tetradentate ligands type N4 with variety substituents on the molecule and their complexes with some transition metals , Mg II and CaII in the metallic enzyme , blood protein [3] , vitamin B12 which contains cobalt ion and in the chlorophyll which contains M g II [4] . Recently, complexes containing macrocyclic ligand type N4 donor atoms play a very important role in the biological systems such as Ca II , Fe II and Pd II complexes [5] and high stable complexes of this type ligand with Tc 99m , Re186 , Re188 are used for radiopharmaceuticals applications [ 6,7 ] and in magnetic resonance imaging [8] , also with Ni II which are used as catalyst for division DNA molecules [9] and Fe II complex with porphyrin as a model for biological proteins such as hemoglobin in blood [4,10] . This paper reports the synthesis and characterization of new macrocyclic ligand derived from the reaction of ethy lenediamin with 2,5-hexandion to produce precursore [A] which reacted with diethylmalonate , then the new macrocyclic ligand complexes with Cr II , MnII , Fe II , Co II , Ni II , Cu II , Pd II and Cd II were prepared . Experimental a- Materials and physical measurement : All chemicals are from fluka and Redial-Dehenge chemical Co. Elemental microanalysis were carried out by C.H.N analyzer ,model 1106 (Carlo-Erba) ( at the IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 laboratories of Chemistry Department, Collage of Science , Al-Mustansiriya University ) . Metal contents of the complexes were determined by shimadzu–A.A-680G Atomic Absorption spectrophotometer ( at laboratories of Ibn Ceena Co.) . IR spectra were recorded as KBr discs by using shimadzu 8300 FTIR spectrophotometer in the range (4000-400) cm -1 (spectra were recorded at Collage of Science , Al-Mustansiriya University ). Electronic spectra of the prepared compounds were measured in the range (200-900) nm for 10 -3 M solution in DM SO at 25oC by using shimadzu , 160 spectrophotometer with 1.000± 0.001 cm matched quartz cell ( at Collage of Science Baghdad University ) . Electrical molar conductivity measurements of the complexes 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 phase and by Isocratic Elutions (ODS=Octadecylsilance) ( at laboratories of Ibn Ceena Co.) . Melting points were recorded by using sturat melting point apparatus. b- Synthesis of Ligand [H2L] : The ligand [H2L] was prepared in two steps : In the first step, 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 stirring under inert atmosphere of N2 gas. The mixture was allowed to reflux for (4)hrs, then the solvent was removed under reduced pressure , during this time, a red oily product was obtained (precursore A) , y ield (1.7)gm (89%) . In the second step precursor [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 complete the reaction which is very sensitive to Et3N , then diethylmalonate (0.48gm,3 mmole) was dissolved in (30ml) ethanol which was added to the above solution with stirring under inert atmosphere of N2 gas. The reaction mixture was allowed to reflux for (2)hrs then cooled at room temperature and filtered and let the unreacted starting materials and ethanol to be removed under vacuum to give a dark red oily separate , yield (0.74)gm , (91%) (table-1) . c-Synthesis of complexes : All complexes were prepared as follows : 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 MCln.XH2O (0.3mmole) dissolved in (5) ml ethanol, (where : M=Cr III, MnII, FeII, CoII, NiII, CuII, PdII and CdII ; n = 3,2,2,2,2,2,2 and 2 ; X=6 , 4,4,6,6,2,0 and 2 respectively . The reaction mixture was allowed to reflux for (1.5)hrs, during this time the coloury precipitate was formed which was filtered and dried at room temperature to give the weight of product complex and yield % (table-1) . Results and Discussion a - The prepared precursor [A] : The precursor [A] was prepared 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 precursor [A] was dissolved in H2O,DM SO,CH3OH and C2H5OH . Some physical properties and microanalysis C.H.N for [A] were listed in table-1 and table-2. The I.R spectrum for [A] (Fig.1) displayed two bands at (3450)cm -1 and (3354) cm-1 due to υasy.(N-H) and υsy .(N-H) respectively [11] , the band at (1630) cm-1 is assigned to υ(C=N) for the imine group [12] with the disappearance 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 attributed to stretching frequency of ketonic carbonyl group υ(C=0) for 2,5- hexandion , other bands of [A] were listed in table-3 . b - The prepared Ligand [H2L] The pro-ligand [H2L] was prepared by the reaction of precursor [A] with diethylmalonate 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 physical properties and microanalysis C.H.N for [H2L] were listed in table -2 . The I.R spectrum for [H2L] (Fig.2) displayed two bands at (3382)cm -1 and (3286) cm - 1 is due to the υasy .(N-H) and υsy.(N-H) stretching frequency respectively [13] , the band at (1652) cm-1 due to stretching frequency of amidic carbonyl group υ(C=0) [14], also I.R spectrum displayed absorption band at (1600) cm-1 due to υ(C=N) [12,15] which was shifted to alower frequency when it compared with υ(C=N) at (1630) cm-1 in I.R spectrum 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 macrocycle [16,17] , other bands of [H2L] were listed in table-3 . The u.v-vis spectrum for [H2L] (Fig.6) exhibits a high intense absorption peak 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 attributed 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 MCln.XH2O (experimental Part-C) was carried out in ethanol under reflux in the presence of Et3N which was used in order to remove the hydrogen from two amidic groups (NH). All complexes are stable in solution and electrolytes (table-4) , the analytical and physical data (table-1,table-2) and spectral data (table-3, table-4) are compatible with the suggested structures (Fig.10). All complexes dissolve in methanol and DMSO solvents . Molar Conductance The molar conductance of the complexes in DM SO solvent in 10 -3M at 298oK (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] complexes and (2:1) ratio for [Cd(H2L)]Cl2 complex while the molar conductance value for [Pd(L)] complex indicate neutral nature [19,20] . I.R spectra The I.R spectra for all complexes (table-3) gave different spectra in comparison with that of free ligand [H2L] . 1- In general, the I.R spectra for all complexes exhibit a shift in stretching frequency of amidic carbonyl group υ (C=O) when compared with that of free ligand[H2L] at (1652) cm -1 , in addition to overlap a band of υ(C=O) in all complexes 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 groups of the ligand [H2L] and metal ion [21,22]. 2- The I.R spectra of Mn II , FeII , NiII (Fig.3) , CuII and CdII (Fig.4) complexes revealed a broad band at range (3413-3460) cm-1 due to the overlap of υasy. (N-H) and υsy.(N-H) which were shifted to a higher frequency when compared with that of free ligand at (3382) cm-1 , also δ(N-H) was shifted to a lower frequency and appeared at range (1512-1525)cm -1 , while the bands of υ(N-H) and δ (N-H) disappeared in I.R spectra of Cr III (Fig.5),CoII and PdII complexes , this indicates two protons of (N-H) groups in [H2L] which were removed and anionic ligand (-2) was formed in CrIII , CoII and PdII complexes 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 spectra of some complexes and disappearance of it in other complexes 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 spectra of all complexes was shifted to a higher frequency in comparison with that of free ligand [H2L] at (1147)cm -1 . 4- New bands appeared at range (440-536) cm -1 in I.R spectra of all complexes which haven’t been present in the ligand spectrum , this may be attributed to υ(M-N) [24,25] . 5- The I.R spectra of CrIII , MnII , FeII , CoII , NiII , and CuII complexes exhibit three bands at (2744,2677,2489) cm-1 assigned to the vibration frequencies of ammonium group [Et3NH]+ [26]. Electronic spectra 1- The electronic spectral data of all complexes are summarized in (table–4) . The two peaks (208) nm and (338) nm in the electronic spectrum of [H2L] were shifted to a higher frequency but the peak at (294)nm was shifted to a lower frequency and these three peaks appeared in the electronic spectra of all complexes at range (236-258) nm , (267-280) nm and (342- 358)nm , these shiftings in ligand field peaks indicate coordination[H2L]with metal ion [18] . 2- New absorption peaks appeared at (479)nm and (454) nm in the electronic spectra of Fe II, CuII complexes respectively attributed to charge transfer electronic transition (M L) [27]. 3- The electronic spectra of Cr III, MnII, FeII (Fig.7) , NiII and CuII complexes displayed new absorption peaks assigned to (d-d) electronic transitions as follows : CrIII complex 806 nm (4A2g 4T2g) ; MnII complex 442nm (6A1g 4Eg(G) , 4A1g(G)) ,494nm (6A1g 4T2g(G) ) , 538nm , ( 4 A1g 4 T1g(G)) ; Fe II complex 888nm ( 5 T2g 5 Eg) , Ni II complex 622nm( 3A2g 3T1g ) and CuII complex 800 nm (2Eg 2T2g) , in fact these results are in a good agreement with the previous works of CrIII, MnII, FeII, NiII and CuII complexes of octahedral geometry [28-32) . 4- New peak appeared in the u.v-vis spectrum of CoII complex (Fig.8) at (756)nm was assigned to (d-d) electronic transition type ( 4 À2(F) 4 E ̀(F) ) suggesting a trigonal bipyramidal geometry about Co II[33]. 5- While the u.v-vis spectrum of PdII complex shows a new absorption peak at (454)nmwhich was assigned to (d-d) electronic transition type (1A1g 1B1g) which is a good evidence for a square planer geometry about PdII [31,32]. 6- Finally , the u.v-vis spectrum of Cd II complex shows no absorption peak at range (370- 1100) nm , that indicates no (d-d) electronic transition happened (d 10-system) in visible region , that is a good result for CdII tetrahedral complexes [34]. Atomic Absorption The atomic absorption measurements (table-2) for all complexes gave approximated values for their theoretical. High Performance Liquid Chromatography The HPLC chromatograms for Cr III , MnII , FeII (Fig.9a) and CoII (Fig.9b) complexes 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 respectively , indicating two isomers (Cis,trans) for Cr III , Mn II , Fe II complexes and (trigonal bipyramidal , square pyramidal) for Co II complex. While the chromatograms for NiII(Fig.9c) and CuII(Fig.9d) complexes show one signal at tR(2.91)min and (3.75)min respectively indicating the purity of the complexes. Conclusion Our investigation suggests that the ligand [H2L] behaves as tetradentate on complexation with metal ions forming octahedral geometry about Cr III, MnII, FeII, NiII and CuII trigonal IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 bipyramidal geometry about Co II, square planar coordinated about PdII, and finally tetrahedral geometry about CdII . References 1- Zolotov,Y,A.(1979),“Macrocyclic compounds in Analytical Chemistry” New York , 2nd , 82 . 2- Handel, I.L.; Muller,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. Med. 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. ;Marver , 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. Phys. , 29 , 1097 . 15- Margerum , J.D. and Sousa , J.A. (1965),App. Spectro. , 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.; Mohamed,A.K.; Varkey, S.P.and Nasman,O.S.M. (1996), Indian J.Chem., 35:935 18- Al-Mukhtar, S.E. and Mustafa, L.H.A. (1988) ‘’ Inorganic and coordination Chemistry ‘’ . Mosul university,Iraq,1 st ,612 . 19- Kettle, S.F.A. (1975) “ Coordination compounds “. 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), spectrochim.Acta., 23A:35 . 22- Agrawal,R.K.; Prasad,S. and Gahlot, N. (2004),TwK. J.Chem., 28 . 23- Marcotrigano , 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 Spectra of Inorganic and coordination compounds “. 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 . Phys. , 5:33. 29- Heidt, L.F. ; Koster , B.F. and Johnson , A.M. (1958), J.Am, Chem. Soc. , 80:6471 30- Madeia , K. and Konig,E. (1964), J. Inorg. Nucl. Chem., 25 :2408 . 31- Lever, A.B.P. (1968), “ Inorganic Electronic Spectroscopy “, Elsevier Publishing company , New York . 32- Holmes , O. G. and Mcclure , D.S. (1957), J. Chem. Phys.,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 Scheme –1 : Preparation method for precursor [A] and ligand [H2L] Fig. (1): I.R. Spectrum of the precursor [A] . IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.(2): I.R. Spectrum of the Ligand [H2L] . Fig. (3): I.R. Spectrum of the complex [Et3NH][Ni(HL)Cl2] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig.( 4): I.R. Spectrum of the complex [Cd(H2L)] Cl2 Fig. (5): I.R. Spectrum of the complex [Et3NH][Cr(L)Cl2] Fig. (6): Electronic Spectrum of the Ligand[H2L] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 Fig. (7): Electronic Spectrum of the Complex [Et3NH][Fe(HL)Cl2] Fig. (8): Electronic Spectrum 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(HL)Cl2] . b. [Et3NH][Co(L)Cl] c. [Et3NH][Ni(HL)Cl2] . d. [Et3NH][Cu(HL)Cl2] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L.22 (4) 2009 a b c d Fig.( 10) :The Suggested Structures for the Prepared Complexes . 2009) 4 (22مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة المجلد 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 ـائي N4نــوع ] H2L[حـضر اللیكانــد ربـاعي الــسن الجدیـد بخطــوتین ، فـي الخطــوة األولـى تــم مفاعلـة األثیلــین ثنـ مـع ثنـائي أثیـل ،]A[بینمـا تـضمنت الخطـوة الثانیـة مفاعلـة المـشتق ] A[ هكسان دایون إلنتاج المشتق – 5 ، 2األمین مع . مالونیت [M(HnL)X]الفلزیة ذا الصیغة العامة ] H2L[حضرت سلسلة من معقدات اللیكاند m تمثل اذ : M= Cr III , n = 0 , X= Cl2 , m= -1 ; M= M n II , Fe II , Ni II , Cu II , n = 1 , X= Cl2 , m = -1 ; M = CoII , n = 0 , X = Cl , m = -1 ; M = PdII , n = 0 , X=0 , m = 0 ; M = CdII , n = 2 , X = 0 , m = +2 ـات المحــــضرة بــــالطرائق الطیفیــــة ـــراء ، المرئیــــة ( شخـــصت جمیــــع المركبـــ فــــوق البنفــــسجیة ، –األشــــعة تحــــت الحمـ ـــذريو كروموتوكرافیـــا الـــسائل ذ ــالي واالمتـــصاص الـ ــــدقیق للعناصـــر والتوصــــیلیة ) األداء العــ ـــل الكمـــي ال ًفـــضال عـــن التحلیـ ــــة ــــ ــــات. الموالریـــ ــــ ــــ ـــــذه التقنی ــــ ــات هــ ــــ ــــ ـــن معطیـ ــــ ــــداتومــــ ــــ ــــسطوح لمعقــــ ــــ ـاني الـــ ــــ ــــ ـــشكل ثمــ ــــ ــــ ـــرح ال ــــ ــــ Cr اقت III ،Mn II ،CuII , NiII, FeII ، والشكل ثنائي الهرم المثلثـي لمعقـد CoII والـشكل ربـاعي الـسطوح لمعقـدCdII ، واتخـذ معقـد PdIIهیأة المربع المستوي .