IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Synthesis and Characterisation of a Novel 2,3-O-di Acetyl- 5,6-O-Benzylidene - L -Ascorbic Acid and its Complexes of Cr(III), Co(II), Ni(II),Cu(II) and Zn(II) I. Sh. Abdul Razzaq Al - Kadi Department of Chemistry, College of Education, Ibn Al-Haitham, University of Baghdad Received in : 11 May 2011 Accepeted in : 20 September 2011 Abstract A new ligand type (O2) [2,3-O-diacety l-5,6-O-benzylidene L- ascorbic acid] [L] and its complexes of general formula [M(L)2(X)(Y)]Cln (where: M=Cr III ,X=Y=H2O, n=3; Co II , X = Y = 0, n= 2; Ni II and Cu II , X = Cl, Y = H2O, n= 1; Zn II , X = Y = H2O,n = 2) are reported. The ligand was prepared in two steps; first step involved the synthesis of [5,6-O-benzylidene-L-ascorbic acid] (A). In second step derivative-A was then reacted with acety l chloride and anhydrous pyridine as a base to give the titled ligand. Metal complexes of the ligand with CrIII ,Co II ,Ni II ,Cu II and ZnII were synthesised by direct reaction of the corresponding metal chloride with the ligand[L] in a 2L:1M mole ratio. The ligand and its complexes were characterised by spectroscopic methods 1 H NM R, FTIR, (UV-Vis), atomic absorption, microanalyses, chloride content, melting point and conductance measurements . These studies revealed that the geometry about CrIII, NiII,CuII and ZnII is octahedral while the complex of CoII adopts a tetrahedral geometry . Keywords: Ester, Benzylidene, L-Ascorbic acid, Metal Ascorbate Complexes, Anticancer effect. Introduction Vitamin C is the L-enantiomer of ascorbic acid (meaning “without scurvy”, the disease caused by a vitamin C deficiency)[1]. The effect of ascorbic acid (AA) on cancer has been a subject of great controversy [2]. The derivatives of L-ascorbic acid (AA) (5,6-O-Cyclic acetal) possess pharmaceutical activity similar to L- ascorbic acid, superior in crystallinty, stability, and antioxidant effect [3,4]. These derivatives have been shown to exert anticancer effect [5-7], they are free radical scavengers, and have anti-scorbutic activities [8], and reduce the arterial blood IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 pressure and regulates heart rate [9,10]. Sodium 5,6-O-benzylidene-L-ascorbate(SBA) is a conjugate of ascorbic acid with benzaldehyde. It has been found that the antioxidant activity of (SBA) is more stable and has a longer lifetime in living cells and organs than (AA) [11,12,13]. In addition it has been shown to exert anticancer effect in patients without causing side effects [6]. The PKa value of (AA) and 5,6-O-benzylidene L-ascorbic acid was exceedingly decreased by esterification of 2-OH and 3-OH slightly by that of the 5-OH and 6-OH in L-ascorbic acid [14]. The (AA) esters in 2, 3, 6 positions are more stable than (AA). The introduction of the ester in 2, 3-positions protected the molecule from break-up of the enediol system, these esters as a very stable derivatives of (AA) that may be easily used in various types of cosmetics products and drugs[15,16]. The interaction of (AA) with metal ions play an important role in the reversible oxidation of (AA) in living cells [17]. (AA) has several donor atoms capable of metal complex formation, and complexes of metal ascorbate are generally assumed to be a chelate in the crystalline solid, but chelate formation was suggested to be weak in aqueous solution [18]. The preparation of stable metal-ascorbate complexes is of considerable importance not only for their chemical but also biological and medical aspects [19]. In view of these observations, this paper deals with the synthesis and characterisation of a new ligand derived from vitamin C [2,3-O-di acety l-5,6-O-benzylidene-L-ascorbic acid] and its metal complexes with CrIII, CoII, NiII, CuII and ZnII ions. Experimental Reagents were purchased from Fluka and Riedal–Dehaën Chemical Co. The Thin Layer Chromatography (TLC) was performed on aluminum plates coated with (0.25mm) layer of silica gel F254 (Fluka), the spot was detected by iodine vapor. IR spectra were recorded as (KBr) discs using a Shimadzu 8400S FTIR spectrophotometer in the range (4000– 400) cm-1. Electronic spectra of the prepared compounds was measured in the region (200– 1100) nm for (10-3 M) solution in (DM F) at 25C by using a Shimadzu 160 spectrophotometer with 1.000+0.001cm matched quartz cell. 1 H NMR spectrum was acquired in DMSO solution using Brucker 300 MHz spectrometer at Al-al-Bayt University , Jordan. The (C.H.N.) of the ligand [L] was recorded using (EURO EA, Elemental Analysis) at College of Science – University of Babylon. Metal contents of the complexes were determined by atomic absorption (A.A) technique by using a Shimadzu A.A 680G atomic absorption spectrophotometer. The Chloride contents for complexes were determined using potentiometric titration method on 686–Titro processor Dosimat–M etrahm– Swiss. Electrical conductivity measurements of the complexes were recorded at 25C for (10-3 M) solutions of the samples in (DM F) by using a PW 9526 digital conductivity meter. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Synthesis The ligand was prepared in two steps: Step (1): preparation of the derivative (A) 5,6-O-Benzylidene-L-Ascorbic acid Anhydrous Zinc chloride (3.86 g, 28.32 mmol) was added to a solution of benzaldehyde (15 mL, 174.56 mmol ). The mixture was allowed to stir for one hour at room temperature, and then L-ascorbic acid (5.00 g, 28.38 mmol) was added and the reaction mixture was stirred overnight at room temperature until the solution became emulsion. A solution of potassium carbonate (7.84 g, 56.72 mmol) was added to the emulsion solution and the mixture was stirred through it became- milky, and then extracted with chloroform (50 mL). After solvent was removed under reduced pressure, and a syrup residue was left which then treated with a few drops of petroleum ether to give the title derivative-A as a pale yellow solid. Yield (2.93 g, 39 %). Rf = 0.69, m.p = 163C. Step (2): preparation of the ligand [L] 2,3-O-di Acety l-5,6-O-Benzylidene L-Ascorbic acid To a mixture of compound-A (5.00 g, 18.93 mmol) in a dried pyridine (25 mL) was added acety l chloride (4 mL, 56.81 mmol). The reaction mixture was stirred at room temperature for two hours, and then stored in a dark place for 22 hours. A distillated ice-water (400 mL) was added and the organic layer was extracted with chloroform (2 × 50 mL), washed with distillated water (3 × 100 mL), and then dried over anhydrous magnesium sulfate (MgSO4), filtered and solvent removed under reduced pressure, and a syrup residue was left which then treated with a few drops of petroleum ether to give (3.78 g, 57%) of the ligand as a yellow solid. Rf =0.42. m.p = 124C. (C.H.N); Found (Calc.): C% = 57.48(58.62), H% = 3.97(4.59), N%= 0. Synthesis of complexes General method To an ethanolic solution of ligand (2 mmol) in ethanol (15 mL) was added with stirring an ethanolic solution (10 mL) of the metal salt (1 mmol). The reaction mixture was allowed to reflux for 4 h, resulting in the formation of coloured precipitate. This was then collected by filteration, and washed with (5 mL) diethyl ether and dried at room temperature. Table (1) shows the stated weight of starting materials, yield and some physical properties of the prepared complexes. Results and Discussion The derivative-A 5,6-O-benzylidene L-ascorbic acid (scheme1) was obtained from the reaction of L-ascorbic acid with (two mole) of benzaldehyde and anhydrous Zinc chloride. The compound was characterised by IR and 1H NMR spectra. The IR spectrum shows characteristic two bands at (1739, 1604) cm-1 due to (C=O) and (C=C) lactone, respectively. The four bands in the free L-ascorbic acid which assigned to the hydroxyl groups are no longer exist in IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 compound-A. The spectrum shows two bands at (3448) and (3445)cm -1 assigned to (O–H) at positions (C3) and (C2), respectively. Also the spectrum shows two bands at (3066)cm-1 and (1408)cm -1 assigned to (C–H) and (C=C) aromatic ring, respectively. This is due to block of the hydroxyl groups at (C5) and (C6) positions by benzaldehyde and forming 5,6-O-cyclic acety l derivative [20,21,22]. Fig (1) exhibits the (IR) spectrum for the derivative-A. The 1H NM R spectrum of (A) shows the following signals: doublet at δ(3.9- 4.0) ppm assigned to the protons of (–CH2) at (C6) position, quartet at δ(4.1 - 4.4) ppm assigned to the proton of the (–CH) of (C5) position, doublet at δ(5.6 - 5.7) ppm assigned to the proton of (-CH) at (C4) position. The chemical shift at δ (10) ppm assigned to the proton of the hydroxyl group at (C2) and (C3) positions, these protons shifted to a lower frequency (deshielding) due to the resonance between the (-OH) group at (C2) and (C3) with the (C=O) lactone ring. The singlet at δ(6.2) ppm was assigned to the proton of a cyclic ring at (C7) position. This proton shifted to a lower frequency due to the bonded with the two oxygen atoms. The chemical shifts at δ(7.3 - 7.9) ppm were assigned to the protons of the aromatic ring, equivalent to 5 protons. The appearance of the protons at (C7) position and aromatic ring as a result to the blocking of the two hydroxyl groups at (C5) and (C6) positions by benzaldehyde to form the derivative-A [23,24]. Fig.(2) exhibits the (1 H NMR) for the derivative-A. Scheme(1):The synthesis route of the derivative 5,6-O-benzylidene-L-ascorbic acid (A) The reaction of the derivative-A 5,6-O-benzylidene-L-ascorbic acid dissolving in anhydrous pyridine with the acety l chloride offered the new ester [2,3-O-diacety l-5,6-O-benzylidene-L- ascorbic acid][L] (scheme 2). The ligand was characterised by elemental analysis (Table 1), IR (Table 2), UV-Vis (Table 3) and 1H NMR (Table 4) spectroscopy. The IR spectrum of the ligand Fig.(3) shows characteristic bands at (1739,1627 and 1496) cm -1 due to the (C=O) lactone, (C=C) aliphatic and (C=C) aromatic functional group respectively. The new band at (1670) cm-1 due to the ester group. The appearance of this new band as a result to the formation of the ester at (C2) and (C3) positions by acety l chloride. The two bands in the derivative (A) at (3445 and 3448) cm-1 which are due to the hydroxyl group at (C2) and (C3), these two bands disappeared in the new ligand due to the formation of ester[20,21,22]. The (UV-Vis) spectrum of the ligand [L] Fig.(4) exhibits an intense absorption peak at (274) nm, assigned to ( → *). A hump at (370) nm assigned to (n → *) transition[25]. The 1 H NM R spectrum of the ligand [L] Fig.(5) shows a new peak at δ(1.7-2.3) ppm assigned to the protons of (-CH3) in the ester. This is equivalent to six protons. The appearance of a new peak indicating to the formation of ester at OHO H O O H O C H O ZnCl2 OO O OH OH 1 23 4 5 6 7 HOHO IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 (C2) and (C3) positions by acety l chloride. In addition the chemical shift at δ(10) ppm in the derivative [A] which is assigned to the proton of (-OH) group at (C2) and (C3) positions, this peak disappearance in the 1H NM R spectrum of the new ligand as a result to the formation of ester[23,24]. Scheme(2): The synthesis route of the ligand [L] 2,3-O-diacety l-5,6-O-benzylidene-L-ascorbic acid All complexes were prepared by similar methods from the reaction of the ligand [L] with the metal chloride salts at reflux in ethanol medium and pure complexes were formed. The (IR) spectrum of the complexes Cr III ,CoII ,NiII ,CuII and ZnII are shown in Figures 6, 7, 8, 9, 10, respectively. The absorption bands at the range (3383-3456) cm-1 and (819-925) cm -1 were assigned to the H2O aqua for the complexes CrIII, NiII, CuII and ZnII ,indicating to the coordination of the H2O molecule with the metal ion . The absorp tion band at (1670) cm-1 in the free ligand which was assigned to the (C=O) ester, was shifted to a lower frequency in the complexes and appeared at the range (1624 - 1635) cm-1, indicating a reduction in the bond order. This can be attributed to the delocalization of metal electronic density at (t2g) in the  - system of the ligand. In addition, the complexes showed new bands in the region (418 - 493)cm-1 which are due to the formation of M–O bonds, indicating that the oxygen of ester group is involved in coordination with metal ions [26]. Other bands of the (IR) spectral data are summarized in Table (2). The molar conductance of the complexes in (DM F) Table (3) laid in the range (77.5-84.6 S.cm2.mole-1) for complexes NiII and CuII, indicating their electrolytic nature with (1:1) ratio. The conductance measurements in the range (146.2-152.8 S.cm2 mole -1 ) for complexes Co II and Zn II , indicating their electrolytic nature with (1:2) ratio. While the molar conductance of the complex CrIII was (231.5 S.cm2.mole-1), indicating its electrolytic nature with (1:3) raito [27]. The electronic absorption spectra Figures 11, 12, 13, 14 and 15 of the complexes CrIII, CoII, NiII, CuII and ZnII , respectively were recorded at room temperature using (DM F) solutions. The absorp tion spectra for these complexes show intense peaks in the range (274-281) nm, which may be related to the ligand field, while the peaks in the range (350-372) nm, assigned to charge transfer. The (UV-Vis) spectra of CrIII and Cu II exhibited another peaks at visible region at (873 and 825) nm, respectively. These peaks were assigned to (4A2g→ 2T2g) and (2B2g →2A1g) (d-d) transitions for complexes CrIII and CuII respectively, confirming a distorted octahedral geometries. The (UV- Vis) spectra of NiII complex exhibited another two peaks in the visible region at (677 and 833) nm. These peaks were assigned to (3 A2g → 1 Eg) (d-d) transition, confirming octahedral structure. OO O OH OH H 3C C Cl O Pyridine OO O O O O H C CH3 C H3C O 1 23 4 5 6 7 OHO IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 The (UV-Vis) spectra of Co II complex exhibited two peaks at visible region at (608 and 672) nm. These peaks were assigned to (4 A2 → 4 T1(p)) (d-d) transitions, confirming tetrahedral geometry[25]. At last the (UV-Vis) spectra of ZnII displayed peak at (276) nm assigned to ligand field transition, since the metal ion of the compound belong to d10 system. The suggested structure of the complexes are shown in the (scheme 3). The results are summarized in Table (3). References 1.Zümreoglu-Karan, B. (2006) “The Coordination Chemistry of Vitamin C: An over review” Coordination Chemistry Reviews, 250:- 2295-2307. 2.González, M.J. et. al. (2005) “Orthomolecular Oncology Review: Ascorbic acid and Cancer 25 Years Later” Integrative Cancer Therapies, 4(1): 32-44. 3.Ralph, W.A. and Bert, M. T. (1971) “Synthesis of 5,6-O- Alkylidene Derivatives of L-Ascorbic Acid By The Orthoformate Method” Org. Prep. Proced. Int., 3(6):229. 4.Jin, S. and Miao, X. (2008) “3-O-Ethyl-L-ascorbic acid” Acta Cryst., E64:- o860. 5.Sakagami, H.; Asano, K.; Fukuchi, K.; Gomi, K.; Ota, H.; Kazama, K.; Tanuma, S. and Kochi, M. (1991) “Induction of Tumor Degeneration By Sodium Benzylidene Ascorbate” Anticancer Res., 11(4): 1533-1538. 6.Pettersen, E.; Larsen, R.; Boerretzen, B.; Dornish, J. and Oftebro, R. (1991) “Effect on Protein Synthesis and Cell Survival of The Benzaldehyde Derivatives (SBA) and The Deuterated Compound Zilascorb (2H)” Anticancer Res. 11(3):1077. 7.Semb, K.; Fodstad, O.; Klem, B.; Bibow, K.; Osmundsen, K. and Aamdal, S. (1997) “Zilascorb(2H), A New Reversible Protein Synthesis Inhibitor: Clinical Study of an Oral Preparation” Anticancer Drugs, 8 (3):296. 8.Satoh, K. and Sakagami, H. (1997) “Effect of Cysteine , N-Acetyl-L-Cysteine and Glutathione on Cytotoxic Activity of Antioxidants” Anticancer Res., 17 (3C): 2175. 9.Nihro. Y.; Sagawa, S.; Izumi, A.; Sasamori, A.; Sudo, T.; Miki, T.; Matsumoto, H. and Satoh, T. (1992) “3-O-Alkyl Ascorbic Acid as Free Radical Quenchers. 3.Protective Effect on Coronary Occlusion-Reperfusion Induced Arrhythmias in Anesthetized rats” J. Med. Chem., 35(9):1618- 1623. 10.Tripathi, R. P.; Singh, B.; Bisht, S. S. and Pandey, J. (2009) “L-Ascorbic Acid in Organic Synthesis: An Overview” Current Organic Chemistry, 13: 99-122. 11.Kojima, S.; Yamaguchi, H.; Morita, K. and Ueno, Y. (1995) “Inhibitory Effect of Sodium 5,6- Benzylidene Ascorbate (SBA) on the Elevation of Melanin Biosynthesis Induced by Ultraviolet- A (UV-A) Light in Cultured B-16 Melanoma Cells” Biol. Pharm. Bull., 18 (8):1076-1080. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 12.Kishino, K.; Hashimoto, K.; Amano, O.; Kochi, M.; Liu, WK. and Sakagami, H. (2008) “Tumor-Specific Cytotoxicity and Type of Cell Death Induced by Sodium 5,6-Benzylidene-L- Ascorbate” Anticancer Res., 28(5A): 2577-2584. 13.Ariyoshi-Kishino, K.; Hashimoto, K.; Amano, O.; Saitoh, J.; Kochi, M. and Sakagami, H. (2010) “Tumor-specific Cytotoxicity and Type of Cell Death Induced by Benzaldehyde” Anticancer Res., 30(12):5069-5076. 14.Takebayashi, J.; Tai, A.; Gohda, E. and Yamamoto, I. (2006) “Characterization of the Radical-Scavenging Reaction of 2-O-Substituted Ascorbic acid Derivatives, AA-2G, AA-2p and AA-2S: Kinetic and Stoichiometric Study” Biol. Pharm. Bull., 29 (4): 766-771. 15.Austria, R.; Semezato, A. and Bettero, A. (1997) “Stability of Vitamin C Derivatives in Solution and Topical Formulations” J. Pharma. Biomed. Anal., 15(6):795-801. 16.Chang, M. and Chang, C. (2005) “Simultaneous Voltammetric Determination of Ascorbic Acid and Its Derivatives in Cosmetics Using Epoxy-Carbon Composite Electrodes” Journal of Food and Drug Analysis, 13 :-No.3, 205-211. 17.Tajmir-Riahi, H. A. (1990) “Coordination Chemistry of Vitamin C. Part I. Interaction of L- Ascorbic Acid with Alkaline Earth Metal Ions in the Crystalline Solid and Aqueous Solution” J. Inorg. Biochem., 40 :-181-188. 18.Martell, A. E. (1982) “In Ascorbic Acid: Chemistry, Metabolism and Uses” American Chemical Society, Washington, Dc., 153-178. 19.Ünaleroğlu, C.; Mert, Y. and Zümreoğlu-Karan, B. (2001) “Synthesis and Characterization of Copper Ascorbate” Synth. React. Inorg. Met - Org. Chem., 31 (9):1531-1543. 20.Morrison, RT. and Boyd RN., (2007) "Organic Chemistry" 6thEd, New York University . Kemp, W. (1987) "Organic Spectroscopy" 2 nd Ed, 144. 21.Silverstein, R. M.; Bassler, G.C. and Morrill, T. C., (1981) “Spectrometric Identification of Organic Compounds” 4 th Ed., John Wiley and Sons, New York. 22.Sharma, Y. R. (2009) “Elementary Organic spectroscopy” Multicolour Edition, India. 23.Fleming and Williams, D. H., (1966) “Spectroscopic Methods in Organic Chemistry” ed. McGraw Hill Publishing Company Ltd., London. 24.Lever, A.B. P. (1984) “Inorganic Electronic Spectroscopy” 2 nd Ed, New York. 25.Nakamoto, K. (1996) “Infrared Spectra of Inorganic and Coordination Compounds” 4 th Edition, John Wiely and Sons, New York. IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 26.Geary, W. J. (1971) “The Use of Conductivity Measurements in Organic Solvent for the Characterisation of Coordination Compounds” Coord. Chem. Rev., 7 :-81. Table (1) :some physical properties of the complexes and its reactants quantities Compound m. p C M. wt Color Weight of metal chloride(g)=(0.1 1)mmole Weight of product (g) Yield % Chlori de conten t Metal ion % Prac.(The o.) Derivative - A 16 3 264 Pa Pale yellow - 2.93 39% - - [L] 12 4 348 Yello w - 3.78 57% - - [Cr(L)2(H2O)2 ]Cl3 10 8 890 .35 Green 0.030 0.15 73% 11.6 (11.9) 5.60 (5.83) [Co(L)2]Cl2 10 7 825 .83 Dark Brown 0.027 0.13 68% 8.41 (8.58) 6.97 (7.13) [Ni(L)2(Cl)(H 2O)]Cl 10 4 843 .60 Green 0.027 0.10 51% 7.91 (8.40) 6.63 (6.95) [Cu(L)2(Cl)(H 2O)]Cl 10 2 848 .40 Brown 0.019 0.17 87% 8.19 (8.35) 7.36 (7.48) [Zn(L)2(H2O)2 ]Cl2 10 4 868 .31 Yello w 0.015 0.11 55% 8.07 (8.16) 7.40 (7.53) IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Table (2) :IR spectral data of the ligand and its complexes Compound (C=O) lactone (C=O) ester (C=C) lactone (C=C) aromatic M- O Other bands Derivative - A 1739 - 1604 1408 - 2981(C- H)alipha 3066(C- H)aroma 3445(C(2)-OH) 3448(C(3)-OH) [L] 1739 1670 1627 1496 - 2927(C- H)alipha 3066(C- H)aroma [Cr(L)2(H2O)2]Cl3 1732 1635 1608 1417 486 2935(C- H)alipha 3010(C- H)aroma 3404, 898 H2O aqua [Co(L)2]Cl2 1732 1635 1616 1456 487 2926(C- H)alipha 3197(C- H)aroma [Ni(L)2(Cl)(H2O)]Cl 1732 1624 1622 1406 470 2852(C- H)alipha 2926(C- H)aroma 3383, 920 H2O aqua [Cu(L)2(Cl)(H2O)]Cl 1732 1635 1618 1409 493 2927(C- H)alipha 2983(C- H)aroma 3456, 819 H2O aqua [Zn(L)2(H2O)2]Cl2 1734 1635 1618 1456 418 2997(C- H)alipha 3147(C- H)aroma 3456, 925 H2O aqua IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Table (3): Electronic Spectral data and Conductance measurements of the ligand and its complexes Compound λ(nm) εmax (molar -1 cm-1 ) Λm (S.cm 2 .mol -1) Ratio Proposed Structure [L] 274 370 1887 870 - - - [Cr(L)2(H2O)2]C l3 274 350 873 1852 581 6 231.5 1:3 Octahedral [Co(L)2]Cl2 281 360 608 672 2350 562 82 103 146.2 1:2 Tetrahedral [Ni(L)2(Cl)(H2O )]Cl 281 372 677 833 2409 570 22 9 77.5 1:1 Octahedral [Cu(L)2(Cl)(H2 O)]Cl 281 353 825 2428 522 28 84.6 1:1 Octahedral [Zn(L)2(H2O)2] Cl2 276 1920 152.8 1:2 Octahedral IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Table (4): 1H NMR data for the ligand measured in DMSO and chemical shift in ppm(δ) O O O O O O H C H3C C H3C O O O O O O O O H C CH3 C CH3 O O M X Y Cln Octahedral M= Cr III , X=Y=H2O,n=3 Ni II and CuII, X=Cl, Y=H2O,n=1 ZnII, X=Y=H2O,n=2 compound δ(C(6) - H) δ (C(5)- H) δ (C(4)- H) δ (C(7)-H) δ (-CH3) δ (C-H) aromatic δ (O- H) Derivative - A 3.9- 4.0 4.1 - 4.4 5.6 - 5.7 6.2 - 7.3 -7.9 10 Ligand [L] 4.0 - 4.1 4.3 - 5.1 5.4 - 5.7 6.1 1.7 - 2.3 7.4 - 8.5 - IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 O O O O O O H C H3C C H3C O O O O O O O O H C CH3 C CH3 O O Co Cl2 Tetrahedral Scheme (3) :The suggested structure for the complexes IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Fig.(1): The IR. Spectrum of the Derivative [A] Fig.(2): The 1H NMR Spectrum of the Derivative [A] Fig.(3): The IR. Spectrum of the Ligand [L] Fig.(4) :The 1H NMR Spectrum of the Ligand [L] Fig.(5): The UV-Vis Spectrum of the ligand [L] IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Fig.(6) :The IR. Spectrum for [Cr(L)2(H2O)2]Cl Fig.(7) :The IR. Spectrum for [Co(L)2]Cl2 Fig.(8) :The IR. Spectrum for [Ni(L)2(Cl)(H2O)]Cl Fig.(9):The IR. Spectrum for [Cu(L)2(Cl)(H2O)]Cl Fig.(10): The IR. Spectrum for [Zn(L)2(H2O)2]Cl2 IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Fig.(11): The UV-Vis Spectrum for [Cr(L)2(H2O)2]Cl3 Fig.(12) :The UV-Vis Spectrum for [Co(L)2]Cl2 Fig.(13): The UV-Vis Spectrum for [Ni(L)2(Cl)(H2O)]Cl IBN AL- HAITHAM J. FOR PURE & APPL. SCI. VOL.24 (3) 2011 Fig.(14): The UV-Vis Spectrum for [Cu(L)2(Cl)(H2O)]Cl Fig.(15): The UV-Vis Spectrum for [Zn(L)2(H2O)2]Cl2 2011) 3( 24المجلد مجلة ابن الهیثم للعلوم الصرفة والتطبیقیة ند جدیداتشخیص لیكتحضیر و 2,3-O-di Acetyl-5,6-O-Benzylidene - L -Ascorbic Acid أیونات العناصرومعقداته مع Cr(III), Co(II), Ni(II),Cu(II),Zn(II) أسراء شكیب عبد الرزاق القاضي دا ة، كلیة التربیقسم الكیمیاء بن الهیثم، جامعة بغدا الخالصة O2([2,3-O-di Acety( ند جدید من نوعاتضمن البحث تحضیر لیك l-5,6-O-Benzylidene-L-AscorbicAcid] حضر المشتق الخطوة االولى، حضر بخطوتین نداهذا اللیك Cln[M(L)2(X)(Y)]الصیغة يومعقداته ذ [5,6-O-benzylidene-L-ascorbic acid] (A) . المشــتق(A) ـل بـــالخطوة الثانیــة مــع كلوریـــد االســت والبریـــدین یلاتفاعـ تــم Zn(II) و Cr(III), Co(II), Ni(II),Cu(II)معقـدات العناصــر . نــد المطلــوباللحصــول علـى اللیك الالمـائي كقاعــده ه باسـتاشـخص اللیك. نـد اتحضیرها من التفاعل المباشر بین ملح كلوریـد الفلـز مـع اللیك االشـعة (ق الطیفیـة ائـالطر المعنـد ومعقداتـ ـــرنین النــووي المغناطیســـي للیك، تحــت الحمــراء التحلیــل الـــدقیق للعناصــر والتوصـــیلیة ). [A]وللمشـــتق [L]نــد افـــوق البنفســجیة وال ,Cr(III)ومـن النتـائج اعـاله فـأن الشــكل الفراغـي للعناصـر . نــداللیك (C.H.N)االنصـهار وقیـاس قیـاس درجـات، الكهربائیـة Ni(II),Cu(II)و Zn(II) هي ثمانیة السطوح بینما معقدCo(II) كان الشكل الفراغي هو رباعي السطوح. .ر المضاد للسرطانالتأثی، معقدات األسكوربیت، حامض األسكوربیك، بنزالیدین، أستر :الكلمات المفتاحیة