Microsoft Word - 89-101 89 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Synthesis, Characterization and Spectral Studies of Y(III), La(II) and Rh(III) Complexes with 2,4-dimethyl-6-(4-nitro-phenylazo)- Phenol . Amer J. Jarad Dhafir T. A. Alheetimi Sumayha M. Abass Rasha A. Hashim Dept. of Chemistry/ College of Education for Pure Science (Ibn-Al Haitham)/ University of Baghdad Received in:5/May/2015،Accepted in:30/June/2015 Abstract Transition metal complexes of Y(III), La(III) and Rh(III) with azo dye 2,4-dimethyl-6- (4-nitro-phenylazo)-phenol derived from 4-nitroaniline and 2,4-dimethylphenol were synthesized. Characterization of these compounds has been done on the basis of elemental analysis, electronic data, FT-IR,UV-Vis and 1HNMR, as well as conductivity measurements. The nature of the complexes formed were studies following the mole ratio and continuous variation methods, Beer's law obeyed over a concentration range (1x10-4- 3x10-4). High molar absorbtivity of the complex solutions were observed. From the analytical data, the stoichiomerty of the complexes has been found to be 1:3 (Metal:ligand). On the basis of Physicochemical data octahedral geometries were assigned for the complexes. Key words: complexes, transition metals, spectral studies, azo dyes. 90 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Introduction Synthetic dyes produced in large quantities are extensively used in paper printing, textile dyeing, pharmaceutical, food, color photography, cosmetics, textile and other industries[1-3]. For many years the azo compounds have been the main class of dyes used in various applications such as textile fibers dyeing and coloring of different materials and advanced organic synthesis [4-7]. Several bidentate azo dyes in which the phenolic-OH group and azo nitrogen are present in such a way that they form six membered ring with metal ions are published [8].The vast applications of azo dyes have inspired the modern chemists to prepare new metal chalets by reacting with new poly dentate azo dyes with different transitional and non-transitional metal ions[9].Recently metal complex dyes have also attracted increasing attention due to their increasing electronic and geometrical features in connection with their application for molecular memory storage[10].This work presents the synthesis of an azo dye derived from 4-nitro aniline as diazo component and 2,3- dimethylphenol as coupling agent.Complexes of this ligand (L) with Y(III), La(III) and Rh(III) have also been studied and characterized physicochemical. Experimental Instrumentations UV- Vis spectra were recorded on a Shimadzu UV- 160A Ultra Violet-Visible Spectrophotometer. IR- spectra were taken on a Shimadzu, FT-IR- 8400S Fourier Transform Infrared Spectrophotometer in the 4000- 400 cm-1 spectral regions with samples prepared as KBr discs. Atomic absorption was obtained using a Shimadzu A.A-160A Atomic Absorption/Flame Emission Spectrophotometer. The 1H-NMR spectra were recorded on a Brucker-300 MHz Ultra Shield spectrometer at University of Al- al- Bayt using DMSO as the solvent and TMS as the reference. Micro elemental analysis (C.H.N) was performed at the Al- al- Bayt University, Jordan, using Euro vector EA 3000A Elemental Analyser. Conductivities were measured for 10-3 M solutions of complexes in ethanol at 25оC using Philips PW- Digital Conductmeter. In addition, melting points were obtained using Stuart Melting Point Apparatus. Materials and Reagents The following chemicals were used as received from suppliers: Yttrium nitrate pentahadrate (99.9%), Lanthanum chloride nonahydrate (98.8%) and Rhodium chloride monohydrate (98.8%) (Merck), 4-nitroaniline and 2,4-dimethylphenol (B.D.H). Preparation of 2,4-Dimethyl-6-(4-nitro-phenylazo)-phenol Ligand (L) A solution of 4-nitroaniline[11] (0.342g, 1mmole) (10ml) of EtOH solution contain (2ml) conc.H2SO4 was diluted with 10 ml H2O, and diazotized at 5oC with NaNO2 solution. The diazo solution was added drop wise with stirring to a cooled ethanolic solution of (0.305g, 1mmole) of 2,4-dimetylphenol. 25 ml of 1M sodium hydroxide solution was added to the dark colored mixture. The precipitate was filtered, washed several times with (1:1) ethanol: water, mixture then left to dry. The reaction is shown in scheme (1), while Table (1) describes the physical properties and elemental micro analysis. 91 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Scheme (1) Buffer Solution Buffer solution, covering the pH range of 4-9, were prepared as 0.01 M solutions of ammonium acetate in distilled water. The required pH was obtained by the addition of either ammonia solution or glacial acetic acid. Metal Salt Solutions Solutions of (1x10-5- 1x10-3 M) of the metal salt were prepared by dissolving appropriate weight of the metal salt in the buffer solutions. Ligand Solution Ligand solutions of (1x10-5- 1x10-3 M) were prepared by dissolving a required weight of the ligand in ethanol. Preparation of Metal Complex (general procedure) An ethanolic solution of the ligand (L) (0.271g, 3mmole) was added gradually with stirring to the 0.120g, 0.134g and 0.075g of Y(NO3)3.5H2O, LaCl3.9H2O and RhCl3.H2O dissolved in the buffer solution with the required pH. The mixture was cooled until dark color precipitate was formed, filtered, and washed several times with 1:1 water: ethanol mixture, then with acetone. NH2O2N O2N N2 + N aO H NO2N N HO CH3 CH3 10% NaNO2 H2SO4 Conc 2 ,4 -d i m e th y lp h en o l 92 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Results and Discussion The ligand 2,4-Dimethyl-6-(4-nitro-phenylazo)-phenol (L) was prepared by coupling 2,4- dimethylphenol with the 4-NO2.Phenol.diazonium in alkaline solution. The ligand (L) was sparingly soluble in water but soluble in organic solvents such as DMSO and DMF, stable toward air and moisture. Synthesized ligand (L) was characterized by 1HNMR, FT-IR, Elem.Anal. (C.H.N) and UV- Vis spectroscopic technique. The 1HNMR spectrum of the ligand in DMSO (Figure 1) shows multiplet signal at δ=7.36-7.77 ppm, which refers to aromatic protons[12] . A signal at δ = 4.32 ppm appears due to hydrogen atom of the phenolic group[13]. The signal at δ= 3.33 ppm is assigned to δ(CH3) and the signal at δ=2.50 ppm referred to DMSO-d6 [14]. Interaction of the metal ions (YIII, LaIII and RhIII) with the prepared ligand (L) has been studied in solution; an aqueous- ethanolic solution was always performed over wide molar concentration and acidity range. Colours of these mixed solutions were varied from brown to yellow. Different ranges of molar concentrations (10-5-10-3 M) of the mixed solutions, only concentrations in the range of 10-4 M obey the Lambert- Beer's law, and only these solutions showed intense colour. A calibration curve was fitted to data points in the range 1.10-4 – 3.10-4 M, which shows absorbance against molar concentration (Figure 2). Best fit straight lines were obtained with correlation factor of R> 0.998. The optimal concentration was chosen for complex solutions, and it was observed that the absorption maximum (λmax) remained the same at different pH values. The influence of pH was also studied in the pH range of 4-8, and the absorbance- pH curves for each metal ion measured at λmax are plotted in Figure(3). Figure (3) shows selective pH-absorbance curves. The plateaus of the curves represent the completion of the reaction and consequently represent the optimum pH value. The composition of complexes formed in solutions has been established by mole ratio and job methods. In both cases the results reveal a 1:3 metal to ligand (L) ratio. A selected plot is presented in Figure (4). Table( 2) summarizes the results obtained, as well as conditions for the preparation of the complexes. The solid complexes have been prepared by direct reaction of alcoholic solution of the ligand (L) with the aqueous solution of the metal ions at the optimum pH and in a M:L ratio of 1:3. The result of C.H.N analysis and the metal content of these complexes were in good agreements with the calculated values. The molar conductance of 10-3 M in ethanolic solutions of these complexes indicated their non- electrolytic type[15] , data are presented in Table 2.The UV- Vis spectrum of an ethanolic solution of the ligand 10-3 M displayed mainly two peaks, the first was observed at 350 nm due to the moderate energy π- π* transition of the aromatic rings and the second peak was observed at the 422 nm was referred to the n-π* transition of (-N=N) group[16]. The spectra of the prepared complexes dissolved in ethanol 10-3 M have been measured and the data obtained are included in Table (2). The large bathchromic shift of the absorption maximum (λmax), assigned to (n-π*) transition of the ligand (L), suggests the involvement of the ligand (L) in the bond formation with the metal ion. Figure 5 showed a comparison between the spectra of the ligand and Rh(III) complex. In order to study the bonding mode of the ligand (L) with the metal ion, the FT-IR spectra of the free ligand (L) and the prepared complexes have been compared, and the data was tabulated in Table (3). The IR spectrum of the ligand (Figure 6) exhibited broad band at 3462 cm-1, which was assigned to the stretching vibration of υ(OH) group. This band was absent in the spectra of the prepared complexes (Figure 7), which indicated deprotonation and involvement of the enol oxygen in chelation[17,18]. Bands characteristic of the azo bridge vibration at 1489 cm-1 and 1429 cm-1 shifted to lower frequency with change in shape in spectra of the complexes, which is an indication of the engagement of this group in the coordination with the metal ion[19]. The appearance of new bands in the region (482-572) cm-1 are tentatively assigned to υ(M-N) and υ(M-O) (Metal-Ligand) stretching bands[20,21]. 93 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 According to the results obtained, an octahedral structure has been tentatively suggested to rhodium complex. References 1. Kirkan,B. and Gup,R.(2008) Synthesis of new azo dyes and copper (II) complexes derived from barbituric acid and 4-aminobenzoylhydrazone,Turk.J.Chem.; 32 ,9-17. 2. Raghavendra,K.R. and Kumar,K.A.(2013) Synthesis of some azo dyes and their deying, redox and antifungal properties, Inter.J.Chem.Techno.Res.; 5, 4, 756-1760. 3. Lemr,K.;Holcapek,M.;Jandera,P. and .Lycka,A. (2000) Analysis of metal complex azo dyes by high performance liquid chromatography / electrospray ionization mass spectrometry and multistage mass spectrometry; Rapid Commun.Mass Spectrom.;14,1881-1888. 4. Turcas,C.V. and Sebe,I. (2012) Azo dyes complexes, synthesis and tinctroial properties, U.P.B.Sci.Bull.; 74, 1,109-118. 5. Hrdina,R.;Lustine,D.;Stolin,P.;Burgert,L.;Lunak,S. and Holcapek,M. (2004) Iron complexes of reactive azo dyes, Advan.Color.Sci.Techn.; 7,1,6-17. 6. Patel,V.H.;Patel,M.P. and Patel,R.G. (2002) Synthesis and application of novel heterocyclic dyes based on 11-amino-13H-acenaphtho [1,2-e] pyridazino [3,2-b] quinazolin-13-one, J. Serb. Chem. Soc.; 67, 11, 727-734. O CH3 CH3 N NO2N N N O H3C H3C O CH3 N N H3C M NO2 NO2 M = Y(III), La(III) and Rh(III) 94 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 7. Taura,Y.B.;Gumel,S.M.;Habibu,S. and Adam,J.L.(2014) Synthesis of cobalt complex azo dye from 2,2[benzene-1,3-diyl di-(E)-diazene-2,1-diyl] bis(4-nitroaniline), IOSR J.Appl.Chemm.; 7,8,34-37. 8. Modhavadiya,V.A. (2011) Synthesis, characterization and antimicrobial activity of metal complexes containing azo dye ligand of sulfa drugs, Asian J.Biochemm.Pharm.Res.;11,1,173-179. 9. Mahapartra,B.B. and Panda,S.K.(2010) Coordination compounds of CoII,NiII,CuII,ZnII,CdII and HgII with tridentate ONS doner azo dye ligands, Biokemistri; 22,2,71-75. 10. Dharmalingm,V.;Ramasamy,A.K. and Balasuramanian,V. (2011) Synthesis and EPR studies of copper metal complexes of dyes derived from remazol red b,procino yellow, fast green FCF, brilliant cresyl blue with copper acetate monohydrate, E.J.Chem.; l., SI, S211-S224. 11. Naik,S.J. and Halkar,U.P. (2005) Synthesis and application of novel 4,5,6,7- tetrahydrobenzothiazole based azo disperse dye, General Papers,Airkivoc; xiii, 3, 141- 149. 12. Carballo,R.;Castineiras,A.;Covelo,B.;Niclos,J. and Vazguez-Lopez,E. (2001) Synthesis and characterization of potassium complex of magneson: [K(HL)(OH2)2][H2L=4-(4- nitrophenylazo) resorcinol (Magneson)], Polyhedron 20, 2415-2420. 13. Bartta,P. (2006) Sulpher bridged ruthenium-molybdenum complexes:(R-aapm) 2Ru(µ- S)2Mo(OH)2] synthesis, spectroscopic and electrochemical characterization. R-aapm = 2- (arylazo)pyrimidine; J.Chem.Sci, 118, 2, 171-177. 14. Pal,S. and Sinho,C. (2001) Studies on the reactivity of cis-RuCl2 fragment in Ru(pph3)2(TaiMe)Cl2 with N,N-chelators (Taime=1-Methyl-2-(p-Tolylazo) Imidazole). spectral and electrochemical characterization of the products, Proc. Ind. Acad. Sci ; 113, 3, 173-182. 15. Geary,W.J. (1971) Characterization of coordination compounds, Coord.Chem .Rev.; 7, 110. 16. Anitha,K.R.;Venugopala,R. and Rao,V.R.S. (2011) Synthesis and antimicrobial evaluation of metal (II) complexes of a novel bisazo dye 2,2 [benzene-13- diyl di (E) diazene 2,1-diyl] bis (4-chloroaniline)", J.Chem.Pharm.Res.; 3, 3, 511-519. 17. Karipcin,F. and Kabalcilar,E. (2007) Spectroscopic and thermal studies on solid complexes of 4-(2-pyridylazo)-resorcinol with some transition metals, Acta.Chim.Slov.; 54, 242-247. 18. Yildiz,E. and Boztepe,H. (2002.) Synthesis of novel acidic mono azo dyes and an investigation of their use in the textile industry, Turk.J.Chem.; 26, 897-9030. 95 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 19. Oututu,J.O. (2013) Synthesis and application of azo dyes derived from 2-amino-1,3,4- thiadiazole-2-thiol on polyester fibre, IJRRS; 15, 2, 292-296. 20. Raman,N.;Raja,J.D. and Sakthivel,A. (2007) Synthesis, spectral characterization of Schiff base transition metal complexes: DNA cleavage and antimicrobial activity studies, J.Chem.Sci.; 119, 4, 303-310. 21. Rajavel,R.;Vadivu,M.S. and Anitha,C. 2008) Synthesis, physical characterization and biological activity of some Schiff base complexes, E.J.Chem.; 5, 3, 620-626. Table (1): Physical properties and elemental analysis of the ligand and it,s complexes. Compounds Color M.P°C Yield % Analysis Calc (Found) M% C% H% N% Ligand(L) Orange 246 82 - 61.99 (60.95) 4.79 (3.81) 15.49 (14.53) [Y(L)3] Brown 280 68 24.38 (23.74) 56.06 (55.73) 4.00 (3.95) 14.01 (13.75) [La(L)3] Deep brown 325 71 14.64 (13.96) 53.10 (52.58) 3.79 (2.93) 13.27 (12.88) [Rh(L)3] Deep yellow >360 73 11.28 (10.93) 55.20 (54.88) 3.94 (3.15) 13.80 (12.63) 96 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Table (2): Conditions for the preparation of the complexes and UV-Vis, conductance measurements data. Compound s Optimum pH Optimum Molar Conc. 4-x 10 M:L Ratio )max(λ nm ABS maxЄ )1-.cm1-(L.mol ) 1-.mol2(S.cmmΛ In Absolute ethanol Ligand(L) - - - 350 422 1.951 1.176 1951 1176 - [Y(L)3] 8 2 1:3 394 547 0.836 0.381 836 381 18.37 [La(L)3] 7 2.5 1:3 348 490 0.926 0.627 926 627 12.85 [Rh(L)3] 7 2.5 1:3 284 395 530 969 1.472 0.483 1.371 1.126 1472 483 1371 1126 16.24 97 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Table (3): The main frequencies of the ligand and it,s complexes (cm-1). br = broad, s= strong, , sh = sharp, w = weak Figure (1): 1HNMR spectrum of the ligand. Compounds ν (OH) ν(-N=N-) ν (M-N) ν (M-O) Ligand(L) 3462 br. 1489 sh. 1427 Sh. - - [Y(L)3] - 1462 sh. 1418 s. 572 w. 485 w. [La(L)3] 1470 s. 1420 s. 567 w. 494 w. [Rh(L)3] - 1450 s. 1420 s. 553 w. 482 w. 98 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Figure(2): Linear relation between molar Figure(3): Effect of pH on absorbance concentration and absorbance. (λmax) for complexes. Figure (4): Mole ratio and Job methods for complex solution. 99 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Figure ( 5): UV-Vis spectra of free ligand and RhIII complex 100 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 Figure (6): FT-IR spectrum of the ligand.  Figure (7): FT-IR spectrum of the [Rh(L)3] complex. 101 | Chemistry 2016) عام 1(العدد 29المجلد مجلة إبن الهيثم للعلوم الصرفة و التطبيقية Ibn Al-Haitham Jour. for Pure & Appl. Sci. Vol. 29 (1) 2016 ) والروديوم III)، الالنثانيوم(IIIتحضير وتشخيص ودراسة طيفية لمعقدات الليتيريوم ( )III فينول - فنيل آزو) –نيترو-4( -6-ثنائي مثيل -2،4) مع عامر جبار جراد الهتيمي ظافر تموين عجيل سمية محمد عباس رشا احمد هاشم جامعة بغداد /)ابن الهيثم (كلية التربية للعلوم الصرفةجامعة بغداد/ 2015/حزيران/30في :،قبل 2015/مارس /5استلم في: الخالصة فنيل –نيترو -4( - 6-ثنائي مثيل - 4،2الليتيريوم، الالنثانيوم واالروديوم الثالثية الشحنة مع الليكاند معقداتحضرت ثنائي مثيل فينول. شخصت االمركبات المحضرة بوساطة -2،4نايتروانيلين مع -4فينول المشتقة من تفاعل ازدواج -آزو) ، ( (C.H.N)المرئية والتحليل الدقيق للعناصر -اء وفوق البنفسجيةأطياف الرنين النووي المغناطيسي، األشعة تحت الحمر فضال عن قياسات التوصيلية الكهربائية. درست تراكيب المعقدات باستعمال طريقتي النسب المولية والمتغيرات المستمرة، النتائج الطيفية ) ومنM 4-3×10 - 4-1×10بير ضمن مدى التراكيز ( –وخضعت محاليل هذه المعقدات لقانون المبرت فلز: ليكاند. ومن النتائج المحصول عليها تم اقتراح الشكل ثماني السطوح 3:1)والتحليلية وجد ان نسبة التفاعل هي ( .للمعقدات المحضرة المعقدات، العناصر اإلنتقالية، الدراسات الطيفية، اصباغ اآلزو. - :كلمات مفتاحيةال