\(Microsoft Word - \\332\\341\\355\\307\\301 \\332\\325\\307\\343\) Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. Spectral Study of Pt (II), Cr (II) Polymeric Complexes of the Ligand N- Crotonyl Department of Chemical Engineering / University Of Technology (Received 5 Abstract The polymeric complexes were obtained from the reaction of polymeric Schiff base.N hydroxyphenylazomethine (HL), with divalent metals complexes were determine through spectroscopic methods and compared with that reported from analogous monomeric ligand. This study revealed square planer geometry around the metal center fo geometry for Cr complex [Cr(L)Cl(H2O) Keywords: Schiff Base, Polymeric Complexes, Spectroscopic Methods, Divalent Metals 1. Introduction Polymer- metal complexes are composed of polymeric ligand and metal ions. They show unique characteristics in absorption spectrum, coordination structure, stability, redox reaction, catalytic activities, electro chemical reactions, and other areas, compared with those of corresponding low – molecular-weight metal complexes. Complexation of polymeric ligand with metal ions as well as the ligand substitution reaction of polymer –metal complexes is utilized to separate metal ions and/or small molecules Coordination polymers are usually known for their thermal stability [2].However, some other equally good application has been reported such as being used as converters of Solar energy and removal of SOx and NOx from the environment [18]. While (X= the number of Oxygen atom). Recently, an important new focus for environmental inorganic chemistry has been the selective removal of metal ions from aqueous solution, including waste treatment, with polymer supported chelate system [3]. Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) (II), Cr (II) Polymeric Complexes of the Ligand Crotonyl -2- Hydroxy-Phenylazomethine Alyaa Esam Mahdi Department of Chemical Engineering / University Of Technology Email:Esammustafa 73@yahoo.com (Received 5 September 2013; accepted 20 January 2014) The polymeric complexes were obtained from the reaction of polymeric Schiff base.N hydroxyphenylazomethine (HL), with divalent metals Pt (II), Cr (II). The modes of bonding and overall geometry of the complexes were determine through spectroscopic methods and compared with that reported from analogous monomeric revealed square planer geometry around the metal center for [Pt(L)Cl] and distorted octahedral O)2]. Polymeric Complexes, Spectroscopic Methods, Divalent Metals. metal complexes are composed of and metal ions. They show unique characteristics in absorption spectrum, coordination structure, stability, redox reaction, catalytic activities, electro chemical reactions, and other areas, compared with those of corresponding l complexes. Complexation of polymeric ligand with metal ions as well as the ligand substitution reaction of metal complexes is utilized to separate metal ions and/or small molecules [1]. Coordination polymers are usually known for .However, some other equally good application has been reported such energy and removal of SOx and NOx While (X= the number Recently, an important new focus for environmental inorganic chemistry has been the selective removal of metal ions from aqueous solution, including waste treatment, with polymer 2. Experimental All reagents were obtained commercially (Aldrich Company, UK) and use purification. Ethyl methyl ketone peroxide (EMKP) or 2, 2ˋ-azobisisobutyronitrile (AIBN) were used as initiator to prepare the ligand .IR spectra recorded as KBr or CsI discs using shimadzu 8300FTIR spectrophotometer in the rang 4000-250cm-1. Electronic spectra were measured in the region 200 solutions in DMF at 25O spectrophotometer. Conductivity measurements were made in DMF using a Jenway 4071 digital conductivity meter. 3. Preparation of the Complexes A mixture of the ligand HL (1mmol)in methanol (15ml) containing a few drops of HCL was added to a stirred solution of metal salt (1.1mmol) over 15 min using K complex, and CrCl3.6H2O for Cr complex in hot methanol (15ml) with 32% EMKP(1ml) in Al-Khwarizmi Engineering Journal (2013) (II), Cr (II) Polymeric Complexes of the Ligand Phenylazomethine Department of Chemical Engineering / University Of Technology The polymeric complexes were obtained from the reaction of polymeric Schiff base.N-crotonyl-2- Pt (II), Cr (II). The modes of bonding and overall geometry of the complexes were determine through spectroscopic methods and compared with that reported from analogous monomeric r [Pt(L)Cl] and distorted octahedral All reagents were obtained commercially (Aldrich Company, UK) and used without Ethyl methyl ketone peroxide azobisisobutyronitrile (AIBN) were used as initiator to prepare the ligand .IR spectra recorded as KBr or CsI discs using shimadzu 8300FTIR spectrophotometer in the Electronic spectra were measured in the region 200-900 nm using 10-3M OC using shimadzu 160 spectrophotometer. Conductivity measurements were made in DMF using a Jenway 4071 digital Preparation of the Complexes A mixture of the ligand HL (1mmol)in methanol (15ml) containing a few drops of HCL was added to a stirred solution of metal salt (1.1mmol) over 15 min using K2 PtCl4 for pt O for Cr complex in hot methanol (15ml) with 32% EMKP(1ml) in Alyaa Esam Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) 40 methanol (30ml) as the initiator. As shown in scheme (1). The resulting mixture was refluxed under N2 atmosphere for 3h, resulting in the formation of colored solution. The solution was concentrated by slow evaporation of the methanol at room temperature. The solid product formed was collected by filtration and washed with Ethanol (10ml) and finally with diethyl ether (15ml). The above procedure was used to give a dark brown solid for Pt2+ complex and yellowish green for Cr2+ complex. Scheme (1) Preparation of Cr, Pt Complexes. 4. Result and Discussion The reaction of salicylaldehyde with acrylamide afforded the new Schiff base N- crotonyl-2-hydroxy phenylazomethine HL in good yield. (scheme2) Scheme (2) Schiff Base HL. The IR spectrum for the ligand fig (1-A) shows a distinct band at 1666 cm-1 due toν(C=O).The spectrum also shows characteristic bands related to the, ν (C=N ) ,ν(C=C) and ν(O-H) functional groups (Table 1) [4,5].The U.V-Vis spectrum of HL fig (1-B)exhibits an intense absorption peak at 260 and 277 nm, which assigned to π → π∗, and an absorption peak at 325 nm assigned to n→ π∗ [Table 2]. The polymeric complexes were synthesized by heating 1mmole of Schiff base with 1.1 mmole of the metal chloride, in methanol using MEKP or AIBN as initiator and a few drops of concentrated HCL [17]. The two complexes [Cr(L)Cl (H2O)2] and [Pt(L)Cl] were obtained. The important infrared bands for the complexes together with their assignments are listed in [table 1]. The IR spectra of the complexes Figures (2, 3) exhibited HL bands with appropriate shifts due to complex formation [Table 1]. The two complexes show a strong band at (1628.9-1631.7) cm-1, assigned to a ν (C=N) stretch of reduced bond order [6].This can be attributed to delocalization of metal electron density (t2g) to the π system of the ligand. Theν (C=O) stretching band at 1666cm-1 in the free ligand is shifted to lower frequency and observed around (1668.3-1653) cm-1 for the complexes, indicating coordination of the oxygen of theν (C=O) group to the metal [7].In the IR spectrum of the pt(II)complex, theν (C=O) small shift of 2.3 cm-1on complexation could be attributed to the weak linkage between the oxygen atom and metal Centre . At lower frequency the complexes exhibit bands around (590 – 540) and (430-450) cm-1 which are assigned toν (M-O) and ν (M – N), respectively [15]. An additional band observed around 3398.3 cm-1in [Cr (L) Cl (H2O)2] is assigned to coordinated aqua (H2O) ligands [14]. The molar conductivity measurement for the complexes between 15 and 20 s.cm2mole-1 indicating their non-electrolytic behavior [8] and o oH N Alyaa Esam Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) 41 enhance that the chlor atom is inside the coordination ball [13] .The unit of conductivity is siemens=ohm-1 and the unit of molar conductivity is s.cm2mole-1. The IR spectra of the complexes exhibit far- IR active bands around (340-335) cm-1 which are assigned to the ν (M-CL) vibration. These vibrations are characteristic of terminally coordinated chloride [10-11]. The spectra of Pt (II) complex Fig (4) shows two bands (271-301) nm related to the ligand field [12] and a peak at 407 nm can be attributed to the1A1g 1B1g transition suggesting square planer structure [17]. The electronic spectra of the Cr(II) , complex Fig (5) exhibit a high intensity peak around 214 nm related to the charge transfer transition ,and 224 nm assigned to 1A1g→ 1B1g transition suggesting distorted Octahedral structure [12]. Table 1, Infrared Spectral Data (wave number�) ��� for Ligand and its Complexes. Table 2, Electronic Data of Ligand and its Metal Complexes. compound � � − �) ���� � � = �) � � = �) � �� = �) � � − �) � � = � − �) � � − �) � � − ��) Ligand HL 2750 1625 1666 700 - - - - ��� �)��� 2390 1628.9 1668.3 746.4 430 682.8 590 340 ��� �)�� ���)� � 2335 1631.7 1653 750 450 592 540 355 compound !� � " # �$ !%�&$���� '()* �+� �� ��� Assignment Ligand HL 260 38461 1500 π → π∗ 277 36101 2039 - → - ∗ 325 30769 72 . → - ∗ ��� �)�� ���)�� 214 46728 414 Charge transfere 224 44642 336 ′012 → 31 2 ��� �)��� 271 36900 1940 Ligand field 301 33222 1431 Ligand field 407 24570 611 ′012 → 312 Alyaa Esam Fig. 1 Fig. 1 Fig. 2 Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 42 1-A. Infrared Spectrum of the Ligand (HL). -B. Electronic Spectrum of the Ligand (HL). 2. Infrared Spectrum of � �� �)��� Complex. ng Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) Alyaa Esam Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) 43 Fig. 3. Infrared Spectrum of ��� �)�� ���)�� Complex. Fig. 4. Electronic Spectrum of� �� �)��� Complex. Fig. 5. Electronic Spectrum of ��� �)�� ���)��Complex. Alyaa Esam Al-Khwarizmi Engineering Journal, Vol. 9, No. 4, P.P. 39- 45 (2013) 44 5. Conclusion In the present work the synthesis and spectral study of coordination complexes from polymer of the Schiff base HL have been explored. In these complexes, the metal center is still able to adjust its preferred geometry which involves (C=O) coordination via its oxygen atom. Depending on spectral study of UV and IR spectrum and conductivity measurement, the proposed structure of the complexes were expected as follow: square planer for [Pt(L)Cl] and distorted octahedral for [Cr(L)Cl(H2O)2]. 6. References [1] Sushmita M. Roy,H.D.Juneja,and K.N Munshi syn.React.Inorg.Met.- org.chem,31(9),1611-1621 (2001). [2] ADEL ZEL-Sonbati,Ashraf A EL-Bindary and Naglaa A-EL-Deeb Designed monomers and polymers vol 4, No. 4, PP 357-367 (2001) [3] Mohammed Jaber Al-Jeboori,Ahmed T. Numan , Journal Ibn AL-Haitham pure & Applied Sciences 21. 89 (2008). [4] Nyquist RA Spectrochim Acta 23 A: 1635 0584-8539 (73) 80113-8. (1973) [5] Silverstein RM,Bassler GG Morril Tc spectrometric identification of organic compound 4th edn. Wiely New York. (1981) [6] Pinchas S, BenIshai D Amer chem. Soc 79:4099 DOI: 10.102/JA 01572a 35. (1957) [7] I.B.Liss.Feand E.O Schlemper Inorg chem., 14, 303, (1975). [8] EL-Sonbati AZ ,Elbindary AA new polym Mater 5:51(1996) [9] Nakomoto N, Infrared sepectra of inorganic and coordination compounds,vol 4. Wiley,New York. (1996) [10] Ahsen v, GÖK F ,BekarogluÖ, J chem. Soc, Dalton Trans 1827 .doi 10. 1039/dt987000 1827. (1987) [11] Lever ABP Inorganic Electronic spectroscopy vol 2. Elesvier publishing New York. (1984) [12] EL-Sonbati AZ, EL-Bindary AA, Diab MA, Spectro himic aActa part A:443,doi 10.1016/S1386 -1425 (02)00222-6. (2003) [13] Belghoul B Welterlich ,W,MaierA,T,outianoush A, Rabindranath A, Rabindrinath AR,Tieke B, Langmuir 23:5062. (2007) [14] Seddique M. Ahmed, Mohamed M. Shahata and Mostafa M. Kamal Journal of inorganic and organometalic polymers, vol. 13, No 3, Sep. (2003). [15] A.A El-BINDARI, A. S. Al-SHIHRI and A.Z. El-SONBATI Designed monomers and polymers. Vol 6, No. 3, PP 283-298 (2003). [16] S.M.Ropy,H.D.Juneja,K.N.Munshi.Synth.R eact.Inorg.Met-org.Chem,31(9),1611- 1621(2001). [17] A.A.EL-Bindary,A.S. AL- Shihri,A.Z.ELSonbati,Designed Monomers and polymers,6,3,283-298(2003). [18] Toshima,N.Removal of Harmful Gases by polymer Complexes ,Kogya Zairyo,39,45(1991). )2013( 39- 45، صفحة 4، العدد9مجلة الخوارزمي الھندسية المجلد علياء عصام مھدي 45 Cr (II) لليكند , Pt (II), الدراسة الطيفية للمعقدات البوليميرية لكل من N- Crotonyl -2- Hydroxy-phenylazomethine مھدي علياء عصام الجامعة التكنولوجية/ قسم الھندسة الكيمياوية yahoo.comEsammustafa@73 :البريد ا�لكتروني الخ)صة N- Crotonyl -2- Hydroxy-phenylazomethin بلمرلليكند المت )قاعدة شيف(يمكن الحصول على المعقدات البوليميرية عن طريق تفاعل [HL]. نوع التأصر والشكل الھندسي الكلي للمعقدات يمكن الحصول عليه عن طريق الدراسات الطيفية ومقارنتھا بالنسبة للمعقد . مع عناصر ثنائية التكافؤ واما بالنسبة لمعقد الكروم . ھو مربع مستوي [Pt(L)Cl] ھذه الدراسات أظھرت ان الشكل الفراغي لمركز العنصر بالنسبة لمعقد االبBتين) ا�صلي(ا�حادي [Cr(L)Cl(H2O)2] فقد كان ثماني السطوح مشوه.