Synthesis, characterization of mixed- ligand complexes containing 2,2

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Synthesis, characterization of mixed- ligand complexes containing 2,2-Bipyridine and 3aminopropyltriethoxysilane

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The Sixth Scientific Conference “Renewable Energy and its Applications” IOP Publishing IOP Conf. Series: Journal of Physics: Conf. Series 1032 (2018) 1234567890 ‘’“” 012066 doi:10.1088/1742-6596/1032/1/012066

Synthesis, characterization of mixed- ligand complexes containing 2,2-Bipyridine and 3-aminopropyltriethoxysilane Hayder Hamied Mihsen*, Nesser Kadham Shareef Department of Chemistry, College of Science, University of Kerbala, Kerbala, Iraq. Corresponding author’s E-mail: [email protected] Abstract. A mixed-ligand metal complexes with divalent ion Co, Ni and Cu containing 3aminopropyltriethoxysilane(3-APTES) as a primary ligand and 2,2-bipyridine as a secondary ligand were prepared. The new complexes were characterized by, Molar conductance measurement, magnetic susceptibility, Uv-visible spectra (Uv-Vis) ,infrared spectroscopy (FTIR), Nuclear magnetic resonance(1 H-NMR), Thermogravimetric analysis (TGA-DTA) and atomic absorption spectroscopy(ASS). FT-IR and 1 H-NMR spectra indicate that both ligands 3-APTES and 2,2-bipyridine are coordinated to the metal ions via nitrogen amino group in 3APTES and nitrogen atoms for bpy. Molar condu ctance value for the complexes indicate that the complex are non-electrolyte. The TGA-DTA analysis shows that the degradation of complexes occurs between 200-593 o C. The complexes assume octahedral geometry in which the Co(II),Ni(II),Cu(II) have two molecules of 3-APTES and one molecule from 2,2-bipyridine in the coordination sphere.

1. Introduction. 2,2-bipyridine is a compound where two pyridine rings are connected together, the bond between the pyridine rings in the α-position of the nitrogen[1]. 2,2-bipyridine is a chelating component it has been used as bridging ligand so it found different application in coordination chemistry. It form 5membered chelate ring which is stable upon coordination of metal. 2,2-bipyridine have widely used as a chelating donor site during such bridging ligand because its robust redox stability and relative ease of functionalization[2].Mixed ligand which contain 2,2bipyridine and other bidentate ligand are antineoplastic agents ,these compounds exhibit cytotoxicity, antitumor effect and genotoxicity also have been bactericidal, bacteriostatic toward many grampositive bacteria but they are ineffective against gram-negative organism[3-4]. Generally the organosilane is active at both end ,R is amino group(NH 2 ), mercapto (SH), or isocyanato (NCO).This functionality reacted with other functional groups in industrial or biomolecule for example peptides or oligonucleotides [5-7].While the other end consist of alkoxy silane. This functionality by hydrolysis converted to active group silanols. Which react with themselves to generated oligomeric. This silanol reacted with active surface that contain hydroxyl group. By regard ethoxy silane is less reactive than methoxy silane due to non-produce toxic ethanol while the other compound formed toxic methanol[8]. The reaction of the 3-Aminopropyltriethoxysilane (3-APTES) with transition metal ions must be performed in non-aqueous phase such as dry ethanol or dry benzene or hexane to avoid the hydrolysis of 3-APTES to ethanol and trisilanol [9-10]. 3-APTES can be used in the general reaction for synthesis functionalized ligands such as reaction of salicylaldehyde with 3-aminopropyltriethyoxysilane. The salicylaldimine ligands were reacted with either Cu(II) or Ni(II) salts to form both the model and functionalized Cu(II) and Ni(II) complexes [11]. The objective of the current study is to prepared the new mixed-ligand metal ion complexes; Co(II), Ni(II), Cu(II) containing 3-APTES as a primary ligand and 2,2-bipyridine as a secondary ligand . 2. Experimental part. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Published under licence by IOP Publishing Ltd 1


2.1. Materials and Sample characterization. All chemical material used were AR grade or of a high purity were used directly without further purification,3-aminoopropyltriethoxysilane (Sigma–Aldrich,,98%), 2,2-bipyridyl (BDH, 99%), Cobalt chloride hexahydrate(BDH, 99%), Nickel chloride hexahydrate (Fluka, 99%), Copper chloride dihydrate(BDH, 99%), ethyl acetate(Sigma–Aldrich,,99.8%), ethanol absolute (Fluka,99%), methanol (99%). The molar conductance measurements of the complex were measured in methanol at room temperature using[Digital conductivityMeter-WT-700-inolab]. The electronic spectra of solution of the complex and ligand in methanol solution(10-3 M)concentration were recorded in Uv-visible spectrophotometer-1800, shimadzu. FTIR spectra of the ligand and complexes were recorded using KBr pellets in shimadzu spectrophotometer. The 1 H-NMR spectra were recorded in DMSO-d6 solution using TMS as the internal standard in 500 MHz NMR spectrophotometer[Bruker Germany].Thermal analysis of sample were performed at heating rang(25-600o C) by using STAPT-1000LinseisGermany.Magnetic susceptibility measurements were measured using Auto magnetic susceptibility balance Sherwood scientific. Metal content of the complex were determined by atomic absorption technique using Japan A.A-67G Shimadzu. 2.2. Preparation of Complexes. To methanolic solution of CoCl2 .6H2 O or NiCl2 .6H2 O or CuCl2 .2H2 O (1 mmole), a solution of primary ligand 3-APTES (2 mmole) in 10 mL methanol was added drop wise with constant stirring. 1 mmole of bpy dissolved in the same solvent in (10 mL) was added, the mixture was reflexed for 4-6 hours. The formed precipitate was filtered and washed with cold absolute methanol several times and dried under oven. The reaction was monitoring by TLC using a mixture of ethanol : ethyl acetate (1:1) as an eluent. The data of metal analysis were obtained using flame atomic absorption technique. The calculated values are in a good agreement with the experimental values. Table(1) shows weights, yield% , metal analysis and some physical properties of prepared complexes. Table 1. Yield%, metal analysis and some of physical properties of prepared complexes. Compound Weight(gm) Weight(gm) Weight(gm) Yield% Color Melting Metal of metal of 3of Bpy in point analysis% salt in gm APTES gm oC (de) Cal.(Exp.) 0.5 0.9 0.3 70 Light320 8.08(8.70) [Co(3blue APTES)2(bpy)Cl2] [Ni(3APTES)2(bpy)Cl2]

0.5

0.9

0.3

55

Bluishgray

375

8.05(7.73)

[Cu(3APTES)2(bpy)Cl2]

0.5

1.3

0.46

62

Bluegreen

330

8.6(7.60)

3. Results and discussion. 3.1. FT-IR spectroscopy. Coordination of the cobalt(II),nickel(II),and copper(II) ions with functional groups of the mixed ligands 3-APTES and bpy are established in Table (2) and Figures (1-3).From the data spectra of the complexes. It can be seen that the bands of ʋ N-H in 3-APTES were shifted and changed in the shape due to coordination of amine group at the nitrogen atom with metal ions [12]. The absorption band of the (C=N)group in bpy appeared at(1454)cm-1[13].This band was shifted and changed in complexes to lower and higher frequencies because of coordinated with metal ions via the nitrogen atom[14].New

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bands appeared in the spectra of all metal complexes in the low frequency region between (300500)cm-1 ,those bands characteristic to M-N stretching vibrations[15]. Table 2. Characteristic FT-IR bands of the ligand and metal complexes. Frequency(cm-1) Compound C=Nʋ ʋNH2 ʋC=C ʋM-N 1454

bpy

1579 3369,,3298

3-APTES [Co(3-APTES)2(bpy)Cl2]

1514

3227,3417

1604

449

[Ni (3-APTES)2(bpy)Cl2]

1508

3273,3396

1600

459

[Cu(3-APTES)2(bpy)Cl2]

1444

3132,3227

1602

445

Figure 1. FT-IR spectrum of [Co(bpy)(APTES)2 Cl2 ].

Figure 2. FT-IR spectrum of[ Ni(bpy)(APTES)2 Cl2 ].

3


Figure 3. FT-IR spectrum of [Cu(bpy)2 (APTES)2 Cl2 ]. 3.2. Electronic spectra. Electronic spectra of the prepared complexes are recorded in warm methanol. The assignments for the electronic spectra are given in Table(3) . The electronic spectrum of Co(II) complex Fig.4 displayed one broad absorption band between (450-550)nm (22222-18181)cm-1 due to combination two transition ʋ3 4 T1 g→4 T2 g(P ) and ʋ2 4 T1 g→4 A2 g(f) respectively for octahedral geometry[16-18] . The spectrum of nickel(II) complex Fig.5 don’t show any d-d transitions ,while ligand metal charge transfer LMGT (Л(bipy)→dNi ) is appear as absorption band at higher intensity about 300nm(33333cm1 ) since obscure d-d transition , the shape may be is octahedral[17,19].The electronic spectrum of Cu(II) complex (not shown) give single broad absorption of high intensity(ϵ =200L -1 .M-1 .cm-1 ) is observed at 620nm (16129cm-1 ) which belong to 2 Eg→2 T2 g thus the shape may be distortion octahedral[20,21]. Table(3) also molar conductance of all the complexes. The values were showed that prepared complexes are non-electrolytic. Fig.6 shows general structure for prepared complexes. Table 3. Electronic spectral data for prepared complexes. Complex Band absorption Transition (cm-1 ) 22222-18181 4T1g(f)→4T1g(P) [Co(3-APTES)2(bpy)Cl2] 4T1g→4A2g(F)

Conductivity μs/cm 67

[Ni(3-APTES)2(bpy)Cl2]

33333

П(bipy)→dNi

32


16129

2Eg→2T2g

48

4


Figure 4. Uv-Vis spectrum for [Co(3-APTES)2 (bpy)Cl2 ].

Figure 5. Uv-Vis spectrum for [Ni(3-APTES)2 (bpy)Cl2 ].

Figure 6. Proposed structure of the complexes.

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3.3. 1 H-NMR spectroscopy. For the Co(II) complex in DMSO-d6 , the signals related to the 3-APTES protons appeared at 0.9150.990 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 –CH2 ), 1.017-1.095 ppm (18H,CH3 ) belong to –Si– OCH2 –CH3 ,1.118-1.272 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 –CH2 ), 2.448-2.521 ppm (4H,NH2 ) belong to (Si–CH2 –CH2 –CH2 -NH2 ), 3.303-3.337 ppm (4H,CH2 ) belong to Si–CH2 –CH2 –CH2 ), 3.4013.500 ppm (12H,CH2 ) belong to (–Si–OCH2 –CH3 ) [23,24], 7.22 -8.812 ppm belong to protons of bpy [3,25] . The 1 H-NMR spectrum of the Ni(II)complex, in DMSO-d6 , exhibited the signals related to 3APTES protons located at 0.259-0.401 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 –CH2 ), 1.017-1.230 ppm (18H,CH3 ) belong to –Si–OCH2 –CH3 , 1.633-1.752 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 – CH2 ), 2.467-2.631 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 –CH2 -NH2 ), 3.314-3.364 ppm (4H,CH2 ) belong to Si–CH2 –CH2 –CH2 ), 3.409-3.512 ppm (8H,CH2 ) belong to(–Si–OCH2 –CH3 ) [26,27], 7.24512.003 ppm belong to protons of bpy [3,25]. The 1 H-NMR spectrum of the Cu(II) complex in DMSO-d6 Figures. (7-8), show the signals related to 3-APTES protons appeared at 0.975-1.083 ppm (4H,CH2 ) belong to (Si–CH2 –CH2 –CH2 ),, 1.1231.694 ppm (18H,CH3 ) belong to –Si–OCH2 –CH3 , 2.054-2.137 ppm (4H,CH2 ) belong to (Si–CH2 – CH2 –CH2 ), 2.487-2.585 ppm (4H,NH2 ) belong to (Si–CH2 –CH2 –CH2 -NH2 ), 3.144-3.298 ppm (4H,CH2 ) belong to Si–CH2 –CH2 –CH2 ), 4.052-4.119 ppm (8H,CH2 ) belong to(–Si–OCH2 –CH3 ) [28,26], 7.101-11.623 ppm belong to protons of bpy[3,25].The peaks observed for all complexes illustrated the signals of amine group and other protons for 3-APTES and bpy are shifted and some it were changed intensity, this good evidence that complexes were formed[22].

Figure 7. 1 H-NMR spectrum of [Cu(3-APTES)2(bpy)2 Cl2 ].

Figure 8. 1 H-NMR spectrum of [Cu(3-APTES)2 (bpy)2 Cl2 ].

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3.4. Thermogravimetric analysis(TGA/DTA). Thermal analysis for many metal complexes was studied by TGA/DTA techniques through the rang (20-600 o C) at heating rate 10 o C/min under nitrogen atmosphere. The results of TGA/DTA are summarized in Table (4) and represented thermo grams is given in Figures (9,10 and 11). TGA curves refer to thermal stability of these complexes and decomposition steps ,in the first step the weight loss corresponding to the removal of molecules with low molecular weight such as water and ammonia which is demonstrated which agreement with IR analysis. While The second and third steps involved the thermal decomposition of the remaining parts of complexes [29,30].On the other hand DTA curves record the changes that causing by temperature such as melting, sublimation, vaporization or changes that attributed weight losses are represented an endothermic character [31,31] .While the processes crystallization or change in the crystal structure and oxidation are represented exothermic character[33].Generally many DTA curves for prepared complexes suggestion have a high thermal stability because the presence of 3-APTES as ligand in these complexes increase both the initial and final decomposition temperatures due to inherent high heat resistances of 3-APTES[34,35].

Figure 9. Thermogravimetric analysis(TGA/DTA)of [Co(3-APTES)2 (bpy)Cl2 ].

7


Figure 10. Thermogravimetric analysis (TGA/DTA)of [Ni(3-APTES)2 (bpy)Cl2 ].

Figure 11. Thermogravimetric analysis (TGA/DTA) of [Cu(3-APTES)2 (bpy)Cl2 ].

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Table 4. Thermo analytical result of prepared metal complexes. Compound

[Co(3APTES)2 (bp y)Cl2 ]

728

Weight loss% found 70.9

[Ni(3APTES)2 (bp y)Cl2 ]

728

4.85

4.6

20-194

2NH3

bpy,2Cl,2CH2 C H=CH2 Si2 (OCH2 CH3 )6 , Ni

12.4

12.6

194-400

2CH3 CH2 OH

byp,2Cl,2CH2 CH=CH2 2SiO2 ,CH3 CH2 ,2CH2 CH2 Ni

13.1

13.7

400-591

2Cl,CH3 CH2 -

byp,2CH2 CH=C H2 ,2SiO2 , CH3 CH2 ,2CH2 CH2 -,Ni

16.2

17.1

20-298

2NH3 ,2CH3 CH2 OH

2SiO2 ,byp,2CH2 CH2 CH= 2Cl,2CH3 CH2 ,2CH2 =CH2 Cu

47.9

46.4

298.2-591

2Cl,byp 2CH3 CH=CH2 CH3

2SiO2 ,2CH2 CH =CH2 Cu

[Cu(3APTES)2 (bp y)Cl2 ]

Molecular weight

733

Thermal rang

Compound decomposition

Compound product

Calc. 64.3

20-592

2NH3 ,2Cl,byp 2CH3 CH2 OH CH3 CH=CH-CH3 CH3 CH2 CH2 CH3

2SiO2 ,2CH2 CH2 CH= Co

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3.5. Magnetic susceptibility measurements of complexes. The magnetic moments Table (6). of complexes for cobalt(II),nickel(II) and copper(II) ions were 5.14, 3.9 and 1.92 B.M, respectively. This values are shown that the complexes have high spin momentum [36,37] . Table 5. magnetic properties of prepared complexes at 298 K. Complex

Xg×10-6

XM×10-6

D×10-6

XA×10-6

μeff B.M

[Co(3-APTES)2(bpy)Cl2]

14.8

10700

364.35

11060

5.14

[Ni(3-APTES)2(bpy)Cl2]

8.3

6046.7

364.2

6410.9

3.9


1.6

1170

366

1536

1.92

4. Conclusion. 3-APTES and 2,2-bipyridine was reacted with metal(II)(M=Co,Ni,Cu) to form mixed ligand complexes. 3-APTES act as monodentate ligand and 2,2-bipyridine act as bidentate and the coordinated with metal ions through the nitrogen atoms . Atomic absorption spectroscopy (ASS) technique was used to quantitative determination of metal in the complexes . The results showed that there is a great affinity between practical and theoretical percentages. Molar conductivity measurement show that the complexes was nonelectrolyte. Infrared spectroscopy, UV-Visible spectroscopy, 1 H-NMR spectroscopy were used to characterization the structure of the complexes that were produced. The TGA/DTA shows the complexes could be stable and it may decompose above 334°C. The evidence from the all spectroscopy showed the successful formation of these complexes. The proposed structures for prepared complexes with ions of Co(II), Ni(II) and Cu(II) are octahedral geometry.

Acknowledgments We would like to thank Kerbala University, Republic of Iraq for financial support. References [1] Peter J., 1990 “Aromatic nitrogen heterocycles as bridging ligands; a survey” Coordination Chemistry Reviews 106 227-265. [2] Selvaganapathy, M. and Raman, N., 2016 “Pharmacological Activity of a Few Transition Metal Complexes: A Short Review” Journal of Chemical Biology & Therapeutics. [3] Maurya R. C. , Patel, P. a & Rajpu,S.,2003 “Synthesis and characterization of Mixed‐Ligand Complexes of Cu(II), Ni(II), Co(II), Zn(II), Sm(III), and U(VI)O2, with a Schiff Base Derived from the Sulfa Drug Sulfamerazine and 2,2’-Bipyridine” Synthesis And Reactivity In Inorganic And Metal-Organic Chemistry 33( 5) 801–816. [4] Chandraleka, S., Ramya, K., Chandramohan, G., Dhanasekaran, D., Priyadharshini, A. and Panneerselvam, A., 2014 “Antimicrobial mechanism of copper (II) 1, 10-phenanthroline and 2, 2′-bipyridyl complex on bacterial and fungal pathogens” Journal of Saudi Chemical Society” 18(6) 953-962. [5] Schickle, K., Zurlinden, K., Bergmann, C., Lindner, M., Kirsten, A., Laub, M., Telle, R., Jennissen, H. and Fischer, H., 2011 “Synthesis of novel tricalcium phosphate-bioactive glass

10


[6] [7] [8] [9] [10] [11]

[12]

[13] [14] [15] [16] [17] [18] [19] [20] [21]

[22] [23] [24]

composite and functionalization with rhBMP-2.” Journal of Materials Science: Materials in Medicine 22(4) 763-771. Rovira-Bru, M., Giralt, F. and Cohen, Y., 2001 “Protein adsorption onto zirconia modified with terminally grafted polyvinylpyrrolidone” Journal of colloid and interface science 235(1) 7079. Huckel, M., Wirth, H.J. and Hearn, M.T., 1996 “Porous zirconia: a new support material for enzyme immobilization” Journal of biochemical and biophysical methods 31(3-4) 165-179. Witucki, G.L., 1993 “A silane primer: chemistry and applications of alkoxy silanes” Journal of coatings technology 65 57-57. Simon, A., Cohen-Bouhacina, T., Porté, M.C., Aimé, J.P. and Baquey, C., 2002 “Study of two grafting methods for obtaining a 3-aminopropyltriethoxysilane monolayer on silica surface.” Journal of colloid and interface science 251(2) 278-283. Malakooti, R., Bardajee, G.R., Hadizadeh, S., Atashin, H. and Khanjari, H., 2014 “An iron Schiff base complex loaded mesoporous silica nanoreactor as a catalyst for the synthesis of pyrazine-based heterocycles” Transition Metal Chemistry 39(1) 47-54. Murphy, E.F., Ferri, D., Baiker, A., Van Doorslaer, S. and Schweiger, A., 2003 “Novel routes to Cu (salicylaldimine) covalently bound to silica: combined pulse EPR and in situ attenuated total reflection-IR studies of the immobilization” Inorganic chemistry 42(8) 25592571. Fayad, N.K., Al-Noor, T.H., Mahmood, A.A. and Malih, I.K., 2013 “Synthesis, Characterization, and Antibacterial Studies of Mn (II), Fe (II), Co (II), Ni (II), Cu (II) and Cd (II) Mixed-Ligand Complexes Containing Amino Acid (L-Valine) And (1, 10phenanthroline)” Synthesis 3(5). Soliman, A.A. and Mohamed, G.G., 2004 “Study of the ternary complexes of copper with salicylidene-2-aminothiophenol and some amino acids in the solid state” Thermochimica Acta, 421(1) 151-159. Anupama, B. and Kumari, C.G., 2013 “Cobalt (II) complexes of ONO donor Schiff bases and N, N donor ligands: synthesis, characterization, antimicrobial and DNA binding study” International Journal of Research in Chemistry and Environment 3(2) 172-180. AL-Hashime, S.M., Sarhan, B.M. and Alazawi, S.A. “Synthesis and studies of som mixedligand metal complexes containing benzotriazol with some other ligands” transition 18 19. Figgis, B.N. and Lewis, J., 1960 “The Magneto Chemistry of Coordination polymer in Modern Coordination Chemistry”. Interscience, (New York). Shukla PR.(2012) “Advance Coordination Chemistry” Himalya publishing House, (Newdelhi) 165-204. Shirodkar, S.G., Mane, P.S. and Chondhekar, T.K., 2001 “Synthesis and fungitoxic studies of Mn (II), Co (II), Ni (II) and Cu (II) with some heterocyclic schiff base ligands”. Sutton, D., 1968 “Electronic spectra of transition metal complexes: an introductory text” (McGraw-Hill). Figgis, B.N., 1966. “Introduction to ligand fields”. Interscience Publishers. Lakshmi, P.A., Reddy, P.S. and Raju, V.J., 2009 “Synthesis, characterization and antimicrobial activity of 3d transition metal complexes of a biambidentate ligand containing quinoxaline moiety” Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 74(1) 5257. Shen, W.Z., Trötscher-Kaus, G. and Lippert, B., 2009 “1 H NMR spectroscopic identification of binding modes of 2, 2′-bipyridine ligands in complexes of square-planar d 8 metal ions” Dalton Transactions 39 8203-8214. Tataurova, Y., Sealy, M.J., Larsen, R.G. and Larsen, S.C., 2012 “Surface-selective solution NMR studies of functionalized zeolite nanoparticles” The journal of physical chemistry letters 3(3) 425-429. İspir, E., Kurtoğlu, M., Purtaş, F. and Serin, S., 2005 “Synthesis and Antimicrobial Activity of

11


[25] [26]

[27]

[28] [29] [30] [31]

[32] [33] [34] [35] [36] [37]

New Schiff Bases Having the–SiOR Group (R= CH 3or CH2CH3), and their Transition Metal Complexes” Transition metal chemistry 30(8) 1042-1047. Chandraleka, S. and Chandramohan, G., 2014 “Synthesis, characterization and thermal analysis of the copper (II) complexes with 2, 2-bipyridyl and 1, 10-phenanthroline” African Journal of Pure and Applied Chemistry 8(10) 162-175. Harmaraj, P., Kodimunthiri, D., Sheela, C.D. and Shanmuga Priya, C.S., 2009 “Synthesis, spectral characterization, and antimicrobial activity of copper (II), cobalt (II), and nickel (II) complexes of 3-formylchromoniminopropylsilatrane” Journal of Coordination Chemistry 62(13) 2220-2228. İspir, E., Kurtoğlu, M. and Toroğlu, S., 2006 “The d10 metal chelates derived from schiff base ligands having silane: synthesis, characterization, and antimicrobial studies of cadmium (II) and zinc (II) complexes” Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry 36(8) 627-631. Joubert, C., 2013 “Heterogenization of Schiff base complexes on mesoporous silica and their application as catalysts in the oxidative transformation of alcohols “(Doctoral dissertation, Stellenbosch: Stellenbosch University). Lippincott, E.R., Van Valkenburg, A., Weir, C.E. and Bunting, E.N., 1958 “Infrared studies on polymorphs of silicon dioxide and germanium dioxide” Journal of Research of the National Bureau of Standards 61(1) 61-70. Thana J.,A, Hayder H., M.,and Kasim M., H.,2017 “Catalytic esterification via silica immobilized p-phenylenediamine and dithiooxamide solid catalysts” Arabian Journal of Chemistry 10 S1492–S1500 Sarmento, V.H.V., Schiavetto, M.G., Hammer, P., Benedetti, A.V., Fugivara, C.S., Suegama, P.H., Pulcinelli, S.H. and Santilli, C.V., 2010 “Corrosion protection of stainless steel by polysiloxane hybrid coatings prepared using the sol–gel process” Surface and Coatings Technology 204(16) 2689-2701. Chang, T.C., Wang, Y.T., Hong, Y.S. and Chiu, Y.S., 2000 “Organic–inorganic hybrid materials. V. Dynamics and degradation of poly (methyl methacrylate) silica hybrids” Journal of Polymer Science Part A: Polymer Chemistry 38(11) 1972-1980. Laurén, T., 2007 “Methods and instruments for characterizing deposit buildup on heat exchangers in combustion plants” Licentiate thesis. Åbo Akademi, Faculty of Chemical Engineering, Process Chemistry Center. Roland, C.M., Kallitsis, J.K. and Gravalos, K.G., 1993 “Plateau modulus of epoxidized polybutadiene” Macromolecules 26(24) 6474-6476. Vadivel, M., Kumar, M.S.C., Selvam, V. and Alagar, M., 2012 “Studies on Thermal and Morphological Behavior of 3-Aminopropyltriethoxysilane Grafted Epoxidized EthylenePropylene-Diene Terpolymer”. Abdulghani, A.J. and Hussain, R.K., 2015 “Synthesis and Characterization of Schiff Base Metal Complexes Derived from Cefotaxime with 1H-indole-2, 3-dione (Isatin) and 4-N, Ndimethyl-aminobenzaldehyde” Open Journal of Inorganic Chemistry 5(04) 83. Sharma, A. and Shah, M., 2013 “Synthesis and characterization of some transition metal complexes derived from bidentate Schiff base ligand” Journal of Applied Chemistry 3 62-66.

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