Browsing by Author "Tella, A. C."
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Item Coordination Polymer Based on Mixed Carboxylate Ligands: Synthesis and Thermal Studies(Faculty of Science, Ankara University, Turkey, 2018-09-10) Adimula, V. O.; Tella, A. C.; Udeaga, I. C.; Durodoye, A. T.; Lawal, A.The synthesis of Co(II), Cu(II), Fe(II) and Zn(II) based coordination compounds using terephthalic acid (BDC), tartaric acid (DHB), and 4hydroxybenzoic acid (4-HBA) as ligands by a solvent-based and solvent-free methods were reported. Thermal studies of the complexes performed in the temperature range of 30 ºC-950 °C showed a 9.406% weight loss observed between 200 ºC-517 ºC for [Co(DHB)(4-HBA)] complex, and a 1.883 % weight loss observed between 80 ºC352.68 ºC for [Cu(DHB)(4-HBA)] complexItem Solid- State Synthesis and Characterization of Cu (II) Complexes of 3,4,5- Trihydroxyl Benzoic acid(Faculty of Physical Sciences, University of Ilorin, Ilorin, Nigeria., 2017-11-30) Adimula, V. O.; Tella, A. C.; Lawal, A.; Shalme, N.Copper(II) complexes of 3,4,5-trihydroxybenzoic acid, formulated as [Cu(THB)(CH3COO)2] (1a and 1b), prepared by the solid state mechanochemical method (1a) of grinding Cu(CH3COO)2.H2O and 3,4,5trihydroxybenzoic acid in a mortar using a pestle in the absence of a solvent, and a solvent-based method of stirring in ethanol at room temperature (1b) is herein described. Characterization of the synthesized complexes was done by the methods of FT-IR and UV-Vis spectroscopy, PXRD analysis, elemental analysis, and melting point determination. Data obtained from the analytical and spectroscopic techniques indicated that the synthesized compounds, 1a and 1b, are identical. The Cu(II) ion was observed to coordinate to the ligand via the oxygen atom of two of the hydroxyl groups of the ligand resulting in the synthesized [Cu(THB)(CH3COO)2] complexes having a tetrahedral geometry with the ligand binding in a bidentate manner. The solid state mechanochemical synthesis technique offers a simple, quick and environmentally friendly route towards the preparation of metal complexes at the same time giving quantitative yield compared to the solvent-based method of synthesis.Item Solvent-free synthesis, x-ray studies and in vitro inhibitory activities of copper(II) complexes of non-steroidal anti-inflammatory drugs(Springer, 2014-04-10) Tella, A. C.; Obaleye, J. A.; Eke, U. B.; Isaac, A. Y.; Ameen, MubarakSolid-state mechanochemical synthesis of [Cu(CAF)2(H2O)(OAc)]OAc co mplex 1a and [Cu(COD)2(H2O)(OAc)]OAc complex 2a were obtained by grinding stoichioetric amounts of Cu(CH3COO)2 H2O and corresponding non steroidal anti-inflammatory drugs[(caffeine (CAF) and codeine(COD)], respectively, in a mortar with pestle. Solvent-based synthesis of 1b and 2b was also carried out by reaction of metal acetate salt and each drug by refluxing at 70 C in CH3OH for 1 h for comparison purposes. The complexes 1a and 2a were characterized by comparison of elemental analysis, FT-IR, UV–Vis and 1H NMR spectra with those of the free ligand and solvent-based products (1b and 2b). The analytical and spectroscopic data of the complexes prepared via the two different methods are almost identical. X-ray diffraction patterns of the complexes prepared by mechanochemical method were different from that of the starting material suggesting formation of new metal complexes. In vitro inhibitory activities of both mechanochemical and solvent-based complexes were found to be higher than parent ligands, indicating that the antimicrobial effect of these drugs could be enhanced when they are chelated to the metal. The mechanochemical synthesis was carried out without the use of solvent or external heating. The method is faster and gives a higher yield than corresponding solvent-based reactions. The solid state reaction presented higher efficiency in terms of materials, energy and time compared to solvent-based synthesis.Item Synthesis and characterization of new unsymmetrical bis-Schiff bases(Faculty of Science, University of Ilorin, 2018-07-10) Owalude, S. O.; AbdulRaheem, A.M.O.; Alemika, D.Y.; Tella, A. C.The literature is replete with symmetrical tetradentate bis-Schiff bases of 1,2-diamines with o-hydroxyaldehyde or ketones, but less attention has been focused on the analogous unsymmetrical tetradentate ones. Unsymmetrical Schiff bases of aromatic diamines are very difficult to obtain and are not easily isolated. This class of Schiff bases have very simple synthetic procedure and versatile coordination behavior. Metal complexes containing these Schiff bases in their structure usually possess exceptional antibacterial, antifungal and antitumor activities including anti-HIV activity. In this regard, two new unsymmetrical bis-Schiff bases, (Z)-N-(2-nitrophenyl)-N'-(2-((Z)-(2-oxoindolin-3-ylidene)amino)phenyl)acetimidamide (1) and (Z)-N-(2-nitrophenyl)-N'-((Z)-N-(2-oxoindolin-3-ylidene)carbamimidoyl)acetimidamide (2), were prepared from the condensation reactions of 2’-nitroacetanilide and 1H-indole-2,3-dione with o-phenylenediamine and guanidinium ions in ethanol. The corresponding symmetrical bis-Schiff bases (Z,Z)-1,3-bis(2-oxoindolin-3-ylidene)guanidine (3) and N-((2-(1-iminoethyl)-2-(2-nitrophenyl)hydrazinyl)methyl)-N-(2-nitrophenyl)acetimidamide (4) were also prepared. The data obtained from the elemental, IR and NMR spectroscopic analyses were used to propose structures for the four compounds.Item Synthesis and characterization of new unsymmetrical bis-Schiff bases(Faculty of Science, University of Ilorin, 2018-07-10) Owalude, S.O.; AbdulRaheem, A.M.O.; Alemika, D.Y.; Tella, A. C.The literature is replete with symmetrical tetradentate bis-Schiff bases of 1,2-diamines with o-hydroxyaldehyde or ketones, but less attention has been focused on the analogous unsymmetrical tetradentate ones. Unsymmetrical Schiff bases of aromatic diamines are very difficult to obtain and are not easily isolated. This class of Schiff bases have very simple synthetic procedure and versatile coordination behavior. Metal complexes containing these Schiff bases in their structure usually possess exceptional antibacterial, antifungal and antitumor activities including anti-HIV activity. In this regard, two new unsymmetrical bis-Schiff bases, (Z)-N-(2-nitrophenyl)-N'-(2-((Z)-(2-oxoindolin-3-ylidene)amino)phenyl)acetimidamide (1) and (Z)-N-(2-nitrophenyl)-N'-((Z)-N-(2-oxoindolin-3-ylidene)carbamimidoyl)acetimidamide (2), were prepared from the condensation reactions of 2’-nitroacetanilide and 1H-indole-2,3-dione with o-phenylenediamine and guanidinium ions in ethanol. The corresponding symmetrical bis-Schiff bases (Z,Z)-1,3-bis(2-oxoindolin-3-ylidene)guanidine (3) and N-((2-(1-iminoethyl)-2-(2-nitrophenyl)hydrazinyl)methyl)-N-(2-nitrophenyl)acetimidamide (4) were also prepared. The data obtained from the elemental, IR and NMR spectroscopic analyses were used to propose structures for the four compounds.Item Synthesis and structural characterization of some ruthenium(II) alkoxide complexes(Faculty of Physical Sciences, University of Ilorin, 2014-01-03) Owalude, S. O.; Odebunmi, E. O.; Eke, U. B.; Tella, A. C.The complex [RuCl2(COD)(OR)2] (COD = cyclo-octa-1,5-diene and R = CH3 or C2H5) has been prepared by treatment of the polymeric specie [{RuCl2(COD)}x]) with appropriate LiOR solution and has been characterized by elemental analysis, IR and lH NMR spectroscopic analyses. The reaction of the alkoxide complex with two or more equivalent of phosphine ligands gave the complex [Ru(COD)(OR)2L2] (R = CH3 or C2H5; L = methoxyphenyldiphenylphosphine and tri(m-tolyl)phosphine) while the subsequent reaction with diphenylphosphine yielded [Ru(OR)2(Ph2P)4] (R = C2H5). Spectroscopic and elemental analysis data revealed symmetric alkoxide bridged diruthenium phosphine complexes.