%0 Journal Article
%T Complexation of Oxovanadium(IV) and Dioxouranium(VI) with Synthesized 1,2-(Diimino-4¡ä-antipyrinyl)-1,2-diphenylethane Schiff Base: A Thermodynamic, Kinetic, and Bioactivity Investigation
%A Shabnum Bashir
%A Syed Raashid Maqsood
%A Ghulam Mustafa Peerzada
%A Badruddin Khan
%A Masood Ahmad Rizvi
%J Journal of Inorganic Chemistry
%D 2014
%R 10.1155/2014/268383
%X We report the comparative synthetic methodologies and characterization of a tetradentate Schiff base ligand 1,2-(diimino-4¡ä-antipyrinyl)-1,2-diphenylethane (DE). The target synthesis of oxovanadium(IV) and dioxouranium(VI) complexes (vanadyl and uranyl) with the (DE) ligand was also attempted to envisage the effect of metal ion steric factor on complexation process through solution phase thermodynamic and kinetic studies. The thermodynamic stabilities of synthesized vanadyl and uranyl (DE) complexes are discussed in light of their solution phase thermodynamic stability constants obtained by electroanalytical method. A comparative kinetic profile of vanadyl and uranyl complexation with DE is also reported. The complexation reaction proceeds with an overall 2nd order kinetics with both metal ions. Temperature dependent studies of rate constants present an activation energy barrier of ca. 40.913 and 48.661£¿KJ£¿mol£¿1, for vanadyl and uranyl complexation, respectively, highlighting the metal ion steric and ligand preorganization effects. The synthesized Schiff base ligand and its vanadyl and uranyl complexes were screened for biocidal potential as antibacterial, antifungal, and anthelmintic agents with the results compared to corresponding reference drugs. 1. Introduction Studies related to structure, reactivity, and applications of newly reported ligands and complexes form an imperative aspect of modern day inorganic chemistry. An insight into thermodynamic, kinetic, and biological property of compounds is always exciting and desirable from application point of view. Schiff bases are one of the most widely used organic compounds and their metal complexes have a variety of biological, analytical and material applications in addition to their important roles in catalysis and organic synthesis [1¨C6]. Schiff bases derived from the condensation of 4-aminoantipyrine with diketones represent an interesting class of biologically important chelating ligands; metal complexes of these ligands are of great interest owing to their pharmacological and analytical applications [7¨C11]. Conventional Schiff base synthesis makes use of high boiling, toxic organic solvent as reaction media for refluxing the amine and the aldehyde mixtures, followed by lengthy chromatographic workup of purification and recrystallization. In addition, to keep the equilibrium in the direction of forward reaction, the water is usually removed, either azeotropically by distillation or with a suitable drying agent [12¨C14]. Environmentally benign synthetic methods have received considerable attention
%U http://www.hindawi.com/journals/jic/2014/268383/