Tripod Structure Of Compounds And Their Transition Metal Complexes Synthesis And Characterization

In this thesis, four new tripodal compounds were synthesized. Their complexes with transition metals were prepared and characterized .The properties of these tripodal compounds for transporting alkali and alkaline earth metal ions across liquid membrane and extracting were studied and stability constants of their complexes were obtained through extraction. The results obtained showed that the good selectivity and transport abilities of tripodal ligands resulted from the good stabilities of their metal complexes. 1. Four new tripodal ligands L4-L7 and its complexes with transition metals were synthesized .The ligands and their metal complexes were characterized by elemental analysis, U IR, NMR and molar conductivity. The results obtained from element analysis, UV, LR, NMR and molar conductivity showed that the compositions of the complexes were as follows: For ligand L4, MLCLmnH2O (M= Fe3,m=3,n=2; MCo2,m2,n 1), M2LC14 (MCu2); For ligand L5, ML(NO3)X(MCd2,XzCH3OH,n=2 M=Ni , X=H20,n3); For ligand L6, ML (NO3) 2nH2O (MCo2, n4;M=Zn n=3), M3L2 (NO3) 23H2O (M=Cu2); For ligand L7, M3L2 (NO3) ?CH3OH (M=Cd2, Zn2), MLCl22CH3OH(MMn2). The bands of carbonyl or azacycle in IR were shifted upon complexing with transition metals. The biggest red shift of carbonyl bands in L4 and L7 was 72cm? Compared with this, the red shift of azacycle in ligand L5, L6 was smaller. The biggest shift was only lOcm?because of the weak complexing ability of azacycle. The infrared bands attributed to the nitrate groups in these complexes showed that the existence of uncoordinated nitrate groups. In UV spectra, the free ligands L4-L7 exhibited three strong bands at 200-280nm in methanol solution. When complexing with transition metals, the lower band(at about 255nm) had a red shift and the higher band(at about 275nm) had a blue shift. The shifts of ligands L4, L7 were greater than L5, L6 attributed to the good complexing abilities of them. The thermal decomposition properties of the complexes of four ligands were similar. At first, they lost crystallizing water or methanol and the final products were their corresponding metal oxides. The thermal decomposition was violent when the complexes were oxidized and decomposed and two or three exothermic peaks were produced. The thermal analysis showed that the stability of ligands was increased when they coordinated with metals. 2. The transport of alkali and alkaline earth metal ions across a liquid membrane using L1-L3, L4, L7 as ion carriers was studied. The results obtained revealed that ligands L1-L3 showed good transport abilities for Li+,Ca and the order of transport ability was L2>L1 >L3. The order of transport rate for L1-L3 was Li+>Ca2+>Na+>Ba2t>K >Mg . Ligands L1-L3 Li+/K+, K+ and 2+ and the order was showed good selectivity for Na+/ Ca2+/ Mg Ca2+/ Mg2+>Li+/K+>Na+/ K+. Ligands L4, + However, showed weak transport ability owing to the weak complexing abilities of them. 3. Through studies on the extraction of alkali and alkaline earth metal, we got the stability constants of complexes of ligands L1-L3 in chloroform. The results obtained revealed that the good transport ability and good selectivity of tripodal ligands resulted from the good stability of their metal complexes.