Abstract
AbstractPolyalkyl-1,4,8,11-tetraazacyclotetradecanes have been synthesized by following the method of the direct organic condensation reaction or the techniques of metal template effect. These macrocyclic tetramines, including [H2(C-meso-5,6,12,13-Me4[14]dieneN4)] 2+(abbreviated as [ H2(Me4[14]dieneN4 A)] 2+ ) ，[H2 (C-racmic-5,6,12,13-Me4[14] diene N4 )] 2+ (abbreviated as [ H2(Me4[14]N4diene B)] 2+)，[H2{(5SR,6RS,12RS, 13SR)-5,6, 12, 13-Me4cyclam B}] 2+ (abbreviated as [ H2(C-meso-Me4cyclamB)] 2+ ) and [H2{(5RS,6RS, 12SR,13SR)-5,6,12,13-Me4cyclam A}] 2+ (abbreviated as H2 (C-meso-Me4cyclam A)] 2+ ), were subjected to react with copper(II) ion to form C-and N-disteroisomeric complexes which were separated. The crystal structures of the same of raese copper(II) complexes have been studies..Complexation reactions of copper(II) complexes with monodentate ligands have been studied in aqueous solution by spectrophotometric method. Using Cu(Me4[14]dieneN4 A)] 2+, [Cu(Me4[14]N4diene B)] 2+, [Cu(C-meso-Me4cyclamB)] 2+ and [Cu(C-meso-Me4cyclam A)] 2+, we determined their equilibrium constants which are different from each other. These constants can be quantitatively correlated by Edward’s equation, log(Kx / K0) = αEn +βH, where En is a redox factor and H is a proton basicity factor of the anionic ligands. The values of α,βandα/β for the copper(II) macrocyclic tetraamine complexes are reported and the factors which influence these values are also discussed.The dissociation kinetics in strongly acid medium for the above four copper(II) macrocyclic complexes have been investigated by spectrophotometric method in 0.1-5.0 M HNO3 at 25.0±0.1℃. This process was not found to occur by a single stage but to take place in consecutive-reversible steps. The kinetic scheme that can accommodate our observations is given in the following equation.Here B is an intermediate, and k1, k-1 and k2 are first-order or pseudo-first-order rate constants. The possible mechanism for the cleavage of copper-nitrogen bond to the rate were proposed by both, the directly protonation and the solvent associated pathways.These macrocyclic tetramines were allowed to react with cobalt(III) ion to form trans-dichloro-disteroisomeric complexs which were then isolated. Kinetic studies on the aquation of trans-[CoLCl2]+ complexes were followed spectrophotometrically method at m = 0.1M (NaNO3+ HNO3), and these results show large variation in rates among them. And we try to determine of transition state with Eying equation from rate values of different temperature.Reactions of these new macrocyclic tetramines with nickel (II) ion salts were led to the formation of trans-III-disteroisomeric complexs which were also isolated. These complexes exist in aqueous solution as an equilibrium mixture of both a blue, octahedral, high-spin species and a yellow, planar, low-spin species according to the below equation.The reaction in the above equation is endothermic and shifted to right by either an increase in temperature or by an increase of the concentration of inert salt. To determine the equilibrium constant of the reaction in equation with spectrophotometrically method at m = 0.1M (NaClO4), we investigate their thermodynamic parameters to discuss the factors which affect the equilibrium of this reaction. And we determined △H0 and △S0 values of these reactions. from constant values of different temperatures.