铜(II)-5-取代邻菲啰啉-二氧四胺大环三元体系的稳定性研究

The stability of copper (Ⅱ)-13-(2'-Hydroxy-3',5'-substituted benzyl)-1,4,8,11-tetraazacyclotetradecane-12, 14-dione(RTADO-14) binary complex compounds and of copper (Ⅱ)-5-substituted-1,10-phenanthrolines(R'TADO)-RTADO-14 ternary complex compounds was studied by means of pH titration method at 25.0±0.1 ℃ and I=0.1mol?dm-3KNO3. The formation constants of binary and ternary complexes were obtained. The structures of the binary and ternary complxes and the effects fo substituents on macrocyclic ligands and on R'Phen were also discussed.     

Study of kinetics and mechanism of the acid dissociation of copper(II) complex of novel C-functionalized macrocyclic dioxotetraamines

The kinetics of the acid dissociation of copper(II) complexes of novel C-functionalized macrocyclic dioxotetraamines has been studied by means of a stopped-flow spectrophotometer. The acid dissociation rate follows the law V_d = C_comkK₁K₂H ²/(1+K₁H+K₁K₂H ²). From the experimental facts we have obtained, the dissociation kinetics are interpreted by a mechanism involving the negatively charged carbonyl oxygen of the complex being rapidly protonated in a pre-equilibrium step, the rate-determining step being intramolecular hydrogen (enolic tautomer) migration (to imine nitrogen). The dissociation rate reached a plateau in the strongly acidic solution. By means of temperature coefficient method, ΔH ^φ, ΔS ^φ of the pre-equilibrium step and ΔH ^≠, ΔS^≠ of the rate-determining step were obtained. The results of 13-membered macrocyclic dioxotetraamines have been discussed. The influence of the substituents to the acid dissociation rates has also been discussed. The Bronsted type linear free energy relationships do also exist in these C-functionalized dioxotetraamine copper(II) complexes.     

Antibacterial activity of extract and fractions from branches of Protium spruceanum and cytotoxicity on fibroblasts

The crude ethanol extract (CEE) and fractions from branches of Protium spruceanum were subjected to antibacterial and cytotoxicity assays. Compounds of the most active fraction were identified by GC-MS and LC-MS. CEE was active against 19 bacteria and the ethyl acetate fraction (EAF) showed the lowest minimum bactericidal concentration (MBC 0.3–80.0 mg/mL). Through time-kill assay was observed that EAF induced rapid bactericidal effect against Staphylococcus saprophyticus. The cytotoxicity tests against L929 fibroblasts showed great potential of EAF on the treatment of infections caused by five bacteria (MBC < IC₅₀). The results provide in vitro scientific support to the possible application of branches of P. spruceanum as antimicrobial agent that may contribute for treatment of infections.     

铜(Ⅱ)-1，4，8，11-四氮杂环十四烷-12，14-二酮-α-氨基酸(5-取代邻菲咯啉)三元配合物的稳定性

本文采用pH法，在25.0±0.1℃, I=0.1 mol·dm^-3 KNO₃存在条件下，测定了铜(Ⅱ)-1，4，8，11-四氮杂环十四烷-12，14-二酮-α-氨基酸(5-取代邻菲咯啉)三元配合物的稳定常数，探讨了大环多胺配体与金属离子的配位能力、配位方式、及其在水溶液中铜(Ⅱ)配合物的稳定性，同时也研究了5-取代邻菲咯啉与铜(Ⅱ)之间的d-p反馈π键，取代基的Hammett诱导效应对三元配合物稳定性的影响。     

铜(Ⅱ)-5-取代邻菲啰啉-二氧四胺大环三元体系的稳定性研究

用pH法在25±0.1℃、I＝0．lmol·dm－3KNO3条件下研究了钢（Ⅱ）与13－（2’-羟基-3’、5’-取代苄基）－1，4，8，11-四氮杂环十四烷-12，14-二酮所形成的二元配合物的稳定性以及铜（Ⅱ）－5-取代-1，10-邻菲啉与13－（2’-羟基-3’，5’-取代苄基）－1，4，8，11-四氮杂环十四烷-12，14-二酮所形成的三元配合物的稳定性，并探讨了大环配体的取代基效应及二元、三元配合物的结构．