The Studies On Biological Activities Of Multi-topic Thioethers And Their Complexes

The coordination chemistry of N-containing heterocyclic ligands with AgI is oneof the main focuses in chemical research today. Fourteen of newphenyltetrazole-based multithioether ligands and eight of uracil-based multi-topicthioether derivatives have been prepared and characterized by IR and NMR spectra aswell as elemental analysis. Nine AgI complexes with the thioether ligands have beensynthesized. Crystal structural studies on these ligands and their AgI complexesrevealed that diverse structures from one-dimensional(1D) to three-dimensional (3D)have been constructed. The biological activity and fluorescence properties of selectedcomplexes and ligands were studied. The major contents are as follows.Phenyltetrazole-based multithioether ligands containing flexible linking unitsand their AgI complexes have been designed and synthesized. It was found that the Nand S atoms show equal coordination ability while space effect obviously affects thecoordination ability. In addition, the length of the linker and counter anions also showinfluence on the structure of the complexes and coordination modesPhenyltetrazole-based multithioether ligands containing rigid linker and their AgIcomplexes have been designed and synthesized. It is more difficult for the ligandscontaining rigid linker to form AgI complexes than those containing flexible ones, buttheir coordination manners are the same.Some tri-topic thioether ligands and their AgI complexes have also beensynthesized, in which the N atom in terazole ring has stronger coordination abilitythan the S atom does. It shows that the difference of the linkers has an importanteffect on coordination modes.The biological activity and fluorescence properties of Phenyltetrazole-basedmultithioether ligands have been studied. Most of the bi-topic samples present lowcytotoxin activety, whereas multi-topic phenyltetrazole derivatives containing triazineand trimethylenebenzene linkers show relatively higher biological activity. Thecharacteristic peak of the anion can be observed only in the IR spectrum of thecomplexes, but no difference could be observed in the UV and FL spectra between theligands and the complexes.The antitumour biological activities of Uracil-based multi-topic thioetherderivatives have been investigated. It was found that the derivatives containing rigidlinker have relatively higher biological activity, especially forα,α'-bi(2-uracilthioyl)-1,3-dimethylbenzene. Further works on the biological activitiesof these compounds are still in progress.