The Syntheses And Biological Properties Of Transition Complexes Assembled By Naphthalene-1,8-dicarboxylate Ligand

Metal coordination compounds are a very important research topic and have wideapplication prospects in molecular recognitions, magnetic, superconductor,asymmetric and heterogeneous catalysis etc. Among them,1,8-naphthalenedicarboxylate ligand is of particular interest to us, since its two carboxyl groups canbe completely or partially deprotonated to form multiple coordination sites, thusproviding a possibility to build variety of structures. The more important cause is thatthe large conjugated system of the rigid naphthalene ring in1,8-naphthalenedicarboxylate ligand may provide potential supramolecular recognition site for DNAby π-π aromatic stacking interactions.Much attention has been focused on the research of interaction between transitionmetal complexes and DNA. Such compounds are mainly two functions: Design andSynthesis of artificial nuclease, in order to achieve a specific shear on certain sites inthe DNA chain, and designed to excellent antineoplastic drug or antiviral agent. Theartificial nuclease is called chemical nuclease; it is a kind of tool used in cleaving theartificial synthesized DNA or RNA. Researches on chemical nucleases have importantmeanings in both theoretical and practical apply. The research contents of this thesisare as follows:1. Due to the good structure rigidity and thermo-stability of the aromaticcarboxylic acids. We select naphthalene-1,8-dicarboxylic acid as the main ligand,1,10-phen as auxiliary ligand. Under hydrothermal conditions, we synthesized fourtransition metal complexes as follows:[Ni(1,8-ndc)(1,10-phen)(H2O)2]611H2O (1)；[Co(1,8-ndc)(1,10-phen)(H2O)2]615.5H2O (2)；[Cd(1,8-ndc)(1,10-phen)(H2O)]22H2O(3)；[Cd(1,8-ndc)(1,10-phen)(H2O)]2(4).The results of the X-ray single-crystal strcuture analysis are as follows:1and2are a hexanuclear unit, and both are the two-dimensional structure constructed by twokinds of π-π interactions;3and4both are binuclear unit with analogous struture,3isa three-dimensional supramolecular network constructed by hydrogen bonds and π-πinteractions,4is a three-dimensional structure constructed by π-π interactions. The IR,elementary analysis of complexes has been studied. 2. Here we compared the interactions between DNA and four serial Mn(II)complexes assembled by naphthalene-1,8-dicarboxylate Ligand([Mn(1,8-ndc)(phen)2(H2O)] CH3OH H2O (5),[Mn(1,8-Hndc)(phen)2]22ClO44H2O(6)，[Mn(1,8-ndc)(phen)(H2O)2]2CH3OH H2O (7),[Mn(1,8-ndc)(phen)(H2O)2]611H2O (8)). All of the complexes can cleave plasmid DNA under physiologicalconditions (37°C, pH=7.4) in the presence of H2O2. CD and fluorescencespectroscopy indicate that the two complexes (complex5and6) have higherDNA-binding affinities than the other two (complex7and8). The agarose gelelectrophoresis studies show that complex7and8have faster DNA cleavage kineticsand lower activation energies than complex5and6.