Synthesis, characterization and DNA binding of the complexes of rare earth with phenanthroline and demethylcantharate

Three novel rare earth complexes, [Ln2(DCA)2(phen)2](NO3)2·6H2O (Ln(III)=Sm(III)(1), Er(III)(2), Yb(III)(3); DCA2-=de-methylcantharate, 7-oxabicyclo[2.2.1] heptane-2,3-dicarboxylate, C8H8O52-; phen=1,10-phenanthroline, C12H8N2) were synthesized. The structures were characterized by elemental analysis, molar conductance, IR and TGA. The results suggested that the structural features of the complexes were: in each DCA2-, one carboxylate group, as bidentate bridging group, connected two rare earth ions; the other carboxylate group, as bidentate chelate group took part in the coordination with rare earth ion. And cyclic ether oxygen of DCA2- and nitrogen atoms of phen took part in the coordination. The probable coordination number was seven. The interaction of the complexes with DNA was studied by UV-spectra, fluorescence spectra and viscosity measurements. Following increasing the concentration of DNA, the UV absorption bands nearby 265 nm of the three complexes appeared hypochromism and red-shift phenomena. And the values of binding constants Kb were 1.89×105 L/mol (1), 3.54×104 L/mol (2) and 3.83×104 L/mol (3). The complexes could quench the fluorescence of EB-DNA system, and the values of equilibrium constants Ksq were 1.72(1), 0.56(2) and 1.09(3). The relative viscosity of DNA steadily decreased with increasing the concentration of complexes. So, we could infer that the complexes may partially insert into DNA. The study of agarose gel electrophoresis showed that the complexes could cleave plasmid DNA, and the process of the reaction was through unclassical redox mechanism.     

Synthesis,crystal structures of novel complexes of rare earth with norfloxacin,interaction with DNA and BSA

Three novel rare earth complexes [N(CH 3) 4 ][Ln(NF) 4 ]·6H 2 O(Ln=Nd(III)(1),Sm(III)(2),Ho(III)(3)) were synthesized using hydrothermal method from norfloxacin HNF=1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid,C 16 H 18 FN 3 O 3),imidazole and rare earth nitrates.The complexes were characterized by elemental analysis,FT-IR,TG-DTG and X-ray single crystal diffraction.Each rare earth ion was eight-coordinated with carboxyl-O atoms and keto-O atoms from norfloxacin.Four of the norfloxacin ions acted as bidentate chelate group took part in the coordination with rare earth ion.The structures of complexes were tetragonal system with space group I4 1 /acd,which were allomerism.The interaction between complex 1 and DNA was studied by electronic absorption spectra and fluorescence spectroscopy.The binding interaction between the complex 1 and bovine serum albumin(BSA) was studied by fluorescence spectroscopy.The complex 1 bound to DNA by the mode of partial intercalation.Complex 1 had a strong ability to quench the fluorescence from BSA.The complex interaction was mainly a static quenching process with BSA together with formation of two binding sites.     

铝合金模板在超高层建筑中的应用与研究

近年来,随着城市人口的快速增长,人们对居住空间和环境的要求也越来越高。为了充分利用城市空间,超高层建筑应运而生。本文从建筑施工的角度,探讨铝合金模板施工技术及其在超高层建筑中的应用,总结铝合金模板在超高层建筑施工中的优势。