Synthesis And Properties Of Phosphorus Multifunctional Ligands And Their Eu(Ⅲ)Complexes

In this study,four new phosphorus multifunctional ligands and their europium complexes have been synthesized and characterized by elemental analysis,IR,1HNMR,DSC and TGA.And the ligands were calculated by full-optimized molecular geometry with Gaussian 09 program.The consequence proved that the ligands form 1:1 complex with europium,separately.The interaction of complexes and bovine serum albumin(BSA)was analyzed by UV spectra and fluorescence spectrometry at different temperatures.From the study of the UV spectra we found that these four kinds of europium complexes with bovine serum albumin has a strong binding capacity,the size of its binding capacitiesy:Eu(pic)3L3>Eu(pic)3L2>Eu(pic)3L1>EuL4.The interaction of complexes and bovine serum albumin(BSA)was studied by fluorescence spectrometry at different temperatures.The results indicated that the complex caused the fluorescence quenching of BSA through a static quenching procedure.The binding constants K,the number of binding sites n,and corresponding thermodynamic parameters enthalpy change(ΔH>0),entropy change(AS>0),Gibbs free energy change(ΔG<0),between complex and BSA at different temperatures were calculated.The results showed that this reaction can be spontaneous(the G<0)and exothermic,The primary binding pattern between complex and BSA was interpreted as van der waals forces and hydrogen bonding interaction.The effects of metal ions Cu2+ and Fe3+on the interactions between BSA and complexes were investigated and the results indicated that there was a stronger binding force between complexes and BSA Under the Cu2+and Fe3+ mediated.The interaction modes of complexes and DNA were analyzed by UV spectra and fluorescence spectrometry.The results such as blue shift of absorption peaks and binding constants were calculated with similar reported,we hypothesized that the complexes can insert into the inner of DNA bi-helix structure.The interaction of complexes and DNA was studied by fluorescence spectrometry,the results indicated that the complexes caused the fluorescence quenching of DNA through a static quenching procedure,we hypothesized that there are intercalation interaction between calf thymus DNA and complexes.The antibacterial activity of rare earth complexes of against Escheichia coli and Stphylococcus aureus was investigated in inhibition zone,and the inhibition zone test prove that these complex have obvious inhibiting effects Escheichia coli and Staphylococcus aureus.