Журнал структурной химии №1 2008 (341,00 руб.)

Q. Xing1, X.D. Zhang1, and R. Xu1 1 Department of Chemistry, Liaoning University, Shenyang, 110036, Peoplecs Republic of China Department of Pharmacology, Liaoning University, Shenyang, 110036, Peoplecs Republic of China 2 Received 27 February, 2007 The two title coordination compounds, (NH4)3[TbIII(ttha)] 5H2O (ttha = triethylenetetramineN,N,Nc,Ns,Nccc,Nccc-hexaacetic acid) and (NH4)4[Tb III 2 (dtpa)2] 9H2O (dtpa = diethylenetriamine-N,N,Nc,Ns,Ns-pentaacetic acid), have been prepared and characterized by FT-IR, elemental analyses, TG-DTA and single crystal X-ray diffraction technique. <...> INTRODUCTION During the past several decades rare earth metal complexes have attracted significant research efforts due to their specific biological activities and potential applications [ 18 ]. <...> In particular, some TbIII complexes with aminopolycarboxylic acid ligands were adopted as the probes for proteins because of prominent luminescence traits [ 10, 11 ]. <...> Ttha (triethylenetetramine-N,N,Nc,Ns,Nccc,Nccc-hexaacetic acid residue) and dtpa (diethylenetriamine-N,N,Nc,Ns,Nspentaacetic acid residue) (see Scheme) are two key ligands among the aminopolycarboxylic acids. <...> They both tend to form complexes with 1:1 ratio with most rare earth metal cations. <...> After years of research work on the rare earth metal complexes with various aminopolycarboxylic acid ligands, the coordination numbers and configurations were found to follow certain principles [ 1215 ]. <...> In general, the rare earth metal cations can form eight-, nine- and ten-coordinate complexes with various aminopolycarboxylic acid ligands, since they have different ionic radii and electronic configurations. <...> Furthermore, rare earth metal complexes with ttha ligand tend to form structures different from the corresponding complexes formed with dtpa ligand, as demonstrated for their ammonium salts. <...> Rare earth metal cations having middle-size radii generally form nine-coordinate complexes with ttha ligand; these complexes have mononuclear molecular structure [ 1720 ]. <...> However, TmIII and LuIII cations form binuclear eight-coordinate complexes with the ttha ligand because of their smaller ionic radii and more f-electrons [ 21 ]. <...> On the other hand, currently known rare earth metal complexes with dtpa <...>