Self-assembly lanthanides ligands

Lanthanides in Living Systems Lanthanides Coordination Chemistry Lanthanides Luminescence Applications Lmninescence Lanthanides Magnetic Resonance Imaging Lanthanide Oxide/Hydroxide Complexes Carboxylate Lanthanide Complexes with Multidentate Ligands Rare Earth Metal Cluster Complexes Supramolecular Chemistry from Sensors and Imaging Agents to Functional Mononuclear and Polynuclear Self-Assembly Lanthanide Complexes. 

Lanthanide Complexes with Multidentate Ligands Supramolecular Chemistry from Sensors and Imaging Agents to Functional Mononuclear and Polynuclear Self-Assembly Lanthanide Complexes. 

Although the self-assembly process is easy and convenient to operate, success in obtaining the expected object is still a challenge for chemists. The aims of this article are to summarize the coordination chemistry of amino acids, to review our recent work on 3d-4f heterometallic clusters bearing amino acid ligands, and to expound the effects of several factors of influence on self-assembly, such as presence of a secondary ligand, lanthanides, crystallization conditions, the ratio of Cu2+ to amino acids, and transition metal ions. We hope that our systematic researches on the 3d-4f amino acid clusters can provide a useful framework of reference for the study of other self-assembly systems. 

Triply bridged dinuclear Fe(n) complexes of a bis-N-hydroxy-pyridinone [9.82a] and of bis(bipy) ligands [9.61, 9.82b] possess triple-helical features. A triple-helical arrangement has been assigned to dinuclear Fe(lll) complexes of tripodal ligands on the basis of NMR and circular dichroism (CD) data [9.82c]. The self-assembly of well-defined triple-helical dinuclear cobalt(ll) [9.83] and lanthanide(lll) [9.84] complexes has been achieved. 

This last section deals with a few examples of the formation of self-assembly structures from lanthanide complexes, which are formed by using transition metal ions. This area of research is very novel and relatively few examples have been developed to date. While the lanthanide ions have been used to mediate the formation of supramolecular structures, such as helicates, many of which can have both/-/ mdf-d metal ions, etc. the focus here will be on the use of lanthanide complexes and ligand structures similar to those described above [170-173]. 

Compound 61 can be depicted in a cartoon manner as A in Scheme 6. Our idea was to form the linear f-d-f assembly (B) by simply using a Cu(II), Fe(II) or Zn(II) ion as the bridging unit where these would coordinate to the phen ligand and as such bring two of the lanthanide complexes together. While the formation of a self-assembly was successful, the desired structure (B in Scheme 6) was not exclusively formed. Using Cu(II) we showed that upon addition of 61, at pH 7.4, the Eu(III) emission was switched off. Moreover, the absorption spectra were shifted to the red and the singlet... 

Zheng, Z. (2001) Ligand-controlled self-assembly of polynuclear lanthanide-oxo/hydroxo complexes from synthetic serendipity to rational supramolecular design. Chemical Communications, (24), 2521-2529. 

FIGURE 44 Dltoplc bls-trldentate C2-symmetrical ligands used for the self-assembly of bimetallic lanthanide luminescent probes. 

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