Homochiral self-organization

Homochiral Metal-Organic Coordination Polymers for Heterogeneous Enantioselective Catalysis Self-Supporting Strategy... 

Cu(lOO), chiral Fe(TMA)4 clusters are formed. This is associated with the deprotonation of the carboxylic acid groups of TMA upon adsorption on the Cu substrate at temperatures above 250 K. Upon annealing at 400 K, homochiral porous network structures can be built up from these Fe(TMA)4 clusters in a hierarchical manner (Figure 6). The nanocavities of these networks have been used as hosts for the accommodation of Ceo and small biomolecules. The same group also investigated such important key factors for self-assembly as self-recognition, self-selection, self-repair, and dynamic self-organization for a library of linear dicarboxylates and bipyridines codeposited with Fe atoms onto a Cu(lOO) surface. ... 

As a different immobilization strategy for the heterogeneous asymmetric catalyst. Ding et cd. developed a self-supported polymer catalyst for the flow asymmetric reduction [140]. Self-assembly of chiral multitopic ligands and reactive metal ions afforded homochiral metal-organic coordination polymers, which exhibited... 

As such a method for catalyst heterogenization obviates the need of any extraneous supporting materials, the resulting homochiral metal-organic assemblies can be considered as self-supported catalysts [7, 48]. On the basis of this strategy, the chiral multitopic ligand can spontaneously form a chiral environment inside the cavities or on the surface of the soHds for enantioselective control of the reaction, and the metal ions act as the catalytically active centers. 

Lin and co-workers [177] have studied self-constructing arrays of individual Fe-l,2,4-benzenetricarboxyhc acid (Fe-tmla) complexes on a Cu(lll) substrate, produced by OMBE deposition of precursor tmla adlayers and iron atoms in ultrahigh vacuum. These selfconstructed metal-organic arrays (of four tmla molecules per one Fe atom) form large homochiral monolayers (i.e. both S and R chirality are found) extending laterally up to 200 nm. 

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