Self-assembly of helicates

Percec, V. et al. Principles of self-assembly of helical pores from dendritic dipeptides, Proc. Natl. Acad. Set USA., 103, 2518, 2006. 

Much work by Lehn et al. has been dedicated to the self-assembly of helical coordination complexes. Recently, ligand 59 has been shown to self-assemble with five iron(II) ions to form an intricate circular double helicate of 10" charge which surrounds and encapsulates a chloride ion. This chloride ion seemingly cannot be exchanged for larger ions as the inner core of the helicate = 1.75 A) is nearly... 

The self-assembly of helicates is a relatively complex process (see Section 3.3), even for homometallic binuclear 4f-4f species. Introducing dissymmetry both in the receptor ligand and in the nature of the metal... 

Kuo S-W, Lee H-F, Huang W-J, Jeong K-U, Chang F-C (2009) Solid state and solution self-assembly of helical polypeptides tethered to polyhedral oligomeric silsesquioxanes. Macromolecules 42 1619-1626... 

Figure 7 Hierarchical self-assembly of helical superstructures 3-4 in water. Electron micrographs of 4(a), 3(b),...

SCHEME 2.1 Self-assembly of triple stranded dinuclear helicate from three linear ligand strands and two metal ions (top). Hierarchical self-assembly of helicates by initial formation of mononuclear complexes followed by metal coordination of two units to several bridging metal ions (bottom). 

These observations indicate that the principle of hierarchical self-assembly of helicates is applicable not only to octahedral trischelate complexes. The reaction is more versatile and can generate new compounds with interesting physical (B fluorescence) or structural (M0O2) features... 

The self-recognition observed in the self-assembly of helicates of different lengths indicates that the structural instructions are sufficiently strong [10], whereas this is not the case when there are only small differences in ligand structure so that mixed-ligand helicates are formed [11]. It may be noted that robustness is a key feature in the behavior of biochemical networks [12]. A basic factor in self-recognition is commensurability of the components. 

Percec V, Dulcey AE, Peterca M, Hies M, Nummelin S, Sienkowska Ml, Heiney PA (2006) Principles of self-assembly of helical pores from dcaidritic dipeptides. Proc Natl Acad Sci USA 103(8) 2518-2523. doi 10.1073/pnas.0509676103... 

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