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Helicate, Macrocycle, or Catenate: Dynamic Topological Control over Subcomponent Self‐Assembly
Author(s) -
Hutin Marie,
Schalley Christoph A.,
Bernardinelli Gérald,
Nitschke Jonathan R.
Publication year - 2006
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200501591
Subject(s) - diamine , imine , chemistry , protonation , yield (engineering) , topology (electrical circuits) , phenylene , stereochemistry , polymer chemistry , medicinal chemistry , organic chemistry , materials science , catalysis , polymer , mathematics , ion , combinatorics , metallurgy
The aqueous reaction between equimolar amounts of 2‐(2‐(2‐aminoethoxy)ethoxy)ethanamine, 1,10‐phenanthroline‐2,9‐dialdehyde and copper( I ) produced a dimeric helical macrocycle in quantitative yield. This ring could also be generated by the addition of two equivalents of the diamine to an acyclic helicate containing four mono‐imine residues: A transimination occurred, the chelate effect being implicated as a driving force. In the case of a helicate containing mono‐imines derived from anilines, the substitution of diamine for monoamine was reversible upon lowering the pH. The aliphatic diamine was protonated at a higher pH than the arylamine, which left the arylamine free for incorporation instead of the alkyl diamine. This reaction thus opened the possibility of switching between closed macrocyclic and open helicate topologies by changing the pH. An additional closed topology became accessible through the use of a diamine that incorporates two rigid phenylene spacer groups between a flexible chain and the imine‐forming nitrogen atoms. The resulting catenate consists of a pair of topologically interlinked macrocycles. The presence of the phenylene groups appeared to dictate the topology of the final product, making the formation of a single macrocycle energetically disfavoured.