Speaker
Ms
Stephanie Boer
(Monash University)
Description
A series of quadruple-stranded Cu4L4 cages have been synthesised using ligands containing a biphenylsulfonediimide core substituted with two amino acid groups. Analogous chiral complexes (helicates) and achiral complexes (mesocates) can be formed by controlling or removing the stereocentres within the ligands.
Helicates, complexes which have supramolecular chirality generated by a helical sense within the complex, are formed using leucine-substituted ligands. These quadruple stranded Cu4L4 helicates contain copper paddlewheels at either end with the four ligands twisting between the Cu2 units. Changing the isomer of the amino acid changes the handedness of the helicate, with L-leucine forming the Λ helicate and the D-leucine forming the Δ helicate. The helicate cages are also shown to be self-selecting, as the reaction of a mixture of L-leucine and D-leucine substituted ligands forms the Δ and Λ cages with no product containing both ligands.
The chirality of the helicates can be disrupted by two different methods, to form a mesocate which lacks helical chirality. When the achiral glycine-derived ligand is used a quadruple stranded mesocate is formed (analogous to the chiral Cu4L4 cages) in which the ligands run straight ‘up-and-down’ the complex rather than in a helical manner. When a racemic DL-leucine-substituted ligand is used a similar mesocate is formed.
| Keywords | Homochiral Supramolecular Helicate Mesocate Cage |
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Primary author
Ms
Stephanie Boer
(Monash University)
Co-author
Dr
David Turner
(Monash University)
