Redox-controlled selective docking in a [2]catenane host.
The docking by neutral and charged guests selectively in two geometrically different binding pockets in a dynamic [2]catenane host is demonstrated in the solid state by manipulating its redox chemistry. The change in redox properties, not only alters the affinity of the host toward neutral and charged guests, but it also induces a profound change in the geometry of the host to accommodate them. X-ray crystallography, performed on the two different 1:1 complexes, demonstrates unambiguously the fact that the [2]catenane host provides a uniquely different binding pocket wherein a methyl viologen dication is stabilized by interacting with a bipyridinium radical cation, despite the presence of Coulombic repulsions.
Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
Gokhan
G
Barin
Marco
M
Frasconi
Scott M
SM
Dyar
Julien
J
Iehl
Onur
O
Buyukcakir
Amy A
AA
Sarjeant
Raanan
R
Carmieli
Ali
A
Coskun
Michael R
MR
Wasielewski
J Fraser
JF
Stoddart