Anion control of the formation of geometric isomers in a triple helical array.
The amide-substituted unsymmetrical ligand L(1) upon coordination to Co(2+) forms the dinuclear triple helicate [Co(2)(L(1))(3)](4+) which exists as both possible C(1) and C(3) symmetric geometric isomers in solution, however, upon addition of nitrate ions, the formation of an anion binding cavity is favoured and hence the sole product is the C(3) symmetric isomer in which all three amide substituents are hydrogen bonded to the nitrate anion.
Harding
Lindsay P
LP
Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield HD1 3DH, UK.
Jeffery
John C
JC
Riis-Johannessen
T
T
Rice
Craig R
CR
Zeng
Zuotao
Z