This facile interconversion of dinuclear double helicates and side-by-side species: a reprogrammable ligand with potential sensor applications

• Author

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5 The absorbance occurs ,350 nm, well within the ligand absorption
region. Addition of either Na+ or Ba2+ metal ions to 1 results in a decrease
in the absorption intensity in this region with the effect greatest for Ba2+.
The dark red colour observed is presumably due to MLCT to the p*
orbital of the planar bipyridine, which is usual for a Cu(I) system
coordinated by bipyridine ligand. Upon reprogramming of the ligand
strand the torsion angle of the bipyridine unit increases to 82u; with the
bipyridine unit no longer planar and acting as a mono-dentate ligand the
MLCT is quenched.
1982 | Chem. Commun., 2006, 1980–1982 This journal is The Royal Society of Chemistry 2006