Molecular Recognition of Aliphatic Diamines by 3,3′-Di(trifluoroacetyl)-1,1′-bi-2-naphthol

The
fluorescent responses of 3,3′-di­(trifluoroacetyl)-1,1′-bi-2-naphthol
toward a variety of amines have been studied. It was found that the
aliphatic primary 1,2- and 1,5-diamines can greatly enhance the fluorescence
of this compound, but under the same conditions, primary, secondary,
and tertiary monoamines cannot turn on the fluorescence of this compound.
In addition, this compound was shown to be an enantioselective and
diastereoselective fluorescent sensor for chiral diamines. UV absorption
and NMR spectroscopic methods have been used to study the interaction
of the sensor with amines. These studies have demonstrated that the
intramolecular OH···OC hydrogen bonding of
the sensor is important for both the reactivity of its trifluoroacetyl
group with the amines and its fluorescent responses. The interaction
of both of the two amine groups of a diamine molecule with the sensor
is essential for the observed fluorescent sensitivity and selectivity.