Optical Activity and Helicity Enhancement of Highly Sensitive Dinaphthylmethane-Based Stereodynamic Probes for Secondary Alcohols

Chirality transfer from circular
dichroism (CD)-silent secondary
alcohol (inductor) to the stereodynamic bichromophoric di­(1-naphthyl)­methane
probe (reporter) led to the generation of intense, induced exciton-type
Cotton effects (CEs) in the ultraviolet–visible absorption
region. The di­(1-naphthyl)­methane probe exhibits extraordinarily high
sensitivity to even small structural variations of the alcohol skeleton,
that is, the probe is able to distinguish between an oxygen atom and
a methylene group in a 3-hydroxytetrahydrofurane skeleton. Signs and
amplitudes of the exciton couplets of 1Bb electronic
transition might be correlated with the type of stereo-differentiating
parts of the molecule flanking the stereogenic center, however, not
with the absolute configuration. The origin of the induced CEs was
established by means of experimental and theoretical methods. As a
result, a mechanism of chirality transfer from the permanent stereogenic
center to the bichromophore is proposed.