Conformational and Optical Characteristics of Unidirectionally Twisted Binaphthyl-Bipyridyl Cyclic Dyads

An axially chiral
binaphthyl-bipyridyl cyclic dyad in which the
two units are connected by short −CH2O– linkers
was synthesized. Experimental and theoretical analyses indicate that
the (R)-binaphthyl unit in the dyad induces (R)-chirality in the bipyridyl unit, both in the solid state
and in solution. It is shown that vibrational circular dichroism (VCD)
is useful to determine the twisting pattern of 2,2′-bipyridyl
compounds. The dyad shows crystallization-induced emission enhancement
(CIEE).