Practical Synthesis of Unsymmetrical Tetraarylethylenes and Their Application for the Preparation of [Triphenylethylene−Spacer−Triphenylethylene] Triads

We have demonstrated that reactions of diphenylmethyllithium with a variety of substituted benzophenones
produces corresponding tertiary alcohols that are easily dehydrated, without any need for purification, to
produce various unsymmetrical and symmetrical tetraarylethylenes in excellent yields. The simplicity of
the method allows for the preparation of a variety of ethylenic derivatives in multigram (10−50 g) quantities
with great ease. The methodology was successfully employed for the preparation of various triphenylethylene (TPE)-based triads (i.e., TPE−spacer−TPE) containing polyphenylene and fluoranyl-based
spacers. The ready availability of various substituted tetraarylethylenes allowed us to shed light on the
effect of substituents on the oxidation potentials (Eox) of various tetraarylethylenes. Moreover, the electronic
coupling among the triphenylethylene moieties in various TPE−spacer−TPE triads was briefly probed
by electrochemical and optical methods.