Tunable SiN Hybrid Conjugated Materials

We report the synthesis
of a family of N-aryl cyclosilazanes. The
reaction of 1,2-bis­(trifluoro­methanesulfonate)­tetramethyl­disilane
with para-substituted anilines gives six-membered
rings with no observed condensation polymerization. X-ray crystallography
reveals the cyclosilazane adopts a twist boat conformation with both
nitrogens in a trigonal planar geometry. Solution phase UV–vis
spectroscopic studies coupled with density functional theory calculations
interrogate the ability of the nitrogen atom to bridge the σ-
and π-conjugated moieties. Depending on the aromatic substituent,
the cyclosilazane rings may be either more or less electron rich than
an all silicon ring.