An Effective Strategy to Tune Supramolecular Interaction via a Spiro-Bridged Spacer in Oligothiophene-<i>S</i>,<i>S</i>-dioxides and Their Anomalous Photoluminescent Behavior

We demonstrate that incorporating nonplanar spiro-bridged structures is an effective strategy for tuning supramolecular interactions of optoelectronic functional moieties. In the model compounds spiro-bridged oligothiophene-<i>S</i>,<i>S</i>-dioxides (BSiSDTFO), unusual dimers constructed by spiro-bridged spacers do not form excimers, which is confirmed by crystallographic data and fluorescent emission spectra.