Conjugated Polymers Featuring Oxacyclophane‐Scaffolded π‐Stacking Interactions

Abstract

An oxacyclophane framework is modifi ed to include π-conjugated segments positioned so as to allow an optimized face-to-face π-stacking interaction between them. This unique architecture is fi rst employed for the preparation of model compounds with defi ned interaction between two small molecular organic chromophores. The interaction allows facile through-space energy transfer between the chromophores when they are held in the appropriate geometry. The oxacyclophane is thus employed in a polymer with consecutive short stretches of phenylene ethynylene such that polymer chain conjugation requires through-space interaction between segments rather than the through-bond π-conjugation that typifi es traditional conjugated polymers. The extent of the through-space interactions along the polymer backbone is explored through photophysical measurements, calculations, X-ray diffraction, and comparison with a variety of model and control materials.

Conjugated polymers with regularly spacedm-phenylene units and post-polymerization modification to yield stimuli-responsive materials

“…Both small molecules (Chart (A)) and polymers (Chart (B)–(D)) have proven useful for fluorescence‐based detection of nitroaromatics . In each of these cases the bulky side chains such as iptycenes (Chart (A) and (B)), cyclophane‐containing ‘canopy’ (Chart (C)) and m ‐terphenyls (Chart (D)) provide free volume around a π ‐conjugated fluorophore for analyte occupancy. Crosslinked conjugated microporous polymer networks likewise provide the free volumes necessary for efficient nitroaromatic entry and detection …”

Synthesis of Molecular Wires Strapped by π-Conjugated Side Chains: Integration of Dehydrobenzo[20]annulene Units

“…In this study, we focused on the structure of [20]­DBAs as the cyclic π-conjugated side chain and synthesized π-conjugated-unit-strapped molecular wires incorporating the [20]­DBA moiety as a monomer unit and a canopy unit, which can undergo conversion under thermal conditions. To synthesize [20]­DBA-based π-conjugated polymer 2 by polymerization, we prepared the precursor of [20]­DBA monomer 1 , containing a tert- butyl group for increasing the solubility of the [20]­DBA unit and a diethyltriazene group for its conversion to iodide for further functionalization (Figure ).…”