Synthesis of optically active through-space conjugated polymers consisting of planar chiral pseudo-meta-disubstituted [2.2]paracyclophane

The polymerization of enantiopure pseudo-meta-diethynyl[2.2]paracyclophane with a diiodobenzene derivative was carried out through Sonogashira-Hagihara cross-coupling. The synthesized polymers consisted of three-ring para-phenylene-ethynylene pi-electron systems that were stacked on each other at the terminal benzenes. The electrical photoconductivities of the pseudometa-linked and pseudo-para-linked polymers were examined. The corresponding optically active pseudo-meta-linked dimers were prepared, and their optical and chiroptical properties were compared with those of the pseudo-para- and pseudoortho-linked dimers. Optically active pseudo-meta-linked dimers and polymers emitted intense circularly polarized luminescence (CPL) with relatively high anisotropy factors on the order of 10(-3). The CPL behavior of the optically active pseudo-meta-linked dimer was simulated using time-dependent density functional theory calculations.

Automated summary

The synthesis of polymers with stacked three-ring para-phenylene-ethynylene pi-electron systems through Sonogashira-Hagihara cross-coupling was successful. The optically active pseudo-meta-linked dimers and polymers emitted intense circularly polarized luminescence (CPL) with relatively high anisotropy factors.