Abstract
Crowded triarylphosphine-quinone oligomers carrying phosphine moieties similar to tris(2,4,6-triisopropylphenyl)phosphine were synthesized by employing Suzuki coupling as a key reaction. 31P NMR spectra of the oligomers reflect distribution of the diastereomers arising from helicity of the propeller composed by three aromatic rings substituted on the phosphorus. UV-vis spectroscopy and cyclic voltammetry revealed that these crowded triarylphosphines carrying quinones, which display purple to blue color, exhibit corresponding charge-transfer absorption which blue-shifted as the difference between the oxidation potential of the phosphine moieties and the reduction potential of the quinone moieties becomes larger.
