An Aryl-trans Poly(p-phenylenephosphaalkene)

Significance

An all-Z- (namely, aryl-trans) poly(p-phenylenephosphaalkene) (PPP) is synthesized by Becker reaction when the comonomer with a bulky aryl P-substituent (C₆Me₄) is utilized. This is a substantial progress since the first synthesis of PPP (an E/Z mixture) by the same research group (Angew. Chem. Int. Ed. 2002, 41, 2389-2392). The new Z-PPP, obviously an analogue of important poly(p-phenylenevinylene) (PPV), is shown to have fairly good π-conjugation although the bulky C₆Me₄ moieties make the backbone a little twisted. The conclusion is solidly drawn from the systematical investigation of the PPP and a series of model small molecules by UV/Vis spectroscopy and X-ray crystallography.