Systematic investigation of PPV analogue oligomers incorporating low-coordinate phosphorus centres

Sterically-encumbered ligands tethered to conjugated segments have been developed and employed in concert with existing bulky ligands to prepare a series of phospha-PPV oligomers. A study of the variation of lambda(pi-pi). values along this series indicates that low-coordinate phosphorus centres can support conjugation across extended systems, and generally confirms the expected red shift across the series from all-carbon oligomers to phosphaalkenes to diphosphenes. These findings provide experimental evidence that low-coordinate phosphorus centres are in fact capable of supporting electronic communication across extended pi conjugated systems. (C) Wiley-VCH Verlag GmbH Co.