Ruthenium-vinylhelicenes: remote metal-based enhancement and redox switching of the chiroptical properties of a helicene core

J Am Chem Soc. 2012 Sep 26;134(38):15628-31. doi: 10.1021/ja304424t. Epub 2012 Jun 25.

Abstract

Introducing metal-vinyl ruthenium moieties onto [6]helicene results in a significant enhancement of the chiroptical properties due to strong metal-ligand electronic interactions. The electro-active Ru centers allow the achievement of the first purely helicene-based redox-triggered chiroptical switches. A combination of electrochemical, spectroscopic, and theoretical techniques reveals that the helicene moiety is a noninnocent ligand bearing a significant spin density.