Molecular Recognition Properties of a Charge‐Transfer Host System Composed of 10,10′‐Dihydroxy‐9,9′‐biphenanthryl and Viologen Derivatives

Abstract A charge‐transfer (CT) complex composed of racemic rac ‐10,10′‐dihydroxy‐9,9′‐biphenanthryl as the electron‐donor and the diquaternary derivative of 4,4′‐bipyridinium (viologen) as the electron‐acceptor has been formed by the inclusion of guest molecules. The color and diffuse reflectance spectra of this inclusion CT complex are sensitive to the guest molecules, and their properties can be tuned by changing the component viologen derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)