Abstract
9,9,10,10-tetraanisyl-9,10-dihydrophenanthrene exhibits unique electrochromic behavior with drastic change in color and structure accompanied by C-C bond fission to biphenyl-2,2'-diylbis(dianisylmethylium). By replacing the binaphthyl unit for the biphenyl skeleton, the configurationally stable chiral electron donors become available. Since only the neutral donors 1 exhibit strong fluorescence, the electrochemical input can further modify the fluorescent properties of the pair. Due to the configurational stability of helicity in 1 and axial chirality in 22+, the redox reaction of optically pure material undergoes stereospecifically, thus inducing chiroptical change such as circular dichroism (CD) as an additional output. Not only the UV-Vis but also the CD spectra of dications 22+ exhibit solvent dependency ("solvatochromism"), which endows the present system with a function of multi-input response system.
