Dual Redox and Optical Control of Chiroptical Activity in Photochromic Dithienylethenes Decorated with Hexahelicene and Bis-Ethynyl-Ruthenium Units

We describe the synthesis of mono- and bis([6]helicene-equivalent to-Ru(dppe)(2)-equivalent to)-DTE complexes 1o,c and 2o,c. The photochromic and electrochromic properties were studied, and attractive isomerization processes were observed, i.e., spontaneous reopening of [lc](center dot+) to [1o](center dot+) and ring closure of [2o](2+) to [2c](2+). Due to strong chiroptical responses, all of these chiral complexes correspond to new types of chiroptical switches (triggered by light and/or redox stimuli) and could be described as either NOR or OR logic gates.