A New Screw-Sense Switchable Polysilylene with Quantized and Superposed Helicities

Abstract
A new rod-like polysilylene bearing a β-branched alkyl group, poly[(S)-3,7-dimethyloctyl(2-ethylbutyl)silylene], was found to undergo a thermo-driven, helix–helix transition at −7 °C in isooctane associated with the discontinuous changes in the singlet σ–σ* excitation energy in the silicon backbone in the switching temperature region.