Insulated conjugated bimetallopolymer with sigmoidal response by dual self-controlling system as a biomimetic material
Hiroshi Masai, Takuya Yokoyama, Hiromichi V. Miyagishi, Maning Liu, Yasuhiro Tachibana, Tetsuaki Fujihara, Yasushi Tsuji, Jun Terao
Abstract
Biological systems are known to spontaneously adjust the functioning of neurotransmitters, ion channels, and the immune system, being promoted or regulated through allosteric effects or inhibitors, affording non-linear responses to external stimuli. Here we report that an insulated conjugated bimetallopolymer, in which Ru(II) and Pt(II) complexes are mutually connected with insulated conjugations, exhibits phosphorescence in response to CO gas. The net profile corresponds to a sigmoidal response with a dual self-controlling system, where drastic changes were exhibited at two threshold concentrations. The first threshold for activation of the system is triggered by the depolymerization of the non-radiative conjugated polymer to luminescent monomers, while the second one for regulation is triggered by the switch in the rate-determining step of the Ru complex. Such a molecular design with cooperative multiple transition metals would provide routes for the development of higher-ordered artificial molecular systems bearing bioinspired responses with autonomous modulation.