Materials capable of tunable optical absorption and fluorescence properties in response to multiple external stimuli,while providing a readable signal,have garnered significant scientific interest.Such materials hold ...Materials capable of tunable optical absorption and fluorescence properties in response to multiple external stimuli,while providing a readable signal,have garnered significant scientific interest.Such materials hold promise for applications in wearable electronics,anticounterfeiting technologies,self-powered light sources and displays,human-machine interfaces,and intelligent sensing systems.A highly effective approach to achieving multi-stimuli optical responsiveness is to integrate various functionalities into a single structure,such as reversible electrochemistry,ion and electronic charge transport,photoluminescence,and supramolecular organization(e.g.,mesomorphism).Here,we introduce a new class of thermotropic smectic ionic liquid crystals,composed of the bistriflimide salts ofπ-conjugated fluorenoviologen dications.The dications feature a central fluorene core functionalized in position 2,7 with two pyridine moieties,whose nitrogen atoms are alkylated with promesogenic alkyl chains of varying lengths.In their bulk liquid crystalline phases,these materials exhibit ON/OFF electrofluorochromism(under UV photoexcitation),with voltage-triggered fluorescence quenching and a shift from yellow to dark electrochromism.Additionally,they display thermofluorochromism,showing a striking fluorescence color change from green to blue on going from the crystalline solid phase at room temperature to the liquid crystalline phases at high temperatures.展开更多
基金the Ministero dell'Universita e della Ricerca Italiano(MUR)and the University of Calabria for supporting this project in the framework of the ex 60%budget grant.G.A.C.and A.B.acknowledge the financial support from MUR postdoctoral fellowship DM 737/2021-Grant b.(CUP H25F21001420001).
文摘Materials capable of tunable optical absorption and fluorescence properties in response to multiple external stimuli,while providing a readable signal,have garnered significant scientific interest.Such materials hold promise for applications in wearable electronics,anticounterfeiting technologies,self-powered light sources and displays,human-machine interfaces,and intelligent sensing systems.A highly effective approach to achieving multi-stimuli optical responsiveness is to integrate various functionalities into a single structure,such as reversible electrochemistry,ion and electronic charge transport,photoluminescence,and supramolecular organization(e.g.,mesomorphism).Here,we introduce a new class of thermotropic smectic ionic liquid crystals,composed of the bistriflimide salts ofπ-conjugated fluorenoviologen dications.The dications feature a central fluorene core functionalized in position 2,7 with two pyridine moieties,whose nitrogen atoms are alkylated with promesogenic alkyl chains of varying lengths.In their bulk liquid crystalline phases,these materials exhibit ON/OFF electrofluorochromism(under UV photoexcitation),with voltage-triggered fluorescence quenching and a shift from yellow to dark electrochromism.Additionally,they display thermofluorochromism,showing a striking fluorescence color change from green to blue on going from the crystalline solid phase at room temperature to the liquid crystalline phases at high temperatures.
