Responsive molecules: 1. Redox-responsive quadruple hydrogen bonding unit 2. Crosslinked dendronized polyols for brighter and more stable dyes 3. Photoresponsive proton gate for cross-membrane transfer

stimuli-responsive

Li, Ying

关键词: stimuli-responsive;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/90531/LI-DISSERTATION-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

This thesis reports studies in three separate contexts that show how responsiveness can be introduced or tuned in different molecular systems thus providing desirable control over material properties. In Chapter 2, we designed a new quadruple hydrogen-bonding module (eDAN). The binding affinity of this molecule towards its partner (DeUG) was specifically controlled by redox reactions without affecting other hydrogen-bonding recognition pairs in the system. This orthogonal switch was successfully applied to tune supramolecular polymer blends (Scheme 0.1). In Chapter 3, we developed a scalable and general synthetic approach to solubilize and stabilize different classes of organic fluorophores, which may be useful in bioimaging. The crosslinked dendronized polymeric structure obtained by ring opening metathesis polymerization and intra-molecular ring close metathesis reduced the responsiveness of dyes toward reactive excited species (Scheme 0.2).In Chapter 4, we designed the first synthetic photoresponsive proton gate incorporated in a lipid layer. The new proton carrier features a boronic acid head-group for proton transfer, a stiff stilbene body for photoresponsiveness, and an alkyl tail for lipid incorporation. The light-induced cross-membrane proton transfer was quantified by the activity of an O2 reduction catalyst buried under the lipid layer by electrochemistry. This molecular switch mimics the natural system allowing precise control of proton relocation without perturbing the proton thermodynamics (Scheme 0.3).