| Summary: | 博士 === 國立交通大學 === 材料科學與工程學系所 === 102 === I
Abstract
Synthesis of Naphthalimide Derivative and Diketopyrrolopyrrole (DPP)-Based [2]Rotaxane/Polyrotaxane as Novel Chemosensor Materials and a Controllable Hierarchical Nano Self-Assembled Structure from Polyrotaxane
Student: M. V. P. S. K. R. Raju Advisor: Hong-Cheu, Lin
The pivotal objective of this dissertation is to construct novel orthogonally H-bonded mechanically interlocked molecular/polyrotaxane architectures with an asymmetric (Diketopyrrolopyrrole) stopper and to study their molecular shuttling process under solvent, anion, and acid-base stimuli control along with their controllable hierarchical nanostructure formations plugged with positive cooperativity non-covalent interactions. In the introduction of this doctoral thesis we have introduced
brief early synthetic attempts to create mechanically interlocked molecules (MIMs) such as rotaxanes and catenanes as well as their polymeric counterparts. Moreover novel templating methodologies to build MIMs and some latest examples of MIMs based molecular shuttles under various stimuli control were also introduced. Fundamentally, underplayed chemo sensing mechanisms in these systems were presented. Meanwhile, we have developed a novel and facile fluorescent ratiometric chemodosimeter for grisly toxic hydrazine via mild Ing-Manske phthalimide deprotection method in this doctoral thesis as well.
In chapter two, a novel [2]rotaxane based on an orthogonal H-bonded motif and 3,6-di(thiophenyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) with controlled topicity was successfully constructed, displaying excellent stimulated responses toward anion and solvent polarity. The extensive 1H &; 19F NMR titrations were lucidly revealed the binding site and the mode binding interaction as well. The preorganized host selectively recognized F- with high optical sensitivity and
reversibility via enhanced positive cooperativity and noncovalent interaction by evidence of a shorter
fluorescence lifetime. Therefore we developed a first prototype [2]rotaxane molecular shuttle for selective recognition of F- with high optical outputs.
II
In chapter three, four analogous polymers were systematically synthesized by copolymerization of
a 9-alkylidene-9H-fluorene monomer with various monomers, which contained a diketopyrrolopyrrole unit tethered with a dumbbell unit, a metalated [2]rotaxane, a demetalated orthogonal H-bonded [2]rotaxane, and a simple alkyl chain, to furnish P1, P2, P3, and P4, respectively, to investigate the supramolecular interactions of the mechanically interlocked rotaxane pendants and conjugated polymer backbones. Prevailing 1H NMR and UV-vis to NIR titration
profiles indicated that the novel polyrotaxane P3 showed a sensitive and reversible acid-base molecular switch capability via supramolecular interactions in contrast to the other polymers (P1, P2, and P3). Compared with the other polymers, P3 possessed a narrower bandgap, which was also confirmed by the computational study. Prominently, the monitoring of a controllable nano-self-assembly process of P3 was obtained by reversible acid-base molecular switch approaches. The
orthogonal H-bonded pendant [2]rotaxane unit and the steric demand of P3 judiciously allowed to morph into a hierarchical nanostructure via interconvertible H-bonds, anion-π and π-π stackings, as well as hydrophobic interactions. In chapter four, A facile and sensitive fluorescent probe for hydrazine based on phthalimide
appended hydrophilic naphthalimide was successfully constructed, displaying excellent colorimetric and ratiometric responses towards hydrazine via Ing-Manske phthalimide deprotection conditions in semi-aqueous buffer solution. The estimated detection limit was as low as 4.2 nM (hydrazine content = 1 ppb) far below than the threshhold limit value (TLV) of 10 ppb according to the U. S. Environmental Protection Agency (EPA). Prevailing detection of hydrazine in living cells of the current probe is demonstrated. Thus in conclusion, a novel archetype DPP based highly fluorescent [2]rotaxane was developed.
The remarkable stimulated responses towards solvent polarity and fluoride ion were discussed.
Moreover, the extended efforts of this current design into polyrotaxane architectures along with their
acid-base controllable hierarchical nanostructure formations via reversible optical molecular switch approaches coupled with various non-covalent interactions were discussed. Furthermore a novel fluorescent ratiometric chemodosimeter for hydrazine based on Ing-Manske phthalimide deprotection was presented in detail.
|
|---|
