Excitation energy transfer of porphyrin in polymer thin films by time-resolved scanning near-field optical microspectroscopy

Triple Noncovalent-Interaction-Containing Supramolecular Polymer Vesicle Chemosensors with Dynamically Tunable Detection Ranges

Chemosensors (CSs) with dynamically tunable detection ranges have important significance for their expansion in practical applications; however, most CSs possess an unchangeable detection limit. In this work, we report the first example of a supramolecular polymer vesicle (SPV) chemosensor with a dynamically tunable detection range. SPVs containing porphyrin (PP) moieties and β-cyclodextrin (β-CD)/azobenzene (Azo) host-guest interactions were first constructed. The obtained SPVs were used to detect Zn²⁺ with a high selectivity and sensitivity over a wide detection limit range of 8.67×10^-9 to 1.99×10^-11 under UV light irradiation. The corresponding sensing mechanism was attributed to the synergistic effects of the triple noncovalent interactions, including the metal-ligand coordination of PP/Zn²⁺ and the double host-guest interactions of β-CD/Azo and β-CD/PP.

Post-polymerization of preorganized assemblies for creating shape-controlled functional materials

Combination of supramolecular chemistry with molecular recognition has been successfully applied to creating large superstructures with a wide variety of morphologies. Control of shapes and patterns of ordered molecular assemblies in nano and micro scales has attracted considerable interest as promising bottom-up technology. It is known, however, that these molecular assembling superstructures are fragile, reflecting the characteristic of the non-covalent interaction, a driving force operating in these molecular systems. In fact, they easily collapse or change by small perturbation in the environmental conditions. Thus, over the last decade, researchers have been seeking possible methods for the immobilization these superstructures. This critical review focuses on recent advances in in situ post-modification under the influence of the molecular assemblies as templates and polymerization of ordered molecular assemblies such as organogel fibers and crystals to preserve their original superstructures and intensify their mechanical strength.

Nano-rod structure of poly(ethylenedioxythiophene) and poly(pyrrole) as created by electrochemical polymerization using anionic porphyrin aggregates as template

It was found that a one-dimensional rodlike structure of 5,10,15,20-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) in water acts as a powerful template for electrochemical polymerization of ethylenedioxathiophene (EDOT) and pyrrole on an ITO electrode. Examination using CV and UV-vis spectroscopic examinations established that J-aggregated TPPS molecules are entrapped in the resultant poly(EDOT) and poly(pyrrole) films. SEM observation established that these monomers are electrochemically oxidized to grow up to a nanosized rodlike structure, reflecting the aggregation structure of TPPS. [structure: see text]