Chiroptical and colorimetric switches based on helical polymer-metal nanocomposites preparedviaredox metal translocation of helical polymer metal complexes

Abstract

A helical copoly(phenylacetylene) that follows a dynamic chiral accord effect has been designed to further synthetize dynamic chiral nanocomposites. Its two pendants are benzamides of (L)-methionine methyl ester [(L)-1, 20%]...

Stimuli-responsive synthetic helical polymers

“…248 In a different example, Freire explored the helix inversion of a PPA during a redox metal translocation process, a crucial step during the synthesis of helical poly(phenylacetylene)-metal nanocomposites. 249 A PPA copolymer made by two comonomers that contain the benzamides of methionine methyl ester [( l )- 105 ] and ( l )-alanine methyl ester [( l )- 106 ] as pendants in 0.2 ( l )- 105 /0.8 ( l )- 106 ratio—poly-[( l )- 105 0.2 - co -( l )- 106 0.8 ]—was prepared. In a low-polarity solvent environment such as CHCl 3 , both pendant groups adopt an anti -conformation that induces an M helix into the copolymer (Fig.…”

Size Control of Chiral Nanospheres Obtained via Nanoprecipitation of Helical Poly(phenylacetylene)s in the Absence of Surfactants

“…From these materials it is possible to create micelles, nanospheres or capsules, where the size and morphology control is a very important issue due to the properties associated to these parameters such as the surface area, diffusibility and mobility. Dynamic helical polymers [10–36] show interesting stimuli‐responsive properties [37] that allow controlling their helical sense and/or elongation. This fact makes these polymers attractive to be applied at the nanoscale level, where P / M dynamic chiral polymer particles can find potential applications in fields such as asymmetric catalyst, [38–39] CPL light‐emissive materials, [40–42] enantioseparation, [43] stimuli‐responsive particles, [44] crystallization, [45] chiral resolution, [46] drug delivery [47] and so on.…”

Stereocomplex Nanocomposite Switch Based on Dynamic Helical Polymer-Gold and Silver Nanoparticle Hybrid Materials

“…38−42 From previous studies, it is known that the dynamic behavior of the helical polymer in a dynamic helical polymer-MNP nanocomposite can be altered by the binding strength between the polymer and the MNP. 9 Thus, in the case of using PPAs bearing a thiol or thioether group as linking groups to the MNPs, it is necessary to prepare a copolymer due to the poor solubility of the homopolymers containing thiol or thioether groups in the monomer repeating units. 7,10 In the case of preparing a copolymer, it is necessary to consider all the chiral communication mechanisms that can emerge between the two components.…”

“…Metal nanoparticles (MNPs) have been exploited during the last decades by the scientific community due to their applications in fields such as theranostic, , sensing, or catalysis. , To apply these materials in different fields, and work under different conditionssolvent, temperature, etc.it is necessary to decorate the NMP surface with an appropriate coating, usually an organic molecule. Thus, in the literature, it is possible to find research articles dealing with the functionalization and postfunctionalization of the MNP surface, which include helical natural (DNA or peptides) and nonnatural macromolecules (helical polymers). − …”

“…From previous studies, it is known that the dynamic behavior of the helical polymer in a dynamic helical polymer-MNP nanocomposite can be altered by the binding strength between the polymer and the MNP . Thus, in the case of using PPAs bearing a thiol or thioether group as linking groups to the MNPs, it is necessary to prepare a copolymer due to the poor solubility of the homopolymers containing thiol or thioether groups in the monomer repeating units. , In the case of preparing a copolymer, it is necessary to consider all the chiral communication mechanisms that can emerge between the two components. Thus, when the copolymer is made up of two chiral monomers, a “Chiral Accord” or “Chiral Coalition” effect should occur between monomers to preserve the dynamic behavior and the screw sense excess in the copolymer, whereas if one of the monomers is chiral and the other nonchiral a “Sergeants and Soldiers” effect should be triggered within the copolymer series.…”