Photochemically Induced Folding of Single Chain Polymer Nanoparticles in Water

Abstract

We pioneer the synthesis of fluorescent single chain nanoparticles (SCNPs) via UV-light induced folding based on tetrazole chemistry directly in pure water. Water-soluble photoreactive precursor polymers based on poly(acrylic acid) (PAA) bearing tetrazole, alkene and tetraethylene glycol monomethyl ether moieties, (PAA n (Tet/p-Mal/TEG)), or simply tetrazoles moieties, PAA n (Tet), were generated via RAFT polymerization. While tetrazole, ene, and acrylic acid containing polymers fold via dual nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) as well as nitrile iminecarboxylic acid ligation (NICAL), tetrazole and acrylic acid only functional prepolymers fold exclusively via NICAL. A detailed study of the underpinning photochemistry of NITEC and NICAL is also included. The resulting water-soluble SCNPs were carefully characterized via analytical techniques such as NMR, UV−vis, and fluorescence spectroscopy, as well as SEC and DLS.

Molecular Bottle Brushes with Positioned Selenols: Extending the Toolbox of Oxidative Single Polymer Chain Folding with Conformation Analysis by Atomic Force Microscopy

“…More recently, block and statistical copolymers have been exploited to insert intramolecular bridges and thereby inducing single chain folding . Covalent, dynamic covalent, and supramolecular bonds were used to generate static or dynamic single chain folding . Elegant supramolecular single polymer chain compactions based on single or combination of orthogonal hydrogen‐bonding tectons have been thoroughly reported …”

“…[21][22][23][24][25] Covalent, dynamic covalent, and supramolecular bonds were used to generate static or dynamic single chain folding. [26][27][28] Elegant supramolecular single polymer chain compactions based on single or combination of orthogonal hydrogen-bonding tectons have been thoroughly reported. [29][30][31] polymer chemistry, which aims at monodisperse macromolecules from fully synthetic monomer alphabets, polymers with discrete sequences get available.…”

Amphiphilic Janus Twin Single‐Chain Nanoparticles

“…An intramolecular cross-linking reaction, conducted in ad ilute polymer solution with ac oncentration below the overlap concentration, resultsi nt he formation of SCNPs. [31][32][33][34][35][36] The methods for intrachain folding/collapse of individual polymer chains are catalogued into intrachain homocoupling, [37] intrachain heterocoupling [38] and crosslinking induced collapse. [39,40] Covalent and non-covalent interactions have been used in the synthesis of SCNPs, and functional/stimuli-responsive SCNPs have been prepared.…”

Protection‐Group‐Free Synthesis of Sequence‐Defined Macromolecules via Precision λ‐Orthogonal Photochemistry

“…[8] Herein, we are introducing av ersatile completely protection-group-free strategy for the synthesis of monodisperse sequence-defined macromolecules by combining two photosensitive groups activated in a l-orthogonal fashion (Scheme 1). [11] a-Methyl benzaldehydes entail photo-caged UV responsive dienes which undergo [4+ +2] Diels-Alder (DA) cycloadditions [2c, 10] at 365 nm in presence of dienophiles such as fumarates.C ombining both photoactive groups in one Scheme 1. [1h,7a, 9] Our previous approaches reported ap hotochemical protocol relying on benzaldehydes and furan caged maleimides to afford sequence-defined macromolecules.…”

“…Ap yrenefunctionalized tetrazole is visible-light responsive and forms an itrile imine upon irradiation at 410 nm, which can be exploited to perform an itrile imine-carboxylic acid ligation (NICAL). [11] a-Methyl benzaldehydes entail photo-caged UV responsive dienes which undergo [4+ +2] Diels-Alder (DA) cycloadditions [2c, 10] at 365 nm in presence of dienophiles such as fumarates.C ombining both photoactive groups in one Scheme 1. Sequential light-induced chain extension based on two monomers.…”