Pyridine-containing block copolymeric nano-assemblies obtained through complementary hydrogen-bonding directed polymerization-induced self-assembly in water

A diversity of pyridine-containing polymeric nanomaterials with controllable structures and multiple responses were developed through complementary hydrogen-bonding directed polymerization-induced self-assembly in aqueous solution.

Probing Orientation-Specific Charge-Dipole Interactions between Hexafluoroisopropanol and Halides: A Joint Photoelectron Spectroscopy and Theoretical Study

The interactions between hexafluoroisopropanol (HFIP) and halogen anions X^- (F^-, Cl^-, Br^-, and I^-) have been investigated using negative ion photoelectron (NIPE) spectroscopy and ab initio calculations. The measured NIPE spectrum of each [HFIP·X]^- (X = Cl, Br, and I) complex shows a pattern identical to the corresponding X^- by shifting to the high electron binding energy side, indicative of the formation of the [HFIP···X^-] structure in which X^- interacts with HFIP via charge-dipole interactions. However, the spectrum of [HFIP·F]^- appears completely different from that of F^- and is more similar to the spectrum of the deprotonated HFIP anion (HFIP_-H^-). The geometry and electron density calculations indicate that a neutral HF molecule is formed upon HFIP interacting with F^- via proton transfer, rendering a stable structure of [HFIP_-H···HF]^-. Two conformers of [HFIP_-H·HF]^- with HFIP being in synperiplanar and antiperiplanar configurations, respectively, are observed, providing direct experimental evidences to show the distinctly different and orientation-specific interactions between HFIP and halide anions.

Catalyst free removal of trithiocarbonate RAFT CTAs from poly(vinylpyridine)s using tris(trimethylsilyl)silane and light

Trithiocarbonate end groups on various polymers, including polyvinylpyridines, are reduced rapily and quantitatively using only tris(trimethylsilyl)silane and light.

Rotational spectra and theoretical study of tetramers and trimers of 2-fluoroethanol: dramatic intermolecular compensation for intramolecular instability

Cooperativity and chirality dominate in stabilizing the 2-fluoroethanol tetramer, thanks to a fully bifurcated C–H⋯F H-bond network.

RAFT Polymerization of Styrene and Maleimide in the Presence of Fluoroalcohol: Hydrogen Bonding Effects with Classical Alternating Copolymerization as Reference

The impacts of hydrogen bonding on polymerization behavior has been of interest for a long time; however, universality and in-depth understanding are still lacking. For the first time, the effect of hydrogen bonding on the classical alternating-type copolymerization of styrene and maleimide was explored. N-phenylmaleimide (N-PMI)/styrene was chosen as a model monomer pair in the presence of hydrogen bonding donor solvent 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), which interacted with N-PMI via hydrogen bonding. Reversible addition-fragmentation chain transfer polymerization (RAFT) technique was used to guarantee the "living" polymerization and thus the homogeneity of chain compositions. In comparison with the polymerization in nonhydrogen bonding donor solvent (toluene), the copolymerization in HFIP exhibited a high rate and a slight deviation from alternating copolymerization tendency. The reactivity ratios of N-PMI and St were revealed to be 0.078 and 0.068, respectively, while the reactivity ratios in toluene were 0.026 and 0.050. These interesting results were reasonably explained by using computer simulations, wherein the steric repulsion and electron induction by the hydrogen bonding between HFIP and NPMI were revealed. This work first elucidated the hydrogen bonding interaction in the classical alternating-type copolymerization, which will enrich the research on hydrogen bonding-induced polymerizations.

Toward alternating copolymerization of maleimide and vinyl acetate driven by hydrogen bonding

Herein, we report the solution copolymerization of N-propylmaleimide (MI) and vinyl acetate (VAc) in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and 1,4-dioxane.

Temperature programed photo-induced RAFT polymerization of stereo-block copolymers of poly(vinyl acetate)

Stereo-triblock copolymers of poly(vinyl acetate) are synthesized with controlled molecular weights based on a temperature-programed photo-induced RAFT in HFIP.

RAFT polymerization of N-vinylpyrrolidone mediated by cyanoprop-2-yl-1-dithionaphthalate in the presence of a fluoroalcohol: the possibility of altering monomer properties by hydrogen bonding?

This work illustrated the possibility of altering the monomer properties by using the hydrogen bonding interaction.