Synthesis and characterization of a polyisocyanide with thioether pendant caused an oxidation-triggered helix-to-helix transition

Stimuli responsive helical polymers have attracted wide attention and many polymers responsive to the external stimuli have been synthesized. But, only a few examples have been reported regarding the redox-induced helicity inversion helical polymers. The polyisocyanide including thioether pendant (poly-MBTIP) was synthesized by polymerization of methyl (R)-3-(benzylthio)-2-isocyanopropanoate (MBTIP) monomer using NiCl2·6H2O as catalytic agent in dry DCM. The chiroptical and oxidation properties of the poly-MBTIP are investigated. The poly-MBTIPs exhibit intense specific optical rotations and Cotton effects compared to the monomer, strongly suggesting a helical conformation of the polymer backbone. Additionally, the thioether pendant of poly-MBTIP backbone was oxidized to sulfoxide group by H2O2. Interestingly, the specific optical rotations and Cotton effects of poly-MBTIP oxidized are reversed, probably suggesting a helical conformation inversion.

Chemoselective oxidation of phenoxathiin-based thiacalix[4]arene and the stereoselective alkylation of products

Phenoxathiin-based thiacalix[4]arene was subjected to exhaustive oxidation. Depending on the reaction conditions, the macrocyclic systems bearing four sulfonyl groups or three sulfonyl and one sulfoxide group are available in high yields.

The Complexation of Calix[6]Arene Sulfoxide Derivative with Uranium

Calix[6]arene carbon chain alkyl sulfoxide derivative have been successfully synthesized. IR spectra confirmed the introduction of sulfoxide group on calix[6]arene. UV spectra indicated that calix[6]arene sulfoxide derivative has a high complexation of uranium. The coordination ratio between the calix[6]arene sulfoxide derivative with uranium is 3:2, which was determined by Job’s method. Extraction experiments showed that the extraction efficiency of uranium is able to achieve 73.8%, which suggested the potential application of calix[6]arene sulfoxide derivative as an excellent uranium extraction agent.