RAFT Polymerization with Triphenylstannylcarbodithioates (Sn-RAFT)

Dual Function of β-hydroxy Dithiocinnamic Esters: RAFT Agent and Ligand for Metal Complexation

The reversible addition-fragmentation chain-transfer (RAFT) process has become a versatile tool for the preparation of defined polymers tolerating a large variety of functional groups. Several dithioesters, trithiocarbonates, xanthates, or dithiocarbamates have been developed as effective chain transfer agents (CTA), but only few examples have been reported, where the resulting end groups are directly considered for a secondary use besides controlling the polymerization. We here demonstrate that β-hydroxy dithiocinnamic esters represent a hitherto overlooked class of materials, which were originally designed for the complexation of transition metals but might as well act as reversible CTA. Modified with a suitable leaving group (R-group), these vinyl conjugated dithioesters indeed provide reasonable control over the polymerization of acrylates, acrylamides, or styrene via the RAFT process. Kinetic studies revealed linear evolutions of molar mass with conversion, while different substituents on the aromatic unit had only a minor influence. Block extensions prove the livingness of the polymer chains, although extended polymerization times may lead to side reactions. The resulting dithiocinnamic ester end groups are still able to form complexes with platinum, which verifies that the structural integrity of the end group is maintained. These findings open a versatile new route to tailor-made polymer bound metal complexes. This article is protected by copyright. All rights reserved.

RAFT dispersion polymerization of N,N-dimethylacrylamide in a series of n-alkanes using a thermoresponsive poly(tert-octyl acrylamide) steric stabilizer

Poly(tert-octyl acrylamide)-poly(N,N-dimethylacrylamide) nanoparticles are prepared by RAFT dispersion polymerization at 70 °C in various n-alkanes. Thermoreversible flocculation occurs in higher n-alkanes on cooling to 20 °C.

Manganese phosphinocarbodithioate for RAFT polymerisation with sunlight-induced chain end post-treatment

A new manganese complex of the formula Cp(CO)₂MnP(Ph)₂C(S)SCH(CH₃)Ph is an efficient RAFT agent for the preparation of SH-terminated polymers by simple visible light photocleavage of the organometallic end-group.