1177261-93-6Relevant articles and documents
Novel malachite green- and rhodamine B-labeled cationic chain transfer agents for RAFT polymerization
Beija, Mariana,Afonso, Carlos A.M.,Farinha, José Paulo S.,Charreyre, Marie-Thérse,Martinho, José M.G.
experimental part, p. 5933 - 5946 (2012/04/10)
Two novel cationic RAFT agents have been synthesized, one labeled with a Malachite Green (MG) dye and another with a Rhodamine B (RhoB) dye. MG-labeled dithiobenzoate (MGEDBA) was prepared in a straightforward manner after synthesis of MG-ethylammonium chloride that reacted with a precursor dithiobenzoate bearing an activated ester function. However, the analogous reaction with RhoB amino derivative led to a mixture of dithiobenzoate and thioamide derivatives. An alternative approach yielded the RhoB-labeled RAFT agent (RhoBEDBA) with complete conversion. The purification of these dye-labeled RAFT agents was very challenging because of their dual nature (aromatic and ionic). Both MGEDBA and RhoBEDBA were efficient RAFT chain transfer agents to control the polymerization of N,N-dimethylacrylamide (DMA). The resulting α-end-labeled MG- and RhoB-PDMA samples presented low dispersities (1.2) and both chain-ends were preserved. Finally, we showed that the attachment of RhoB and MG to the PDMA polymer chain-end did not influence the photophysical properties of these dyes. Therefore, these new dye-labeled RAFT agents can be used to prepare various labeled polymers and especially water-soluble ones, to study their conformation and dynamics in solution or at interfaces using fluorescence methods, or as labeled probes for imaging and/or diagnosis purposes.
