Tri‐ and Tetracarbanionic Initiators by a Lithium/Halide Exchange Reaction: Application to Star‐Polymer Synthesis

Abstract

A family of polycarbanionic initiators: Bis‐, tris‐, and tetrakisaryl lithium compounds (see scheme) were synthesized from the corresponding aryl halides by simple halogen/lithium exchange reactions. These polylithiated species were used to prepare telechelic and three‐ and four‐armed star polystyrene and polybutadiene homopolymers, as well as poly(styrene‐block‐butadiene‐block‐methyl methacrylate) star block terpolymers.

Constructing Regioregular Star Poly(3-hexylthiophene) via Externally Initiated Kumada Catalyst-Transfer Polycondensation

“…Proof of the star-like structure of the polymers in many cases is a highly challenging task . However, in this work the assignment and integration of the 1 H NMR spectra are unequivocal.…”

Multi‐Compartment Unimolecular Micelles from (ABC)n Multi‐Arm Star Triblock Terpolymers

“…[32][33][34][35] The present work aims to combine the linear ABC triblock terpolymer structure with the star architecture (Scheme 1). [36,37] Thus, novel star triblock terpolymers comprising ABC arms [each consisting a the hydrophilic hexa(ethylene glycol) methacrylate (HEGMA) block, a 2-(dimethylamino)ethyl methacrylate (DMAEMA) block, and a hydrophobic methyl methacrylate (MMA) block], emanating from a common nodule were studied in solution. To the best of our knowledge, this is the first time that this type of architecture has been studied in aqueous selective media.…”

Restraining the associations of anthracene fluorophore by chemically linking to poly(methyl methacrylate)

“…Two primary considerations were for the polymerization. First, lithiated carbanion was generated at low temperature and in the presence of chelating 2‐hydroxylethanol to pull out the lithium cation and to generate anion with better activity 16. Second, in addition to the direct process, polymerization of MMA was also performed with the participation of 1,1‐diphenylethene (DPE), which is supposed to reduce the possible side reaction originating from the nucleophilic addition of the carbanion on the ester carbonyl group of MMA monomer.…”

“…Sec ‐Butyllithium, diphenylethylene, 9,10‐dibromoanthracene, and anthracene were purchased from Aldrich Chemical and used directly without purification. PMMA ( M n = 14,000, PDI = 1.41) was prepared as described previously16 and was used directly to prepare blend with anthracene.…”