Development of catalyst‐transfer condensation polymerization. Synthesis of π‐conjugated polymers with controlled molecular weight and low polydispersity

Abstract

ABSTRACT:We describe the development of chain-growth condensation polymerization for the synthesis of well-defined p-conjugated polymers via a new polymerization mechanism, catalysttransfer polymerization. We first studied the condensation polymerization of Grignard-type hexylthiophene monomer with a Ni catalyst as a part of our research on chain-growth condensation polymerization, and found that this polymerization also proceeded in a chain-growth polymerization manner. However, the polymerization mechanism involving the Ni catalyst was different from that of previous chain-growth condensation polymerizations based on substituent effects; the Ni catalyst catalyzed the coupling reaction of the monomer with the polymer, followed by the transfer of Ni (0)

The Effects of Binding Ligand Variation on the Nickel Catalyzed Externally Initiated Polymerization of 2‐Bromo‐3‐hexyl‐5‐iodothiophene

“…The reason for the decrease in regioregularity when using dppf compared to PPh 3 is not entirely clear (see below), although other researchers have observed difficulties in the synthesis of high molecular weight and high regioregular P3HT using this ligand. [32] N. Doubina The use of dppe afforded only non-phenyl initiated P3HT with lower regioregularity than is observed for normal P3HT synthesis using NiCl 2 (dppe). [32] In the case where dppp was used, the isolated polymeric material contained multiple unidentifiable peaks in the 1 H NMR and did not display any degree of regio control, which is surprising, considering NiCl 2 (dppp) as the best performing catalyst for the synthesis of P3HT via the Yokozawa method.…”

“…[32] N. Doubina The use of dppe afforded only non-phenyl initiated P3HT with lower regioregularity than is observed for normal P3HT synthesis using NiCl 2 (dppe). [32] In the case where dppp was used, the isolated polymeric material contained multiple unidentifiable peaks in the 1 H NMR and did not display any degree of regio control, which is surprising, considering NiCl 2 (dppp) as the best performing catalyst for the synthesis of P3HT via the Yokozawa method. [32] MALDI-TOF analysis of the P3HT synthesized with both dppe and dppp only showed peaks corresponding to H-Br and Br-Br terminated P3HT.…”

“…[32] In the case where dppp was used, the isolated polymeric material contained multiple unidentifiable peaks in the 1 H NMR and did not display any degree of regio control, which is surprising, considering NiCl 2 (dppp) as the best performing catalyst for the synthesis of P3HT via the Yokozawa method. [32] MALDI-TOF analysis of the P3HT synthesized with both dppe and dppp only showed peaks corresponding to H-Br and Br-Br terminated P3HT. The M n of the P3HT synthesized using dppe was %7.5 kDa and the PDI was 1.4.…”

“…[32] In order to investigate, this 1 equiv. of dppp was added to Ni(COD) 2 in THF and monitored by 31 P{H} NMR.…”

Transition-Metal-Catalyzed Highly Regio- and Stereoselective Co-Polymerization of Dialkynylbenzene with Benzenedithiol Leading to Poly(Phenylene Vinylene Sulfide)

“…To control the chemical or electrical properties of polymer, the development of highly selective synthetic methods of them is of great importance [1][2][3][4][5][6][7][8][9]. Transition-metal-catalyzed co-polymerization methods are one of the most suitable candidate for highly selective synthesis of -conjugate polymers, and indeed poly(phenylene) and poly(phenylene vinylene) can be prepared by this method [10][11][12][13][14][15].…”