Influence of the halogen and organometallic function in a KCTP (Co)polymerization

Abstract

The effect of changing the halogen and the organometallic function in a Kumada Catalyst Transfer Polycondensation (KCTP) of poly(3‐alkylthiophene)s (P3AT) is investigated. On the one hand, the bromine substituent is replaced with chlorine in the commonly used 2‐bromo‐5‐chloromagnesio‐3‐hexylthiophene. The effect on the homopolymerization is clear, since the stickiness decreases remarkably, but copolymerizations are hardly affected when a chlorinated monomer is used. Second, the option of changing the organometallic function is considered. Because also organozinc compounds provide a controlled P3AT polymerization with Ni(dppp)Cl2, but are less reactive than organomagnesium compounds, the effect of using zinc in one monomer during a copolymerization is investigated. However, it is found that the organometallic functions exchange during mixing of the monomers. Consequently, no effect is observed during copolymerizations. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 3701–3706

Synthesis of conjugated copolymers by combining different coupling reactions

“…The combination of the Grignard reagent with the organozinc monomer was previously examined by our research group, and showed not only the formation of 1, but also equal amounts of 2. 16 In this study, a similar observation was made when the stannylated compound was combined with the Grignard reagent, although slightly longer mixing (10 minutes) at room temperature was required. Nevertheless, it clearly indicates that exchange occurs between the monomers.…”

“…These are chosen because (1) the synthesis of poly(thiophene) using different organometallic functions and catalysts is widely investigated and ( 2 S1, ESI). 16 In addition, they are known to randomly copolymerize when bearing the same organometallic function, so the effect of the different organometallic functions is easily detected. 16,17 The organometallic functions used in this study are (1) Grignard, (2) organozinc, (3) organoboron, (4) organotin, and (5) organogold (Table 1).…”

“…16 In addition, they are known to randomly copolymerize when bearing the same organometallic function, so the effect of the different organometallic functions is easily detected. 16,17 The organometallic functions used in this study are (1) Grignard, (2) organozinc, (3) organoboron, (4) organotin, and (5) organogold (Table 1). Although the latter is quite new, Kumada-Tamao Corriu, Negishi, Suzuki-Miyaura and Migita-Kosugi-Stille couplings, respectively, have already been widely used in the synthesis of conjugated polymers.…”

The role of halogens in the catalyst transfer polycondensation for π-conjugated polymers

“…Since the discovery of the quasi-living synthesis of polythiophenes, considerable effort has been devoted to understanding the underlying reaction mechanisms and expanding the scope of applicable monomers. Nickel( ii )diphosphine catalysts, such as 1,2-bis-(diphenylphosphino)propane nickel( ii ) chloride (Ni(dppp)Cl 2 ) and 1,2-bis-(diphenylphosphino)ethane nickel( ii ) chloride (Ni(dppe)Cl 2 ), are most frequently used for the controlled synthesis of electron-rich conjugated polymers, and their polymerizations are often used as model systems for studying the mechanism of KCTP 7…”

The influence of branching on the Kumada catalyst transfer condensative polymerization of 3-alkylthiophenes

“…In the last decade, the mechanism of the catalyst transfer condensative polymerization (CTCP) of especially thiophene monomers has thoroughly been investigated. 1 This includes the influence of the ligand of the catalyst [2][3][4] , the halogen on the monomer 5,6 , the use of different precursor monomers and synthetic methods for obtaining the monomers [6][7][8][9][10] .…”