Conjugated graft copolymers consisting of a poly(3-hexylthiophene) (P3HT) backbone and poly(9,9'-dioctylfluorene) side chains (PF) with different grafting degrees were synthesized by the CuAAC reaction. The properties of these materials were studied by UV-Vis and fluorescence spectroscopy. The former technique provides insight in their self-assembly, while the latter is used to study the energy funneling from the PF side chains to the P3HT backbone. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1252–1258

This article deals with the Kumada Catalyst Transfer Polycondensation (KCTP) of 4,7-dioctylbenzo[2,1-b:3,4-b']dithiophene (BDP-Oct) using Ni(II) catalyst or In/cat combination. A combination of MALDI MS, GPC, and ³¹P NMR spectroscopy is used to reveal the failure of the KCTP of this particular monomer. Intermolecular transfer reactions to monomer appeared to prevent the formation of polymer. This result is remarkable, since isomeric benzo[1,2-b:4,5-b']dithiophene polymerizes in a controlled way. The presence of a “non-aromatic double bond” in annulated monomers is discussed. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1706–1712

In this contribution, we report the synthesis of chiral all-conjugated branched poly(phenylene ethynylenes) with a controlled amount of branching. Subsequently, the self-assembly of these PPEs is studied by means of UV–vis, fluorescence spectroscopy, and DSC and the influence of branching is investigated. Finally, CD-spectroscopy is used to study the influence of branching and self-assembly on the chiral expression of these polymers. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 79–84

A series of poly(3-alkylthiophene)s (P3ATs) (P1–P5) has been synthesized via a Ni(dppp)-mediated polymerization, varying the bulkiness of the alkyl side chains in order to investigate the influence of the bulkiness of the alkyl substituent on the aggregation and magnetic properties of P3ATs. UV–Vis spectroscopy, performed in solution as well as in film, shows that the stacking of the polymers becomes more complicated as the bulkiness of the side chains increases. Both the π-interactions and the planarization of the polymer chains are diminished. While aggregation is absent in poor solvent for the polymer with the most bulky side chains, aggregation was present in film, albeit slowed down. This behavior was also confirmed by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) experiments. Electron spin resonance (ESR) measurements, performed at 300 K on powders, confirmed the trend of decreasing supramolecular order with increasing bulkiness of the side-chain. Magnetization measurements, performed at 5 and 300 K, are in line with our hypothesis on the influence of π-interactions and the fraction of planar polymer chains on the coercivity and saturation magnetization, respectively. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 76–86

The formation in solution of a supramolecular graft copolymer bearing conjugated blocks is demonstrated using diffusion ordered NMR spectroscopy (DOSY). A tailor-made poly(3-(2-ethylhexyl)thiophene) (P3EHT) with a phenol end group is synthesized. For this purpose, the chain-growth mechanism of the polymerization of 2-bromo-5-chloromagnesio-3-alkylthiophenes in the presence of a Ni(dppp) catalyst (dppp = 1,3-bis(triphenylphosphino)propane) is exploited, as it enables the use of functionalized initiators to introduce specific end groups. The so-obtained polythiophene was subsequently mixed in solution with poly(4-vinylpyridine) (P4VP) to enable phenol-pyridine hydrogen bonding. The formation of the supramolecular graft copolymer is studied using DOSY-measurements. Based on the results thereof, the amount of P3EHT attached to the P4VP is calculated and the association constant of the hydrogen bond is estimated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 804–809

The synthesis and chiroptical properties of a series of meta-arylenes, equipped with chiral oligo(phenylene vinylene) (OPV) side chains, are presented. How the OPV side chain contributes to the optical properties of the polymer is investigated. Secondly, the influence of the distance of the chiral moieties, placed on the OPV side chain, to the polymer main chain is investigated, which shows that, in order to induce any chiral effects, these chiral moieties need to be placed in the ß-position near the polymer main chain. Finally, it is shown that long (a)chiral, lateral alkoxy chains on the OPV side chain prevent the polymers from adopting a helical conformation and result in the formation of lateral (a)chiral stacks of different polymer chains.

This manuscript investigates the possibilities to obtain helical conjugated polymers following a controlled chain-growth polymerization mechanism with external initiation. Attempts to prepare poly(3,6-(9,10-di(octyloxy))phenanthrene)s with the existing chain-growth mechanisms using existing Kumada or Negishi couplings were unsuccessful because of the difficulty to quantitatively prepare the Grignard metathesis reagent starting from the envisaged precursor, namely 3,6-dibromo-(9,10-di(octyloxy))phenanthrene. On the other hand, a Suzuki–Miyaura coupling polymerization using Pd(P^tBu₃) as the catalyst clearly allows the polymerization to proceed. The reaction conditions were optimized and an in-depth study with gel permeation chromatography and matrix-assisted laser desorption ionization time-of-flight (MALDI-ToF) of the underlying mechanisms was performed. Nevertheless, a prolonged chain-growth mechanism was not achieved for the targeted polymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 5067–5074

This paper presents the synthesis and characterization of low-bandgap materials based on cyclopenta[1,2-b;3,4-b′]dithiophene (CPDT). An array of electron-poor monomers is synthesized and used to prepare homo- and alternating donor–acceptor copolymers. This yields polymers with low bandgaps (E_g = 1.12–1.23 eV) and broad light absorption (400–1100 nm). The influence of the electron-withdrawing substituent and the donor material on the polymer properties is studied. It is demonstrated that the low bandgap is not a result of intramolecular charge transfer, but of a transition localized in the electron-poor CPDT monomer. The bandgap can be correlated with the substituent on the CPDT monomer and is relatively independent of other parameters, resulting in materials with an easily tunable bandgap.

This manuscript reports a universal chain-growth polymerization protocol for conjugated polymers. Herein, the Pd-based catalyst moiety dissociates from the growing active center into the solution and therefore, the controlled chain-growth character is not relying on any specific, system-related complexation, as is the case in polymerization methods reported before. This makes the protocol applicable on a broad range of monomers and, furthermore, also allows an easy one-pot synthesis of block-copolymers by successive monomer addition. A chain-growth polymerization mechanism for poly(3-hexylthiophene) (P3HT) and poly(9,9-dioctylfluorene) (PF) and all-conjugated block-copolymers of them is presented. Moreover, the sequence of monomer addition in the synthesis of these conjugated block-copolymers is unimportant, which is unique. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

The synthesis, aggregation, and optical properties of a chiral, regioregular polythiophene, substituted with a conjugated substituent, are described. The polymer was prepared using a Stille coupling reaction. The fact that the side-chain contributes to the absorption (UV-vis), emission (fluorescence), and redox behavior (cyclic voltammetry) of the material demonstrates that the substituent contributes to the electronic properties. It was shown that the conjugated side-chain chirally stacks in conditions in which the polymer backbone aggregates, which demonstrates the ability of conjugated polymers to induce a (chiral) lamellar organization of conjugated moieties, present in their side-chain. The aggregation of both the side-chain and the backbone was monitored using UV-vis and CD spectroscopy. Finally, it is shown that the conjugated side-chain can selectively be oxidized, without oxidizing the polythiophene backbone. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1891–1900, 2009

A hyperbranched poly(arylene oxindole), a poly(methacrylate), and a dendrimer, to which the same nonlinear optical chromophore was attached via a small, rigid spacer, were prepared. The difference in hyper-Rayleigh scattering intensities was measured and compared. From this study, it was concluded that the chromophores, and hence the functional groups in the macromolecule before functionalization, are orientationally correlated in the dendrimer, whereas they are not in the linear and hyperbranched polymer. More in particular, the chromophores in the dendrimer are fixed in a centrosymmetric way because of the globular structure, whereas there is no orientational correlation between the chromophores in linear and hyperbranched polymer. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3740–3747, 2009

New functionalized, (a)chiral poly(phenylene-alt-bithiophene)s were prepared and their chiroptical properties were studied. The polymers were prepared by a Stille coupling reaction and were functionalized with protected carboxylic acid and amino functions (tert-butyl ester and BOC respectively). The polymers are present as well conjugated rigid rods in solution, which (chirally) aggregate in nonsolvents and film. In a next step, the protecting group (tert-butyl ester in case of the carboxylic acid) was removed. Aggregation of this polymer can be induced by addition of amines; if chiral amines are used, the polymer chains chirally stack. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4817–4829, 2008