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We present time-resolved photoluminescence measurements on two series of oligo-p-phenylenevinylene materials that self-assemble into supramolecular nanostructures with thermotropic reversibility in dodecane. One set of derivatives form chiral helical stacks, while the second set form less organized “frustrated” stacks. Here we study the effects of supramolecular organization on the resonance energy transfer rates. We measure these rates in nanoassemblies formed with mixed blends of oligomers and compare them with the rates predicted by Förster theory. Our results and analysis show that control of supramolecular order in the nanometer length scale has a dominant effect on the efficiency and dimensionality of resonance energy transfer. [ABSTRACT FROM AUTHOR]

The electrical properties of supermolecular assemblies of oligo(p-phenylene vinylene) were studied. These materials self-assemble into well-defined cylindrical structures in solution with lengths in the range of 100 nm–10 μm and diameters between 5 and 200 nm. Atomic force microscopy showed that by adjusting the concentration, either individual molecular wires or a dense film could be deposited. The molecular wires showed poor electrical conduction. Several tests were performed that show that it was the molecular wires themselves, not the contacts, that limit the conductivity. [ABSTRACT FROM AUTHOR]

We present time-resolved photoluminescence measurements on two series of oligo-p-phenylenevinylene (OPV) materials that are functionalized with quadruple hydrogen-bonding groups. These form supramolecular assemblies with thermotropic reversibility. The morphology of the assemblies depends on the way that the oligomers are functionalized; monofunctionalized OPVs (MOPVs) form chiral, helical stacks while bifunctionalized OPVs (BOPVs) form less organized structures. These are therefore model systems to investigate the effects of supramolecular assembly, the effects of morphology, and the dependence of oligomer length on the radiative and nonradiative rates of π-conjugated materials. The purpose of this work is to use MOPV and BOPV derivatives as model systems to study the effect of intermolecular interactions on the molecular photophysics by comparing optical properties in the dissolved phase and the supramolecular assemblies. A simple photophysical analysis allows us to extract the intrinsic radiative and nonradiative decay rates and to unravel the consequences of interchromophore coupling with unprecedented detail. We find that interchromophore coupling strongly reduces both radiative and intrinsic nonradiative rates and that the effect is more pronounced in short oligomers. [ABSTRACT FROM AUTHOR]

Iterative tandem catalysis (ITC) is introduced as a flexible tool for obtaining chiral macromolecules from racemic or prochiral monomers. The principle of iterative tandem catalysis is proved and enzymatic ring-opening is combined with ruthenium-catalyzed racemization, yielding enantioenriched oligomers of 6-methyl-epsilon-caprolactone (6-MeCL).

The controlled magnetic deformation of spherical nanocapsules assembled from bolaamphiphilic sexithiophenes into oblate steroids using a gelation method is demonstrated. The method proves the unique opportunity to capture deformed nanocapsules permitting further investigations and potential device applications.

A study conducted to provide new insights into the relation between monomer configuration, conformation, and cyclization equilibria for bifunctional 2-ureido-4[1H]-pyrimidinone (UPy) derivatives, is presented. Information regarding the study of ring-chain transitions as well as for the design of helical polymers is given.

Research has been conducted on dendrimers. The authors describe the structural and physical properties of these compounds, the incorporation of these properties into supramolecular assemblies and the synthesis and interactions of the dendrimers with paraquat diol.

The supramolecular folding of amphiphilic heterograft copolymers equipped with dendritic pendants is investigated using a combination of proton nuclear magnetic resonance (1H NMR) spectroscopy, small‐angle X‐ray scattering, and circular dichroism spectroscopy. Hereto, the linear poly(ethylene glycol) pendants normally used to convey water compatibility are partially substituted with branched analogues. For one set of copolymers, second‐generation polyglycerol dendrons are directly attached to the polymer backbone, while for the other a hydrophilic linker is placed in between. The results show that the branching of the hydrophilic pendants affects the local structure of the folded copolymer but does not influence the overall conformation and single‐chain character of the folded copolymers in solution. All copolymers fold into 4–5 nm single‐chain polymeric nanoparticles with a very compact spherical morphology, independent of the dendritic content of the copolymer. Intriguingly, the incorporation of the dendritic pendants affects the formation of a structured interior even at low incorporation ratios. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 411–421 The supramolecular folding of amphiphilic heterograft copolymers equipped with dendritic pendants is investigated. Hereto, the linear poly(ethylene glycol) pendants normally used to convey water‐compatibility are partially substituted with branched analogues. The results show that the branching of the hydrophilic pendants affects the local structure of the folded copolymer but does not influence the overall conformation and single‐chain character of the folded copolymers in solution. [ABSTRACT FROM AUTHOR]

Investigates the effects of order and disorder on field-effect mobilities measured in conjugated polymer thin-film transistors. Interest in the use of conjugated polymers as active semiconductor in field-effect transistors; Experimental details; Result of the study.

Supramolecular polymers, which are non-covalently bonded and formed by self association of di or trifunctional monomers exhibit, by virtue of quadruple hydrogen bonds, many of the properties of normal high molecular weight polymers, e.g. a dynamic rubber plateau. We focus on the molecular and cooperative dynamics of self-assembled linear polymers and networks, studied by broadband dielectric relaxation spectroscopy (DRS) in the frequency range from [10.sup.-2] to [10.sup.6] Hz. The DRS analysis was backed up by dynamic mechanical and rheological experiments. In the high temperature region two loss processes ([Alpha] and [Alpha]*) show up, the relaxation times of which obey the Vogel-Fulcher-Tammann (VFT) law. The dielectric [Alpha] process is related to the dynamic glass-rubber transition and is slightly faster than the corresponding mechanical [Alpha] process. A slower (high-temperature) [Alpha]* relaxation is identified as chemical, corresponding to the mean lifetime of the hydrogen bonded linkages in the supramolecular chains. Its relaxation time [[Tau].sub.[Alpha]]* was found to be 1 to 2 decades larger than the terminal flow relaxation time, indicating that the relaxation of an entire chain is dominated by the joint dynamics of many hydrogen bonds. The [Beta] relaxation, observed in both DRS and dynamic mechanical analysis (DMA) at temperatures below [T.sub.g], arises from the local junction dynamics of hydrogen bonded units in the glassy state. Details of the temperature dependence and the shape of the loss peaks of the [Alpha] and [Alpha]* relaxations will be discussed in terms of temporary physical networks and cooperativity.