Search

Your search keyword '"Waal, Bas F. M."' showing total 148 results
Start Over Author "Waal, Bas F. M."
148 results on '"Waal, Bas F. M."'

4. Self‐Assembly of Discrete Oligomers of Naphthalenediimides in Bulk and on Surfaces.

Author

Corbet, Christiaan H. W. A., van den Bersselaar, Bart W. L., de Waal, Bas F. M., Reynaerts, Robby, Mali, Kunal S., De Feyter, Steven, Jonas, Alain M., Meijer, E. W., and Vantomme, Ghislaine

Subjects
SOLID-liquid interfaces, OLIGOMERIZATION, CHEMICAL structure, INTERMOLECULAR interactions, OLIGOMERS, CRYSTALLIZATION
Abstract

Here, we report on the synthesis of discrete oligomers of alkyl‐bridged naphthalenediimides (NDIs) and study their molecular nanostructures both in bulk, in solution, and at the liquid‐solid interface. Via an iterative synthesis method, multiple NDI cores were bridged with short and saturated alkyl‐diamines (C3 and C12) or long and unsaturated alkyl‐diamines (u2C33 to u8C100) at their imide termini. The strong intermolecular interaction between the NDI cores was observed by probing their photophysical properties in solution. In bulk, the discrete NDI oligomers preferentially ordered in lamellar morphologies, irrespective of whether a saturated or unsaturated spacer was employed. Moreover, both the molecular architecture as well as the crystallization conditions play a significant role in the nanoscale ordering. The long unsaturated alkyl chains lead preferably to folded‐chain conformations while their saturated analogues form stretched arrangements. At the solution‐solid interface, well‐defined lamellar regions were observed. These results show that precision in chemical structure alone is not sufficient to reach well‐defined structures of discrete oligomers, but that it must be combined with precision in processing conditions. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

7. Tuning the donor–acceptor interactions in phase-segregated block molecules

Author

Lamers, Brigitte A. G., primary, van Son, Martin H. C., additional, de Graaf, Freek V., additional, van den Bersselaar, Bart W. L., additional, de Waal, Bas F. M., additional, Komatsu, Kazuki, additional, Sato, Hiroshi, additional, Aida, Takuzo, additional, Berrocal, José Augusto, additional, Palmans, Anja R. A., additional, Vantomme, Ghislaine, additional, Meskers, Stefan C. J., additional, and Meijer, E. W., additional

Published
2022
Full Text
View/download PDF

10. Multicomponent host-guest chemistry of carboxylic acid and phosphonic acid based guests with dendritic hosts: An NMR study

Author

Broeren, Maarten A. C., Meijer, E. W., de Waal, Bas F. M., van Genederen, Marcel H. P., Sanders, H. M. H. F., and Fytas, George

Subjects
Dendrimers -- Research, Phosphoric acid -- Chemical properties, Nuclear magnetic resonance spectroscopy -- Usage, Carboxylic acids -- Chemical properties, Chemistry
Abstract

A new methodology is introduced to get insights in the binding of carboxylic and phosphoric acid type guest molecules to dendrimers by making use of (super 13)C NMR and (super 31)P NMR. The method is applicable for any type of guest and host in chloroform and gives information about binding strength, binding stoichiometry and binding dynamics.

Published
2005

18. Supramolecular chemistry with ureido-benzoic acids

Author

Appel, Wilco P J, Nieuwenhuizen, Marko M L, Lutz, Martin, De Waal, Bas F M, Palmans, Anja R A, Meijer, E. W., Sub Crystal and Structural Chemistry, Crystal and Structural Chemistry, Macro-Organic Chemistry, Macromolecular and Organic Chemistry, Sub Crystal and Structural Chemistry, and Crystal and Structural Chemistry

Subjects
chemistry.chemical_classification, Chloroform, Chemistry(all), Hydrogen bond, Stereochemistry, Supramolecular chemistry, General Chemistry, Crystal structure, Polymer, Combinatorial chemistry, Supramolecular polymers, chemistry.chemical_compound, chemistry, Surface modification, Molecule
Abstract

The controlled self-assembly of multiple molecules into predefined architectures requires highly directional and controllable non-covalent interactions with a high association constant. Here, we introduce the self-complementary ureido-benzoic acid (UBA) quadruple hydrogen-bonding motif. The dimerization constant is of the order of 109 M-1 in chloroform, which makes it an excellent candidate for supramolecular chemistry in dilute conditions. The self-complementary quadruple hydrogen bonding was confirmed in the solid state by a crystal structure. The applicability of the motif in supramolecular polymers was evaluated by bis-UBA telechelic poly(ethylene-butylene) polymers, which showed a dramatic increase in mechanical properties upon functionalization. The potential of the UBA motif in supramolecular chemistry was further evaluated in solution. One of the synthesized UBA molecules revealed hydrogen bonding to NaPy at high concentrations in chloroform. However, upon dilution, the UBA:NaPy hydrogen bonding is disrupted and UBA homodimers are obtained. This shows the potential of NaPy as a supramolecular protective group for the UBA molecule, which can be deprotected upon dilution. Furthermore, the dimerization of the UBA motif was reversibly switched between the 'off' and 'on' states using base and acid, demonstrating an alternative method of influencing the UBA dimerization. Switching of a UBA molecule in the presence of UPy revealed that UBA dimerization can be selectively switched 'off' and 'on' in the presence of UPy dimers. These results show the applicability and great potential of the self-complementary quadruple hydrogen-bonding UBA motif for supramolecular chemistry. © 2014 the Partner Organisations.

Published
2014

19. The iterative synthesis of discrete dimethylsiloxane oligomers: A practical guide

Author

Lamers, Brigitte A. G., Waal, Bas F. M., and Meijer, E. W.

Abstract

Discrete dimethylsiloxane oligomers are interesting building blocks for the synthesis of high χ–low Nblock co‐oligomers (BCOs) forming highly organized nanostructures. Here, a practical guide to the synthesis of molecularly defined oligodimethylsiloxanes (oDMS) from 7‐mer to 40‐mer via a linear growth strategy is described. The iteration of a hydroxylation reaction and the condensation of mono‐ or bifunctional hydroxysiloxanes with chloro‐octamethyltetrasiloxane results in asymmetric and symmetric siloxanes, respectively. The synthesis contains critical washing and purification steps to remove minor amounts of low and high‐molecular weight byproducts, which are detected using Fourier transform infrared spectrometry, gas chromatography–mass spectrometry, and size‐exclusion chromatography. The oligomers are obtained on a multigram scale in yields of 94–50% and in high purity with only one molar mass detected. The formation of the chloride, hydroxide or hydride functional groups is adequately analyzed using 29Si NMR spectroscopy. The hydride terminated siloxane oligomers are used in Karstedt catalyzed hydrosilylation reactions with alkene‐functional substrates to obtain oDMS‐based oligomers and BCOs. Byproduct formation as a result of isomerization and reduction are followed by 1H NMR spectroscopy and minimized using dry conditions and low‐catalyst loadings. This work presents the synthesis of discrete oligo(dimethylsiloxane) with a degree of polymerization up to 40 repeating units using a linear, iterative growth strategy. The oligomers are obtained on a multigram scale and in high purity with only one molar mass detected. These are promising materials for the synthesis of discrete block co‐oligomers to obtain nanostructures with defined physical properties.

Published
2021
Full Text
View/download PDF

25. A Versatile Method for the Preparation of Ferroelectric Supramolecular Materials via Radical End-Functionalization of Vinylidene Fluoride Oligomers

Author

Garcia-Iglesias, Miguel, de Waal, Bas F. M., Gorbunov, Andrey V., Palmans, Anja R. A., Kemerink, Martijn, Meijer, E. W., Garcia-Iglesias, Miguel, de Waal, Bas F. M., Gorbunov, Andrey V., Palmans, Anja R. A., Kemerink, Martijn, and Meijer, E. W.

Abstract

A synthetic method for the end-functionalization of vinylidene fluoride oligomers (OVDF) via a radical reaction between terminal olefins and I-OVDF is described. The method shows a wide substrate scope and excellent conversions, and permits the preparation of different disc-shaped cores such as benzene-1,3,5-tricarboxamides (BTAs), perylenes bisimide and phthalocyanines (Pc) bearing three to eight ferroelectric oligomers at their periphery. The formation, purity, OVDF conformation, and morphology of the final adducts has been assessed by a combination of techniques, such as NMR, size exclusion chromatography, differential scanning calorimetry, polarized optical microscopy, and atomic force microscopy. Finally, PBI-OVDF and Pc-OVDF materials show ferroelectric hysteresis behavior together with high remnant polarizations, with values as high as P-r approximate to 37 mC/m(2) for Pc-OVDF. This work demonstrates the potential of preparing a new set of ferroelectric materials simply by attaching OVDF oligomers to different small molecules. The use of carefully chosen small molecules paves the way to new functional materials in which ferroelectricity and electrical conductivity or light-harvesting properties coexist in a single compound., Funding Agencies|Dutch Polymer Institute (DPI) [765]; Dutch Ministry of Education, Culture and Science [024.001.035]; European Research Council [246829]

Published
2016
Full Text
View/download PDF

31. Fragmentation of organic ions bearing fixed multiple charges observed in MALDI MS.

Author

Lou, Xianwen, Li, Bao, de Waal, Bas F. M., Schill, Jurgen, Baker, Matthew B., Bovee, Ralf A. A., van Dongen, Joost L. J., Milroy, Lech‐Gustav, and Meijer, E. W.

Subjects
MATRIX-assisted laser desorption-ionization, IONIZING radiation, DEGREE of ionization, ELECTROSPRAY ionization mass spectrometry, INTERMEDIATES (Chemistry)
Abstract

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS) was used to analyze a series of synthetic organic ions bearing fixed multiple charges. Despite the multiple intrinsic charges, only singly charged ions were recorded in each case. In addition to the pseudo-molecular ions formed by counterion adduction, deprotonation and electron capture, a number of fragment ions were also observed. Charge splitting by fragmentation was found to be a viable route for charge reduction leading to the formation of the observed singly charged fragment ions. Unlike multivalent metal ions, organic ions can rearrange and/or fragment during charge reduction. This fragmentation process will evidently complicate the interpretation of the MALDI MS spectrum. Because MALDI MS is usually considered as a soft ionization technique, the fragment ion peaks can easily be erroneously interpreted as impurities. Therefore, the awareness and understanding of the underlying MALDI-induced fragmentation pathways is essential for a proper interpretation of the corresponding mass spectra. Due to the fragment ions generated during charge reduction, special care should be taken in the MALDI MS analysis of multiply charged ions. In this work, the possible mechanisms by which the organic ions bearing fixed multiple charges fragment are investigated. With an improved understanding of the fragmentation mechanisms, MALDI TOF MS should still be a useful technique for the characterization of organic ions with fixed multiple charges. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

32. Supramolecular chemistry with ureido-benzoic acids

Author

Sub Crystal and Structural Chemistry, Crystal and Structural Chemistry, Appel, Wilco P J, Nieuwenhuizen, Marko M L, Lutz, Martin, De Waal, Bas F M, Palmans, Anja R A, Meijer, E. W., Sub Crystal and Structural Chemistry, Crystal and Structural Chemistry, Appel, Wilco P J, Nieuwenhuizen, Marko M L, Lutz, Martin, De Waal, Bas F M, Palmans, Anja R A, and Meijer, E. W.

Published
2014

35. End Groups of Functionalized Siloxane Oligomers Direct Block- Copolymeric or Liquid-Crystalline Self-Assembly Behavior.

Author

Helen Zha, R., de Waal, Bas F. M., Lutz, Martin, Teunissen, Abraham J. P., and Meijer, E. W.

Subjects
*SILOXANES, *OLIGOMERS, *DIMETHYLPOLYSILOXANES, *POLYMERIZATION, *DIBLOCK copolymers, *NANOSTRUCTURES, *MICROELECTRONICS
Abstract

Monodisperse oligodimethylsiloxanes end-func- liquid crystal block copolymer tionalized with the hydrogen-bonding ureidopyrimidinone (UPy) motif undergo phase separation between their aromatic end groups and dimethylsiloxane midblocks to form ordered nanostructures with domain spacings of <5 nm. The selfassembly behavior of these well-defined oligomers resembles that of high degree of polymerization (N)- high block interaction parameter (χ) linear diblock copolymers despite their small size. Specifically, the phase morphology varies from lamellar to hexagonal to body-centered cubic with increasing asymmetry in molecular volume fraction. Mixing molecules with different molecular weights to give dispersity >1.13 results in disorder, showing importance of molecular monodispersity for ultrasmall ordered phase separation. In contrast, oligodimethylsiloxanes end-functionalized with an O-benzylated UPy derivative self-assemble into lamellar nanostructures regardless of volume fraction because of the strong preference of the end groups to aggregate in a planar geometry. Thus, these molecules display more classically liquid-crystalline self-assembly behavior where the lamellar bilayer thickness is determined by the siloxane midblock. Here the lamellar nanostructure is tolerant to molecular polydispersity. We show the importance of end groups in high χ-low N block molecules, where block-copolymer-like self-assembly in our UPy-functionalized oligodimethylsiloxanes relies upon the dominance of phase separation effects over directional end group aggregation. [ABSTRACT FROM AUTHOR]

Published
2016
Full Text
View/download PDF

36. Controlled Supramolecular Oligomerization of C3-Symmetrical Molecules in Water: The Impact of Hydrophobic Shielding

Author

Besenius, Pol, primary, van den Hout, Kelly P., additional, Albers, Harald M. H. G., additional, de Greef, Tom F. A., additional, Olijve, Luuk L. C., additional, Hermans, Thomas M., additional, de Waal, Bas F. M., additional, Bomans, Paul H. H., additional, Sommerdijk, Nico A. J. M., additional, Portale, Giuseppe, additional, Palmans, Anja R. A., additional, van Genderen, Marcel H. P., additional, Vekemans, Jef A. J. M., additional, and Meijer, E. W., additional

Published
2011
Full Text
View/download PDF

40. Noncovalent synthesis of supramolecular dendritic architectures in water

Author

Broeren, Maarten A. C., primary, Linhardt, Jeffrey G., additional, Malda, Hinke, additional, de Waal, Bas F. M., additional, Versteegen, Ron M., additional, Meijer, Joris T., additional, Löwik, Dennis W. P. M., additional, van Hest, Jan C. M., additional, van Genderen, Marcel H. P., additional, and Meijer, E. W., additional

Published
2005
Full Text
View/download PDF

48. Nanopatterned Superlattices in Self-Assembled C2-Symmetric Oligodimethylsiloxane-Based Benzene-1,3,5-Tricarboxamides.

Author

García‐Iglesias, Miguel, de Waal, Bas F. M., de Feijter, Isja, Palmans, Anja R. A., and Meijer, E. W.

Subjects
*SUPERLATTICES, *METHYL cyclohexane, *CIRCULAR dichroism, *POLYDIMETHYLSILOXANE, *HYDROPHOBIC compounds, *BLOCK copolymers
Abstract

The synthesis of C3- and C2-symmetric benzene- 1,3,5-tricarboxamides (BTAs) containing well-defined oligodimethylsiloxane (oDMS) and/or alkyl side chains has been carried out. The influence of the bulkiness of the oDMS chains in the aggregation behavior of dilute solutions of the oDMSBTAs in methylcyclohexane was studied by temperature-dependent UV spectroscopy. The formation of hierarchically self-assembled aggregates was observed at different BTA concentrations, the tendency of aggregation increases by shortening or removing oDMS chains. Chiral BTAs were investigated with circular dichroism (CD) spectroscopy, showing a stronger tendency to aggregate than the achiral ones. Majority rules experiments show a linear behavior consistent with the existence of a high mismatch penalty energy. The most efficient oDMS-BTAs organogelators have the ability to form stable organogels at 5 mgmL-1 (0.75 wt%) in hexane. Solid-state characterization techniques indicate the formation of an intermolecular threefold hydrogen bonding between adjacent molecules forming thermotropic liquid crystals, exhibiting a hexagonal columnar organization from room temperature to above 150 °C. A decrease of the clearing temperatures was observed when increasing the number and length of the oligodimethylsiloxane chains. In addition to the three-fold hydrogen bonding that leads to columnar liquid crystalline phase, segregation between the oDMS and aliphatic chains takes place in the BTA functionalized with two alkyl and one oDMS chain leading to a superlattice within the hexagonal structure with potential applications in lithography. [ABSTRACT FROM AUTHOR]

Published
2015
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results