Richard A. van Delden
University of Groningen
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Richard A. van Delden.
Angewandte Chemie | 1999
Bernard Feringa; Richard A. van Delden
Biomolecular homochirality, the origin of which is still a puzzle, has challenged scientists to design chemical systems that provide chiral molecules through absolute asymmetric synthesis and to amplify a small stereochemical bias in such systems. The photoresolution of the enantiomers of helical-shaped, sterically overcrowded alkene 1 with circularly polarized light and the transduction of the stereochemical information by triggering the helical arrangement of a large collection of achiral molecules in a twisted nematic liquid crystalline phase (2) are examples of control and amplification of chirality.
Nature | 2005
Richard A. van Delden; Matthijs K. J. ter Wiel; Michael M. Pollard; Javier Vicario; Nagatoshi Koumura; Ben L. Feringa
Molecules capable of mimicking the function of a wide range of mechanical devices have been fabricated, with motors that can induce mechanical movement attracting particular attention. Such molecular motors convert light or chemical energy into directional rotary or linear motion, and are usually prepared and operated in solution. But if they are to be used as nanomachines that can do useful work, it seems essential to construct systems that can function on a surface, like a recently reported linear artificial muscle. Surface-mounted rotors have been realized and limited directionality in their motion predicted. Here we demonstrate that a light-driven molecular motor capable of repetitive unidirectional rotation can be mounted on the surface of gold nanoparticles. The motor design uses a chiral helical alkene with an upper half that serves as a propeller and is connected through a carbon–carbon double bond (the rotation axis) to a lower half that serves as a stator. The stator carries two thiol-functionalized ‘legs’, which then bind the entire motor molecule to a gold surface. NMR spectroscopy reveals that two photo-induced cis-trans isomerizations of the central double bond, each followed by a thermal helix inversion to prevent reverse rotation, induce a full and unidirectional 360° rotation of the propeller with respect to the surface-mounted lower half of the system.
Angewandte Chemie | 1999
Ben L. Feringa; Richard A. van Delden
Die Homochiralitat der Biomolekule, deren Ursprung noch immer ein Ratsel ist, hat Wissenschaftler herausgefordert, chemische Systeme zu entwerfen, in denen chirale Molekule durch absolute asymmetrische Synthese erzeugt werden und ein kleiner Enantiomerenuberschus verstarkt werden kann. Die photochemische Trennung der Enantiomere des helicalen, sterisch uberfrachteten Alkens 1 mit circular polarisiertem Licht und das Weiterleiten der stereochemischen Information durch Triggern der helicalen Anordnung einer grosen Ansammlung von achiralen Molekulen in einer verdrillten nematischen flussigkristallinen Phase (2) sind Beispiele fur die Kontrolle und Verstarkung von Chiralitat.
Organic and Biomolecular Chemistry | 2003
Richard A. van Delden; Nagatoshi Koumura; Am Schoevaars; Auke Meetsma; Bernard Feringa
A newly designed donor-acceptor substituted molecular motor 1 allows unidirectional rotation driven by visible light and shows some unique photophysical properties.
Chemical Science | 2010
Gregory T. Carroll; Michael M. Pollard; Richard A. van Delden; Bernard Feringa
Using circular dichroism (CD) spectroscopy, we show that light-driven rotary molecular motors based on overcrowded alkenes can function in a self-assembled monolayer on semi-transparent gold films.
Chemistry: A European Journal | 2008
Michael M. Pollard; Matthijs K. J. ter Wiel; Richard A. van Delden; Javier Vicario; Nagatoshi Koumura; Coenraad R. van den Brom; Auke Meetsma; Bernard Feringa
We report the synthesis of unidirectional light-driven rotary molecular motors based on chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of (1)H and (13)C NMR, UV/Vis and CD spectroscopy, we show that these motors preserve their photochemical and thermal behaviour after they have been attached to gold nanoparticles. Furthermore, we describe the synthesis of (2)H- and (13)C-labelled derivatives that were used to verify the unidirectionality of the rotary cycle of these motors both in solution and while grafted to gold nanoparticles. Taken together, these data support the conclusion that these motors maintain their unidirectional rotary cycle when grafted to the surface of small (ca. 2 nm) gold nanoparticles. Thus, continuous irradiation of the system under appropriate conditions leads to unidirectional rotation of the upper half of the molecules relative to the entire nanoparticle.
Proceedings of the National Academy of Sciences of the United States of America | 2002
Richard A. van Delden; Nagatoshi Koumura; Noboyuki Harada; Ben L. Feringa
Life could not exist without motion induced by a variety of molecular motors. The construction of artificial motors by chemical synthesis, which can power motions that lead to macroscopic detectable effects in a system, is a major endeavor in contemporary science. To move toward this goal, a host–guest system, composed of a nematic liquid crystal film doped with a chiral light-driven molecular motor, is assembled. Irradiation of the film results in unidirectional rotary motion of the molecular motor, which induces a motion of the mesogenic molecules leading to a molecular reorganization and, as a consequence, a change in the color of the film. In this way, by control of the rotary motion at the molecular level, color tuning over the entire visible spectrum is achieved. These findings demonstrate that a molecular motor can exert a visually observable macroscopic change in a material.
Proceedings of the National Academy of Sciences of the United States of America | 2002
Richard A. van Delden; Nagatoshi Koumura; Noboyuki Harada; Bernard Feringa
Life could not exist without motion induced by a variety of molecular motors. The construction of artificial motors by chemical synthesis, which can power motions that lead to macroscopic detectable effects in a system, is a major endeavor in contemporary science. To move toward this goal, a host–guest system, composed of a nematic liquid crystal film doped with a chiral light-driven molecular motor, is assembled. Irradiation of the film results in unidirectional rotary motion of the molecular motor, which induces a motion of the mesogenic molecules leading to a molecular reorganization and, as a consequence, a change in the color of the film. In this way, by control of the rotary motion at the molecular level, color tuning over the entire visible spectrum is achieved. These findings demonstrate that a molecular motor can exert a visually observable macroscopic change in a material.
Chemical Communications | 2002
Richard A. van Delden; Ben L. Feringa
A colour indicator for the full range of enantiomeric excess (-100%-->100% ee) is presented which is based on visual colour inspection of a liquid crystal doped with the analyte, i.e. the methyl ester of amino acid phenylglycine, providing the enantiomeric excess and allowing the assignment of the major enantiomer.
ELECTRIC PROPERTIES OF SYNTHETIC NANOSTRUCTURES: XVII International Winterschool/Euroconference on Electronic Properties of Novel Materials | 2004
Richard A. van Delden; Ben L. Feringa
Molecular motors can be defined as molecules that are able to convert any type of energy input (a fuel) into controlled motion. These systems can be categorized into linear and rotary motors, depending on the motion induced. This brief account will discuss the state of affairs of the research on light‐driven rotary molecular motors.
Collaboration
Dive into the Richard A. van Delden's collaboration.
National Institute of Advanced Industrial Science and Technology
View shared research outputs