Search

Your search keyword '"Grill L"' showing total 3 results
Start Over Author "Grill L" Topic nanotechnology
3 results on '"Grill L"'

1. Nano-architectures by covalent assembly of molecular building blocks.

Author

Grill L, Dyer M, Lafferentz L, Persson M, Peters MV, and Hecht S

Subjects
Chemistry methods, Macromolecular Substances chemistry, Materials Testing, Molecular Conformation, Particle Size, Surface Properties, Crystallization methods, Gold chemistry, Nanostructures chemistry, Nanostructures ultrastructure, Nanotechnology methods, Porphyrins chemistry
Abstract

The construction of electronic devices from single molecular building blocks, which possess certain functions such as switching or rectifying and are connected by atomic-scale wires on a supporting surface, is an essential goal of molecular electronics. A key challenge is the controlled assembly of molecules into desired architectures by strong, that is, covalent, intermolecular connections, enabling efficient electron transport between the molecules and providing high stability. However, no molecular networks on surfaces 'locked' by covalent interactions have been reported so far. Here, we show that such covalently bound molecular nanostructures can be formed on a gold surface upon thermal activation of porphyrin building blocks and their subsequent chemical reaction at predefined connection points. We demonstrate that the topology of these nanostructures can be precisely engineered by controlling the chemical structure of the building blocks. Our results represent a versatile route for future bottom-up construction of sophisticated electronic circuits and devices, based on individual functionalized molecules.

Published
2007
Full Text
View/download PDF

2. Controlling on-surface polymerization by hierarchical and substrate-directed growth.

Author

Lafferentz, L., Eberhardt, V., Dri, C., Africh, C., Comelli, G., Esch, F., Hecht, S., and Grill, L.

Subjects
POLYMERIZATION, NANOTECHNOLOGY, MOLECULAR electronics, HALOGEN compounds, COVALENT bonds, POLYMERASE chain reaction, SCANNING tunneling microscopy, PORPHYRIN synthesis
Abstract

A key challenge in the field of nanotechnology, in particular in the design of molecular machines, novel materials or molecular electronics, is the bottom-up construction of covalently bound molecular architectures in a well-defined arrangement. To date, only rather simple structures have been obtained because of the limitation of one-step connection processes. Indeed, for the formation of sophisticated structures, step-by-step connection of molecules is required. Here, we present a strategy for the covalent connection of molecules in a hierarchical manner by the selective and sequential activation of specific sites, thereby generating species with a programmed reactivity. This approach leads to improved network quality and enables the fabrication of heterogeneous architectures with high selectivity. Furthermore, substrate-directed growth and a preferred orientation of the molecular nanostructures are achieved on an anisotropic surface. The demonstrated control over reactivity and diffusion during covalent bond formation constitutes a promising route towards the creation of sophisticated multi-component molecular nanostructures. [ABSTRACT FROM AUTHOR]

Published
2012
Full Text
View/download PDF

3. Spatial periodicity in molecular switching

Author

Stefan Hecht, Carlo Dri, Maike V. Peters, Jutta Schwarz, Leonhard Grill, Dri, Carlo, Peters, M. V., Schwarz, J., Hecht, S., and Grill, L.

Subjects
Microchip Analytical Procedures: methods, Molecular Conformation, Butanes: chemistry, chemistry [Butanes], Azo Compounds: chemical synthesis, SELF-ASSEMBLED MONOLAYERS, Models, Microscopy, Scanning Tunneling, Lab-On-A-Chip Devices, Electrochemistry, Nanobiotechnology, Nanotechnology, General Materials Science, AZOBENZENE, Nanotechnology: methods, ISOMERIZATION, Molecular switch, Microscopy, method [Electrochemistry], Physicist, Condensed Matter Physics, Atomic and Molecular Physics, and Optics, Electrochemistry: methods, instrumentation [Microchip Analytical Procedures], Homogeneous, Chemical physics, Azo Compounds, Azo Compounds: chemistry, Butanes, Energy Transfer, Isomerism, Microchip Analytical Procedures, Microchip Analytical Procedures: instrumentation, Scanning Tunneling, Chemical, Surface Properties, Layer (electronics), Butane, method [Nanotechnology], Materials science, Biomedical Engineering, chemical synthesi [Azo Compounds], Microchip Analytical Procedure, Bioengineering, Molecular nanotechnology, Azo Compound, Molecule, Electrical and Electronic Engineering, method [Microchip Analytical Procedures], business.industry, SCANNING-TUNNELING-MICROSCOPY, chemistry [Azo Compounds], Models, Chemical, AU(111) SURFACE, Photonics, business, Model
Abstract

The ultimate miniaturization of future devices will require the use of functional molecules at the nanoscale and their integration into larger architectures(1,2). Switches represent a prototype of such functional molecules because they exhibit characteristic states of different physical/chemical properties, which can be addressed reversibly(3). Recently, various switching entities have been studied and switching of single molecules on surfaces has been demonstrated(4-13). However, for functional molecules to be used in a future device, it will be necessary to selectively address individual molecules, preferentially in an ordered pattern. Here, we show that azobenzene derivatives in the trans form, adsorbed in a homogeneous two-dimensional layer, can be collectively switched with spatial selectivity, thus forming a periodic pattern of cis isomers. We find that the probability of a molecule switching is not equally distributed, but is strongly dependent on both the surrounding molecules and the supporting surface, which precisely determine the switching capability of each individual molecule. Consequently, exactly the same lattices of cis isomers are created in repeated erasing and reswitching cycles. Our results demonstrate a conceptually new approach to spatially addressing single functional molecules.

Published
2008

Catalog

Books, media, physical & digital resources
See catalog results