Biomedical subjects

J O Jeppesen

Publications and source records attributed to J O Jeppesen.

3 recordsLinked to original sources

PubMed2001

Molecular-based electronically switchable tunnel junction devices.

Solid-state tunnel junction devices were fabricated from Langmuir Blodgett molecular monolayers of a bistable [2]catenane, a bistable [2]pseudorotaxane, and a single-station [2]rotaxane. All devices exhibited a (noncapacitive) hysteretic current-voltage response that switched the device between high- and low-conductivity states, although control devices exhibited no such response. Correlations between the structure and solution-phase dynamics of the molecular and supramolecular systems, the crystallographic domain structure of the monolayer film, and the room-temperature device performance characteristics are reported.

Journal Article↗

PubMed2001

Binding studies between tetrathiafulvalene derivatives and cyclobis(paraquat-p-phenylene).

The complexation between a number of different pi-electron donating TTF derivatives and the pi-electron accepting tetracationic cyclophane cyclobis(paraquat-p-phenylene) (CBPQT(4+)) has been studied by (1)H NMR and UV-vis spectroscopy. The results demonstrate that the strength of association between the donors (TTF derivatives) and acceptor (CBPQT(4+)) is strongly dependent on the pi-electron donating properties (measured by the first redox potential ) of the TTF derivatives. However, the first redox potential () is not the only factor of importance. The extended pi-surface of the TTF derivatives also exerts a stabilizing influence upon complexation. The kinetics for the complexation-decomplexation were studied using (1)H NMR spectroscopy and are related to the bulkiness of the TTF derivatives. These effects may serve to improve the design of interlocked molecular systems, especially (bistable) molecular switches, in which CBPQT(4+) and a derivatized TTF unit are incorporated.

Journal Article↗

PubMed2001

Switching devices based on interlocked molecules.

An architectural rationale and an experimental program aimed at the development of molecular electronics switching devices for memory and computing applications are discussed. Two-terminal molecular switch tunnel junctions are identified as the critical device components of molecular electronics-based circuitry. They can be tiled in two dimensions and are tolerant of manufacturing defects. Singly and multiply configurable solid-state switching devices that are based upon electrochemically switchable molecular and supramolecular systems are discussed in terms of both the synthesis of the molecular components and the fabrication and performance of the devices.

Electrochemistry↗