Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Más filtros

Banco de datos
Tipo de estudio
Tipo del documento
Asunto de la revista
Intervalo de año de publicación
1.
Molecules ; 27(23)2022 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-36500413

RESUMEN

Self-assembled monolayers (SAMs) of terpyridine-based transition metal (ruthenium and osmium) complexes, anchored to gold substrate via tripodal anchoring groups, have been investigated as possible redox switching elements for molecular electronics. An electrochemical study was complemented by atomic force microscopy (AFM) and scanning tunneling microscopy (STM) methods. STM was used for determination of the SAM conductance values, and computation of the attenuation factor ß from tunneling current-distance curves. We have shown that SAMs of Os-tripod molecules contain larger adlayer structures compared with SAMs of Ru-tripod molecules, which are characterized by a large number of almost evenly distributed small islands. Furthermore, upon cyclic voltammetric experimentation, Os-tripod films rearrange to form a smaller number of even larger islands, reminiscent of the Ostwald ripening process. Os-tripod SAMs displayed a higher surface concentration of molecules and lower conductance compared with Ru-tripod SAMs. The attenuation factor of Os-tripod films changed dramatically, upon electrochemical cycling, to a higher value. These observations are in accordance with previously reported electron transfer kinetics studies.


Asunto(s)
Oro , Microscopía de Túnel de Rastreo , Microscopía de Fuerza Atómica , Propiedades de Superficie , Oro/química , Oxidación-Reducción
2.
Angew Chem Int Ed Engl ; 60(9): 4732-4739, 2021 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-33205862

RESUMEN

Environmental control of single-molecule junction evolution and conductance was demonstrated for expanded pyridinium molecules by scanning tunneling microscopy break junction method and interpreted by quantum transport calculations including solvent molecules explicitly. Fully extended and highly conducting molecular junctions prevail in water environment as opposed to short and less conducting junctions formed in non-solvating mesitylene. A theoretical approach correctly models single-molecule conductance values considering the experimental junction length. Most pronounced difference in the molecular junction formation and conductance was identified for a molecule with the highest stabilization energy on the gold substrate confirming the importance of molecule-electrode interactions. Presented concept of tuning conductance through molecule-electrode interactions in the solvent-driven junctions can be used in the development of new molecular electronic devices.

3.
Electrochim Acta ; 360: 136984, 2020 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-32863402

RESUMEN

The combination of computer assisted design and 3D printing has recently enabled fast and inexpensive manufacture of customized 'reactionware' for broad range of electrochemical applications. In this work bi-material fused deposition modeling 3D printing is utilized to construct an integrated platform based on a polyamide electrochemical cell and electrodes manufactured from a polylactic acid-carbon nanotube conductive composite. The cell contains separated compartments for the reference and counter electrode and enables reactants to be introduced and inspected under oxygen-free conditions. The developed platform was employed in a study investigating the electrochemical oxidation of aqueous hydrazine coupled to its bulk reaction with carbon dioxide. The analysis of cyclic voltammograms obtained in reaction mixtures with systematically varied composition confirmed that the reaction between hydrazine and carbon dioxide follows 1/1 stoichiometry and the corresponding equilibrium constant amounts to (2.8 ± 0.6) × 103. Experimental characteristics were verified by results of numerical simulations based on the finite-element-method.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA