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MSC Colloquium M.A. Rampi


12 January 2006 FWN-Building 5111.0080, Nijenborgh 4, 9747 AG, Groningen
M.A. Rampi
M.A. Rampi
Speaker: M.A. Rampi
Affiliation: Dipartmento di Chimica, Università di Ferrara, Ferrara, Italy
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, USA
Title: Gating current flowing through molecules
Date: Thu Jan 12, 2006
Start: 16.00 (Doors open and coffee available at 15.30)
Location: FWN-Building 5111.0080


The control of the current flowing through metal-molecule(s)-metal junctions is relevant for testing theories of electron transport and for designing electronic devices.  Among a variety of junctions based on different design, junctions based on Hg electrodes, show a large versatility in incorporating molecules of different complexity organized in self assembled  monolayers (SAMs). These junctions have been used i) to  correlate electron transfer rate and chemical structure, 1, 2  to gate the current by external triggers.
Photochromic units, that undergo reversible photoisomerization have been incorporated in  junctions that allow for irradiation through a transparent gold electrode.  The intensity of the current flowing between the electrodes changes of order of magnitudes under irradiation. The current can be reversibly photogated.3,4  
Redox sites with low lying redox states have been incorporated in electrochemical junctions between two Hg electrodes.  By connecting the electrodes to a  bipotentiostat is possible to control the potential applied to the electrodes respect to the electrochemical potential of redox sites.  These systems allow to control and to predict the NDR (negative differential resistance) values by controlling the electron transfer mechanisms.  These junctions show the characteristics of solid state transistors. 5

1. M. Duati, C. Grave, N. Tcbeborateva, J. Wu, K. Müllen, A. Shaporenko, M. Zharnikov, J. K. Kriebel, G. M. Whitesides and M. A. Rampi* Adv. Mat. 2005. in press
2. F. Milani, C. Grave, V. Ferri, Maria Anita Rampi* Submitted
3. Duati, M. Cattabriga, M.; Belser, P.; Zharnikov, M.; Rampi, M.A. Manuscript in preparation.
4. M.Cattabriga, M. Duati, S. Carli, V. Ferri, V. Adamo, P. Belser, and  M. A. Rampi, Submitted
5. Tran, E.;. Rampi*, M.A.; Whitesides*, G.M. Angew. Chem. Int. Engl. Ed. 2004, 43, 3835

Last modified:22 October 2012 2.30 p.m.