ORGN 436 |
Digital processing with a three-state molecular switch
| Silvia Giordani1, Françisco M Raymo1, Andrew J P White2, and David J Williams2. (1) Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, (2) Department of Chemistry, Imperial College, South Kensington, London, SW7 2AY, United Kingdom |
We have identified a three-state molecular switch that responds to chemical and optical inputs producing optical outputs. We have encoded binary digits in its inputs and outputs applying positive logic conventions and demonstrated that this chemical system converts three-digit input strings into two-digit output strings. The logic function executed by the three-state molecular switch is equivalent to that of a combinational logic circuit integrating two AND, two NOT and one OR gate. The three states of the molecular switch are a colorless spiropyran, a purple trans-merocyanine and its yellow-green protonated form. We have elucidated their structures by X-ray crystallography, 1H-NMR spectroscopy, COSY and NOE experiments as well as density functional calculations. The three input stimulations controlling the interconversion of the three states of the molecular switch are ultraviolet light, visible light and H+. The two outputs are the absorption bands in the visible region of the two colored states of the molecular switch. We have monitored the switching processes and quantified the associated thermodynamic and kinetic parameters with the aid of 1H-NMR and visible absorption spectroscopies. |
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Physical Organic, Materials, Heterocycles, Aromatics, Metal-Mediated Reactions
8:00 PM-10:00 PM, Tuesday, September 9, 2003 Hilton New York -- Americas Hall 1, Poster
Division of Organic Chemistry
The 226th ACS National Meeting, New York, NY, September 7-11, 2003
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