Metal-Ion Chelation and Sensing Using a Self-Assembled Molecular Photoswitch
| Autor: | David A. Russell, and Anne-Mette Nygård, Michael J. Cook, Zhenxin Wang |
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| Rok vydání: | 2003 |
| Předmět: | |
| Zdroj: | Langmuir. 19:3779-3784 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la026792n |
| Popis: | The novel (pyridylazo)phenol derivative 8-[4-(2-pyridylazo)phenoxy]octyl disulfide (1) has been designed and synthesized for the formation of a monolayer film on gold-coated optical waveguides via the technique of self-assembly. The photoinduced trans to cis isomerization of the self-assembled monolayer of 1 (1 SAM) and its interaction with transition-metal ions have been studied by spectroscopic (UV−visible and reflection absorption infrared) and electrochemical methods. The 1 SAM in the trans isomeric form provides a bidentate ligand that can chelate metal ions, such as Ni2+ and Co2+, and results in a strong absorption in the UV−visible absorption spectrum at 433 nm, a red shift of 77 nm from the maximum absorption wavelength for the unchelated 1 SAM. Following irradiation with waveguided UV light (λ = 365 nm) via the evanescent field, the 1 SAM photoisomerizes to the cis form. No metal chelation was observed with the cis isomer of the 1 SAM. The photoinduced processes are reversible; the cis form SAM i... |
| Databáze: | OpenAIRE |
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