Cationic Molecular Rulers: Synthesis, Characterization, and Intramolecular Complications
| Autor: | William H. Steel, Robert A. Walker, Carmen L. Beildeck |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
chemistry.chemical_classification
Aqueous solution Cyclohexane Chemistry Solvatochromism Cationic polymerization Surfaces and Interfaces Chromophore Condensed Matter Physics Photochemistry chemistry.chemical_compound Phase (matter) Intramolecular force Electrochemistry General Materials Science Spectroscopy Alkyl |
| Zdroj: | Langmuir. 19:4933-4939 |
| ISSN: | 1520-5827 0743-7463 |
| DOI: | 10.1021/la0343122 |
| Popis: | A new family of cationic, solvent-sensitive surfactants is synthesized and characterized. The surfactants consist of a solvatochromic, hydrophobic chromophore connected to a quaternized ammonium headgroup by short alkyl spacers of varying lengths. The chromophore is based on p-nitroanisole (pNAs), a simple aromatic probe whose first electronic excitation wavelength shifts more than 20 nm as the local dielectric environment varies between nonpolar and polar limits. Given that pNAs is 20 times more soluble in cyclohexane than in water, lengthening the separation between the chromophore and the charged headgroup enables the chromophore to extend further into the organic phase when surfactants adsorb to an aqueous/organic interface. Thus, in principle, these surfactants can function as molecular rulers by measuring the distance required for solvent polarity to converge from an aqueous to an organic limit across different liquid/liquid boundaries. Preliminary resonance-enhanced second harmonic generation spect... |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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