Abstract
Acidity constants (in terms of Ki values) can be fine-tuned, their values can be pushed to extremes, and their location can be placed either at the basic or acidic range of the pH scale, by tailoring intra-cage properties of SiO2 sol-gel materials with surfactants. With the entrapped "solid-state pseudomicelles", an 8-orders magnitude Ki shift - from the high-basic pH region to the acidic one - was obtained for acid fuchsin (AF); and tunability of the pKi values of the solvatochromic dye ET(30) and of crystal violet over much of the pH scale was achieved. This tailoring of various activities from the same dopant was achieved either by utilizing surfactants of different nature or by utilizing mixtures of anionic/cationic surfactants. The extraction of a wide range of reactivities from a single compound and the ability to fine-tune it is a powerful concept with potential extensions beyond acid/base reactions.
Original language | English |
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Pages (from-to) | 5730-5734 |
Number of pages | 5 |
Journal | Journal of the American Chemical Society |
Volume | 123 |
Issue number | 24 |
DOIs | |
State | Published - 2001 |