摘要 |
The present invention provides water-soluble, pyran-based photochromic compounds characterized by improved stability when in an open, excited configuration. The advantages of the present invention are provided, at least in part, by functionalizing a pyran-based photochromic compound with carboxylate functionality in such a way that the carboxylate and/or its counter ion have sufficient mobility to engage in intermolecular and intramolecular interactions. In preferred embodiments, such a mobile carboxylate and/or counter ion provided on one side of an open pyran ring is preferably capable of complexing with functionality on the other side of the open pyran ring, greatly stabilizing the open configuration.
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