Laurdan solvatochromism: influence of solvent polarity and hydrogen bonds

Abstract

Laurdan solvatochromism is generally exploited in biological studies, but some of its properties are not completely elucidated. Two of them are related to the dipole moment of Laurdan and its possibility to form hydrogen bonds. Using solvatochromic methods we determined the Laurdan dipole moments both in the ground and excited states. Using different solvent polarity scales we observed that in the excited state aside from the effect of solvent polarity, a specific solvent effect appears. We showed that this specific effect is caused by hydrogen bonds formed between Laurdan and polar protic solvents.