Photophysics of a Fluorescent Probe of the Laurdan Molecule in Homogeneous and Binary Solvents

Abstract

The spectral and luminescent properties of the laurdan molecule (6-dodecanol 2-dimethylamino-naphthalene) are investigated by experimental and theoretical methods of time-dependent density functional theory (TDDFT). The fluorescence spectra of laurdan in homogeneous and binary solvents are analyzed using derivative spectroscopy method. It is shown that the fluorescence band (in hexane, cyclohexane, and triton X-100) is complex: two structures having energy difference 1000–1500 cm^–1 are manifested for the molecule. The calculated data show the non-rigidity of its structure. The effect of proton-donor solvents is considered with allowance for not only dipole-dipole interactions, but also formation of the hydrogen bond.