The preparation and spectroscopic study of self-assembled monolayers of a UVsensitive spiroxazine dye on gold

The molecular orientation and structure of self-assembled monolayers on gold of a spiroxazine dye have been investigated using visible absorption and infrared spectroscopy. The absorption spectra of the photochromic spiroxazine dye in various solvents exhibited positive solvatochromism, a finding which strongly suggests that the dye structure changes to an open chain form which may be a keto type structure. A spiroxazine dye monolayer was deposited on a gold surface using a stepwise method that involved the covalent linkage of the dye to a cystamine monolayer-modified gold. The molecular structure of the self-assembled monolayer of the spiroxazine dye was investigated using Fourier-transform reflection absorption spectra.