Phototriggered NO and CN release from [Fe(CN)5NO]2− molecules electrostatically attached to TiO2 surfaces

Abstract

Phototriggered NO and CN release from [Fe(CN)₅NO]²⁻ (NP) molecular monolayers is studied by a combination of electrochemistry, infrared spectroscopy, and mass spectrometry under light irradiation at temperatures of 80 K and 294 K. The NP molecular monolayers were electrostatically attached to thin films of mesoporous TiO₂ deposited on silicon. Irradiation of the surfaces results in NO and CN release, which is verified using mass spectrometry. The kinetic trace of the light driven NO release of the [Fe(CN)₅NO]²⁻ is determined by inspection of the ν_NO stretching mode as a function of exposure to light in the violet/green spectral range. The decrease of the ν_NO-amplitude can be modeled considering the NO release as a two-step process with an intermediate state between the attached and the released state. According to literature, the intermediate state may be related to the light-induced linkage NO isomerization of the NP.