Perylenediimide (PDI)‐based self‐assembled monolayers (SAMs) have been studied by using quartz crystal microbalance, X‐ray photoelectron spectroscopy, cyclic voltammetry, and spectroelectrochemistry (SEC). The high stability of PDI‐based SAMs has allowed very low signals to be probed by using absorption and emission SEC and by extracting voltabsorptograms. The wavelengths are reported for the absorption maxima of the PDI, anion radical, and dianion species. In contrast, the magnitudes of the molar extinction coefficient of the reduced forms were not preserved in the SAM. The quenching of PDI fluorescence was confirmed on a gold substrate.

The study of mixed self‐assembled monolayers of perylenediimide and hexanethiol by cyclic voltammetry and absorption spectroelectrochemistry shows a non‐linearity of absorbance maxima as a function of the surface coverage. This surprising result could be supported by an increase in the average tilt angle at low coverage, suggesting that the dilution of redox species through an alkanethiol would induce a change of the orientation of immobilized chromophores and, therefore, a modification of the optical properties of the monolayer.

The electrochemical and spectroelectrochemical studies of thienylene vinylene (TV) derivatives in the immobilized state are compared with the ones obtained in solution. The results highlight the exaltation of the dimerization process onto TV-based self-assembled monolayers, in which the π interaction is maintained even after 75% dilution.