Absorption Spectroelectrochemistry on Mixed Perylenediimide‐Based Self‐Assembled Monolayers: Non‐Linear Dependence of Absorbance versus Surface Coverage

Abstract

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.

Real-time absorption spectroelectrochemistry: From solution to monolayer

“…In other words, the more the surface coverage increases, the more the absorbance deviates from Beer's law, which has been interpreted (but still not confirmed so far) by a surface coverage dependence of the tilt angle of PDI moieties, inducing a direction change of dipolar moments. [28] Decreasing The grafting impact on the photoluminescence of PDI moieties has also been studied by E-SEC and, as expected, no light emission was detected because of a quenching of molecular fluorescence on Au substrate via an energy transfer (i.e. Förster resonance energy transfer).…”

“…see reference [39]) within redox-responsive materials (e.g. see reference [40]) or in surface-confined redox species [27,28,35,37] and it should facilitate the establishment of detailed structureproperties and structure-reactivity relationships at nanoscale. Lastly, it is important to bear in mind that a fine study of current-voltage characteristics, supported, where possible, by efficient electrochemical simulations (e.g.…”

From Monolayer to Multilayer: Perylenediimide Diazonium Derivative Acting Either as a Growth Inhibitor or a Growth Enhancer

“…In both cases, the peak-to-peak separation is ca. 80 mV, indicating the fast electron transfer typical for PDI derivatives. , …”

“…The experiments were performed in a glovebox. The dotted lines indicate the positions of bands attributed to the conversion of PDI 0 to PDI – and PDI 2– . ,, …”

“…80 mV, indicating the fast electron transfer typical for PDI derivatives. 25,26 The shape of voltammogram changes when the formation of dC12PDI is initiated by addition of tBuONO in the solution of aC12PDI (Fig. 2b).…”