Pyrene chromophores, SAMs

Pyrene is one of the most prominent standard chromophores for probing fluorescence in relation to excimer formation [186]. Fox and Whitesell et al. used a tripodal anchor group to attach a pyrene chromophore in a stable and well-ordered monolayer (Fig. 29,19) [122,187]. Although attached to a conducting surface, these monolayers display significant fluorescence from a pyrene excited state. The SAMs obtained are so stable that extensive washing did not result in any loss of fluorescence intensity. 

Fig. 29 SAMs containing pyrene chromophores 19 pyrene bound to the gold surface via a tripodal anchor group [122,187] 20 mixed SAM of pyrene and porphyrin [27,147] 21 multilayer system consisting of pyrene and Cu(ll)-complexes [188]...

The ET and EN processes in chromophore SAMs have been widely studied with different systems such as porphyrins [142,149,150,160,161], fuller-enes [28,177-179], carbazols [118], pyrenes [147] and dyads or triads containing these units [26,27,117,189,191]. 

Besides the porphyrins, fuUerenes, aromatic azo-compoimds and pyrenes widely used as chromophores in SAMs there are some rarely used tt-systems, which are mentioned in this section. 

Karpovich and Blanchard used 1-pyrenebutanethiol as a fluorescence chromophore embedded in a SAM of octadecanethiol in order to probe the dynamical behaviour. The dilution (3% pyrene) leads to non-aggregate pyrene emission at 400 nm. The fluorescence decay is non-exponential with... 

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