Terrylene diimides

The steady state absorption and fluorescence spectra of both dendrimer generations 1 and 2 are depicted in Fig. 2. The former are merely superpositions of the absorption spectra of both chromophores involved. In the fluorescence, however, the peryleneimide part is almost completely quenched compared to the model compound. Instead, the fluorescence at wavelengths longer than 650 nm almost completely resembles the emission spectrum of the terrylene-diimide model compound 3. This feature is a strong indication that within these dendrimers the excitation energy is efficiently transferred from the peryleneimide to the terrylenediimide. 

Scheme 13.20 Synthesis of quaterrylene and terrylene diimides 70 and 74, respectively.

In 2004, the first work was reported directed toward single-pair electronic EET in a dyad built from perylene diimide (PDl) as donor, terrylene diimide (TDl) as acceptor and a p-terphenyl spacer (dyad 1, Pig. 1) as bridging group [1]. Since then, several more single-molecule as well as computational studies on this compound have been carried out to investigate the prevailing energy transfer... 

Finally, the open form of the dyad (dyad 1-a) was synthesized by Suzuki coupling of the PDI part 6a and the TDI part 13 (Scheme 2, step g). The dyad 1-a was obtained in 60% yield after gel permeation chromatography (GPC). Due to its extended aromatic core, terrylene diimide shows a much lower solubility than its smaller homologue perylene diimide. Concerning the poor solubility of the TDI unit, the cyclization reaction was performed as the last step (Scheme 2, step h). As shown in Fig. 2, the perylene part is susceptible to hydrolysis, so the cyclization had to be performed rapidly (within 30 min). Cyclization using K2CO3 as base in ethanolamine completed the synthesis of the dyad 1. Besides imreacted 1-a, the... 

Figure 15 gives an example of the fiuorescence decay time trajeaory and the corresponding autocorrelation curve, experimentally obtained for a single terrylene diimide dye molecule embedded in a thin PS film. By fitting the decay curve, a relaxation time of 22 s could be obtained. 

Figure 13.3 Chemical structures of rylene diimides (perylene, n = 0 terrylene, n = 1 quaterrylene, n = 2 pentary-lene, n = 3 hexarylene, n = 4).

Lee SK, Zu Y, Herrmann A, Geerts Y, MAllen K, Bard AJ (1999) Electrochemistry, spectroscopy and electrogenerated chemiluminescence of petylene, terrylene, and quaterrylene diimides in aprotic solution. J Am Chem Soc 121(14) 3513-3520... 

Mullen and co-workers extended the synthesis of perylene discotics to various other core-enlarged perylene dyes, such as terrylene and quaterrylene diimides [158]. An example of quaterrylene diimides synthesis is shown in Scheme 4.24. 

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