Cyclotrimeric terthiophenediacetylene

Figure 2.17. Synthesis of cyclotrimeric terthiophenediacetylene and of the fully O -conjugated cyclo[12]thiophene (Kromer et al, 2000).

To hnish this section and chapter we will briefly discuss the synthetic routes pursued in order to obtain cyclothiophenes, fully a-conjugated macrocyclic oligothiophenes, i.e., joining boths ends of linear a-thiophenes (Kromer et al., 2000). One advantage of these macromolecules is that the mean diameter of the cavity can be tuned by selecting the initial building blocks. In Section 4.2 we will explore how such molecules, in particular cyclotrimeric terthiophenediacetylene, self-assemble on a surface. 

Let us first explore the selected STM example concerning the molecular system cyclotrimeric terthiophenediacetylene shown in Fig. 4.11 (Mena-Osteritz Bauerle, 2001). The synthesis of this molecule was discussed in Section 2.5 (Fig. 2.17). When a solution of the cyclotrimeric terthiophenediacetylene macrocycle in C6H3CI3 is brought onto a freshly cleaved HOPG substrate, spontaneous formation of a SAM is found with honeycomb ordering at the solution/HOPG interface. 

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