Oligothiophenes transition metal complexes

Other donors very often used in combination with fullerenes comprise ferrocene, phthalocyanine, transition metal complexes, aniline derivatives, tetrathiafulvalene and oligoacenes, carotenoids, oligoarylene, and oligothiophene and many examples are collected in recent reviews and books dedicated to this subject.3a,7e 28... 

Phosphines are extremely versatile and ubiquitous ligands in transition metal chemistry [34], They possess several attributes which make them ideal as ligands, including the ability to tune the steric and electronic properties via the choice of the three substituents on the phosphine. Several studies have incorporated phosphine functionalities into oligothiophenes and metal complexes of these ligands have been prepared and studied. A series of diphenylphosphine substituted oligothiophenes (4-11, Chart 5.3) have been prepared [35, 36]. 

Roncali et al. [277] recently synthesized some macrocyclic oxyethylene-bridged oligothiophenes 2.184 and 2.185 in which oxyethylene groups were attached to the internal -position of both terminal thiophenes via a sulfide linkage (Chart 1.38). NMR and UV-Vis spectroscopic analysis of the macrocycles in the presence of metal ions (Ba +, Sr +, Pb +) revealed the formation of 1 1 complexes and resulted in conformational transitions in the ir-conjugated system. The absorption spectra of 2.184 showed small red shifts in the presence of metal cations, whereas no change was observed for 2.185. Furthermore, the cation binding abilities of these macrocycles and their influence on the electrochemical responses were also discussed. 

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