Oligothiophene ligands

Scheme 1.60 Test reaction with diamino-oligothiophene ligands.

In addition, highly enantioselective nitroaldol reactions were performed by Bandini et al. by using a new class of C2-symmetric oligothiophene ligands, in 2007. Thus, associated to copper, these C2-symmetric bis(amino) ligands allowed the synthesis of a wide range of enantiomerically enriched nitroalcohols... 

Scheme 10.33 Cu-catalysed Henry reactions with oligothiophene ligand.

Er111 complexes with 1 2 stoichiometries are isolated by reaction of the sodium salts of the two oligothiophene ligands with erbium chloride under anhydrous conditions. No analytical data are reported to prove this stoichiometry, but both compounds Na[Er(83a)2] and Nas [Er(83b)2] display the 1.54 pm emission in anhydrous pyridine upon excitation at 353 nm. The emission intensity of [Er(83a)2r is comparable to the fluorescence intensity of [Er(8-Q)3] recorded under the same experimental conditions, while emission intensity of the pentathiophene complex is about half that. This is explained by the more efficient triplet state production in shorter oligothiophenes than in longer ones (Destri et al., 2003). 

Multimetallic complexes are also of interest. Ru complexes (30 and 31, Chart 5.7) in which the two metals are bridged via oligothiophene ligands of varying lengths have been prepared and their electrochemical and spectroscopic behaviors characterized [44]. In these complexes, the first reduction is bpy-based and the first oxidation is thiophene-based. The metals are weakly interacting and transient absorption and photophysical studies reveal that the lowest excited state is an oligothiophene-based state. The Ru,... 

R. D. Myrex, G. M. Gray, A. G. VanEngen Spivey and C. M. Lawson, Synthesis and characterization of transition metal systems containing phosphino-oligothiophene ligands for nonlinear optical materials, Organometallics, 25, 5045-5050 (2006). 

Functionalized gold nanoparticles chemisorbed by oligothiophenes as n-ligands and their networked structures 04YGK447. 

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]. 

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