Thiophene dendrimers

In the decade since then, the major focus has been twofold improving the scope of such reactions and application of the cross-coupling reactions for the synthesis of thiophene dendrimers, thiophene polymers, and thiophenes as optoelectronic materials. 

Mitchell, W.J., N. Kopidakis, G. Rumbles, D.S. Ginley, and S.E. Shaheen. 2005. The synthesis and properties of solution processable phenyl cored thiophene dendrimers. J Mater Chem 15 4518-4528. 

A nanostructure of PT dendrimers has been synthesized and characterized with their unique supramolecular assembly into 2-D crystals, nanowires, and nanoparticle aggregates [346]. It was elucidated that self-organization of the dendrimers on the sohd substrate was dependent on the nature of the substrates, preparation methods, and the molecule-molecule and molecule-substrate interactions. It was remarkable that the PT dendrimer exhibited different nanostructures depending on the property of substrate surface. The results demonstrated the unique potential of thiophene dendrimers to form nanostructures on substrate surfaces. 

Figure 1.8 STM topographic image of a self-assembled hexagonal structure of 5.76 on HOPC. The unit cell dimensions are a = b = 10 2 nm, a = 62 2°. Reproduced with permission from C. Xia, X. Tan, J. Locklin, R. C. Advincula, A. Cies and W. Nonidez, Characterization, supramolecular assembly and nanostructures of thiophene dendrimers, J. Am. Chem. Soc., 126, 8735-8743 (2004). Copyright 2004 American Chemical Society...

N. Kopidakis, W. J. Mitchell, J. Van de Lagemaat, D. S. Ginley, G. Rumbles, S. E. Shaheen and W. L. Ranee, Bulk heterojunction organic photovoltaic devices based on phenyl-cored thiophene dendrimers, Appl. Phys. Lett.,... 

Wong WWH, Ma CQ, Pisula W, Yan C, Feng X, Jones DJ, Mullen K, Jansstai RAJ, Bauerle P, Holmes AB (2010) Self-assembling thiophene dendrimers with a... 

Xia C, Fan X, Locklin J, Advincula RC, Gies A, Nonidez W (2004) Characterization, supramolecular assembly, and nanostructures of thiophene dendrimers. J Am Chem Soc 126 8735-8743... 

Finally, novel thiophene-containing dendrimeric materials have been prepared <00CC507, 00CM2372,00JCS(P2)1976> including Q-symmetric dendrimer 160 <00AM668>. 

The synthesis of well-defined LCB polymers have progressed considerably beyond the original star polymers prepared by anionic polymerization between 1970 and 1980. Characterization of these new polymers has often been limited to NMR and SEC analysis. The physical properties of these polymers in dilute solution and in the bulk merit attention, especially in the case of completely new architectures such as the dendritic polymers. Many other branched polymers have been prepared, e.g. rigid polymers like nylon [123], polyimide [124] poly(aspartite) [125] and branched poly(thiophene) [126], There seems to be ample room for further development via the use of dendrimers and hyperbran-... 

The third-generation dendrimer palladium complex (31, containing 24 PdC groups) was applied in the Stille coupling of methyl-2-iodobenzoate with 2-(tributyl-stannyl)thiophene in DMF (Scheme 10 lmol% catalyst). In contrast to what was observed with the monomer (PPh3)2PdCl2, no palladium metal formation was... 

Some dendrimers (389-391) have been reported. The thiophene-containing dendrimers are promising materials, due to the unique properties of oligothiophenes and their derivatives, such as high charge carrier mobility, efficient fluorescence, excellent stability in ambient conditions (even at elevated temperatures), and easy functionalization. 

Other dendrimers, such as 414, were obtained from the same thiophene scaffold (05JA373) this compound showed an absorption band at 490 nm and an emission centered at 600 nm. 

Fig. 4.44 Carbosilane dendrimer assembled from thiophene building blocks (according to Nakayama et al.)...

A first-generation carbosilane dendrimer consisting of 16 thiophene rings could be isolated in 19% yield, albeit together with various by-products in comparable amounts [85]. The synthetic building block methyl tris(2-thienyl)silyl ether was first prepared from tetramethoxysilane and an excess of thienyl-lithium (Fig. 4.44). 

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