2.5- Diarylsiloles

M. Uchida, T. Izumizawa, T. Nakano, S. Yamaguchi, K. Tamao, and K. Furukawa, Structural optimization of 2,5-diarylsiloles as excellent electron-transporting materials for organic electroluminescent devices, Chem. Mater., 13 2680-2683 (2001). 

V. SILOLE-BASED -CONJUGATED OLIGOMERS AND POLYMERS A. 2,5-Diarylsilole Derivatives Structure-Properties Correlation... 

This section is concerned with the structure-properties relationships of 2,5-diarylsiloles and related compounds, including the substituent effects of 2,5-aryl groups, 3,4-substituents and 1,1-substituents on the silole rings. This fundamental study provides valuable information for the molecular design of new silole materials applicable to organic electronic devices. 

FIGURE 13. The first oxidation potentials ( pai) and the first reduction potentials ( pci) for 2,5 diarylsiloles. Reproduced by permission of Wiley-VCH from Reference 43... 

FIGURE 21. Emission wavelengths of organic EL devices using 2,5-diarylsiloles as emissive electron-transporting materials Cell configuration ITO/TPD/2,5-diarylsilole/Mg Ag. Reproduced by permission of the Royal Society of Chemistry from Reference 6b... 

Keywords Siloles / -Conjugated Compounds / Organic Light-Emitting Diodes/ 2,5-Diarylsiloles... 

This procedure can be applied to the synthesis of a number of silole-containing n-conjugated compounds [2], Inter alia, the combination of the present cyclization with the Pd(0)-catalyzed crosscoupling reaction enables us to prepare a series of 2,5-diarylsiloles 6 in a one-pot manner from the diethynylsilanes (Scheme 2) [9,11],... 

Thus, the intramolecular reductive cyclization of diethynylsilane, followed by quenching with the remaining lithium naphthalenide with a bulky chlorosilane and transmetalation with ZnCl2(tmen) (tmen = MAf.JVW -tetramethylethylenediamine), affords 2,5-dizinc silole 5, which is subsequently treated with the appropriate aryl bromides in the presence of a Pd catalyst to give the corresponding 2,5-diarylsiloles 6 in high yields. 

Diarylsiloles can also be applied as efficient emissive materials and the wavelengths of their luminescence are widely tunable by changing the 2,5-aryl groups, as shown in Fig. 2. 

Fig. 2. Emission wavelengths of organic LEDs using 2,5-diarylsiloles as emissive electron-transporting materials.

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