4,4-Bis(2-ethylhexyl)-6-(9-(2-ethylhexyl)-2,3,4,4a,9,9a-hexahydro-1<i>H</i>-carbazol-6-yl)-4<i>H</i>-cyclopenta[2,1-<i>b</i>:3,4-<i>b</i>′]dithiophene-2-carbaldehyde

Abstract

Dyes with a donor–π–spacer–acceptor (D-π-A) structure containing a dicyanovinyl group as an acceptor have recently been of interest for the production of single-component organic solar cells. The most convenient precursors for their synthesis are the corresponding aldehydes. In this communication, 4,4-bis(2-ethylhexyl)-6-(9-(2-ethylhexyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazol-6-yl)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2-carbaldehyde was synthesized by the Suzuki cross-coupling reaction between 4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b′]dithiophene-2,6-dicarbaldehyde and 9-(2-ethylhexyl)-6-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole in the presence of tetrakis(triphenylphosphine)palladium(0). The structure of the newly synthesized compound was established by means of high-resolution mass spectrometry, 1H, 13C NMR, IR, and UV spectroscopy.

Keywords

• small molecules for solar cells
• building block for solar cells components
• Suzuki cross-coupling reaction
• 4<i>H</i>-cyclopenta[2,1-<i>b</i>:3,4-<i>b</i>′]dithiophene
• 2,3,4,4a,9,9a-hexahydro-1<i>H</i>-carbazole