Synthesis and X-ray single-crystal structure study of 5,5′-bis(silyl)-functionalized 3,3′-dibromo-2,2′-dithiophenes

Abstract

A high-yield synthesis toward 5,5 -bis(silyl)-functionalized 3,3 -dibromo-2,2 -dithiophenes with very efficient work-up procedure is presented. The molecular structures of two silyl functionalized dibromo-dithiophenes in the solid state have been determined to investigate the structural influences of different functional groups on the degree of π -conjugation within the dithiophene moieties, as well as their packing properties. The planar alignment of the tert-butyldimethylsilyl-functionalized dibromo-dithiophene shows a significantly higher degree of conjugation of the π -system with a more favorable molecular packing than the skewed arrangement of the triisopropylsilyl-substituted species.

Structure–Property Studies of Bichromophoric, PAH-Functionalized Dithieno[3,2-b:2′,3′-d]phospholes

“…Unless noted otherwise, starting materials were used as received or distilled prior to use. Bis(diethylamino)chlorophosphane, 3,3′-dibromo-2,2′-dithiophene ( 1a ), 3,3′-dibromo-5,5′-bis(trimethylsilyl)-2,2′-dithiophene ( 1b ), and 3,3′-dibromo-5,5′-bis( tert -butyldimethylsilyl)-2,2′-dithiophene ( 1c ) were prepared according to literature procedures. 31 P{ 1 H} NMR, 1 H NMR, and 13 C{ 1 H} NMR were recorded on Bruker DRX400 and Avance (-II,-III) 400 MHz spectrometers.…”

Synthesis and Unexpected Reactivity of Si−H Functionalized Dithieno[3,2-b:2‘,3‘-d]phospholes

“…The Si−H functionalized dithienophosphole 2 is accessible in good yield (76%) via a similar protocol as reported for other silylated dithienophospholes . Reaction of 5,5‘-bis(dimethylsilyl)-3,3‘-dibromo-2,2‘-dithiophene 1 with n -BuLi in the presence of TMEDA in Et 2 O at −78 °C affords the product 2 after addition of phenyl(dichloro)phosphane (Scheme ). The 31 P NMR spectrum of 2 shows a resonance at δ −24.1 ppm that is slightly downfield shifted compared to other related silyl-functionalized dithienophospholes (δ 31 P −25.0 to −28.2 ppm) 4a.…”

A Novel Amine-Free Dianchoring Organic Dye for Efficient Dye-Sensitized Solar Cells

“…We established a modified approach for synthesizing spiro-bridged bithiophene, which avoids the use of reported cyclopenta[2,1- b :3′,4′- b ′]dithiophen-4-one as the essential intermediate. Our synthesis started from the selective lithium-bromo exchange reaction of 3,3′,5,5′-tetrabromo-2,2′-bithiophene with n -BuLi, followed by quenching with chlorotriisopropylsilane (TIPS-Cl) to give TIPS-capped bithiophene 1 (46%) . For the subsequent cyclization reaction, the introduction of TIPS groups on the reactive α-position of thiophene is essential for preventing possible intermolecular reactions.…”