Synthesis, Optical Properties, and Crystal Structures of Dithienostannoles

Reactions of dichlorodiphenylstannane with 3,3′-dilithio-5,5′-bis­(trimethylsilyl)-2,2′-bithiophene and 3,3′-dilithio-2,2′-di­(benzo­[<i>b</i>]­thiophene) gave 1,1-diphenyl-3,6-bis­(trimethylsilyl)­dithienostannole (<b>DTSn1</b>) and di­(benzo­[<i>b</i>]­thieno)-1,1-diphenylstannole (<b>DTSn2</b>), respectively. Optical properties of the dithienostannoles and the results of DFT calculations on a model suggested an in-phase interaction between Sn σ* and bithiophene π* orbitals, stabilizing the LUMO. Interestingly, <b>DTSn1</b> showed crystallization-enhanced emission and the photoluminescence (PL) quantum yield of the crystals was determined to be higher by about 20 times than that in the amorphous and solution phase, while <b>DTSn2</b> exhibited moderate PL efficiency both as crystals and in solution. Crystal structures of the dithienostannoles were determined by X-ray diffraction studies, which showed the differences in the molecular packing between <b>DTSn1</b> and <b>DTSn2</b>, being responsible for their different PL properties in the crystal state

Synthesis of Group 14 Dipyridinometalloles with Enhanced Electron-Deficient Properties and Solid-State Phosphorescence

Silicon- and germanium-bridged bipyridyls were prepared, and their optical and electrochemical properties were investigated. It was found that they exhibited enhanced electron deficiency and phosphorescence properties in comparison to parent bipyridyl. The single-crystal structure of a dipyridinosilole and results of DFT calculations on models are also described