Germanium and Tin in Conjugated Organic Materials

Synthesis of Pyridinothienogermoles as Unsymmetrically Condensed Germoles

“…Group 14 metalloles, such as siloles and germoles, have received attention as core structures of conjugated functional materials. , The often-observed interaction between Si/Ge σ*-orbitals and endocyclic butadiene π*-orbitals (σ*−π* conjugation) stabilizes the lowest unoccupied molecular orbital (LUMO), resulting in enhanced electron affinity and reduced highest occupied molecular orbital (HOMO)–LUMO energy gaps . These siloles and germoles have been studied as core fragments of conjugated functional materials as Tamao and co-workers demonstrated the utility of siloles as electron-transporting materials for multilayered organic light-emitting diodes (OLEDs) .…”

“…These siloles and germoles have been studied as core fragments of conjugated functional materials as Tamao and co-workers demonstrated the utility of siloles as electron-transporting materials for multilayered organic light-emitting diodes (OLEDs) . The condensation of siloles and germoles with heterobiaryls has also been studied in an effort to manipulate their properties and thus tune their functionalities . Of those, dithienosilole (DTS) and dithienogermole (DTG) (Chart ) are currently utilized as building units of conjugated functional materials for optoelectronic devices, such as OLEDs, organic transistors, and organic photovoltaic cells. , It has also been demonstrated that condensed tricyclic systems could be used as highly luminescent materials and sensors.…”

Covalent triflates as synthons for silolyl- and germolyl cations

“…Sila-and germacyclopentadienes 1 (siloles and germoles) found widespread interest due to their favorable photophysical properties. [1][2][3][4] Cross hyperconjugation between the ER 2 group and the butadiene part of the heterocycle results in a substantial lowering of the LUMO and an increase of the electron affinity of the group 14 heteroles (tetroles). [5][6][7][8] In addition, the discovery of the aggregation induced emission (AIE) effect of aryl-substituted siloles by Tang and coworker provided a new impetus to this field and had significant impact on materials chemistry.…”

Optical and Photosensitizing Properties of Spiro(dipyridinogermole)(dithienogermole)s with Eletron‐Donating Amino and Electron‐Withdrawing Pyridinothiadiazole Substituents

“…Similar structure‐dependent PL efficiency was found for previously reported sDPyDTG compounds 1–3 , as described above. It is also noted that the Ge σ* orbital contributes to the LUMOs and the LUMOs+1 of 5 and 6 to some extent, as is often observed for germole systems ,,,,. However, for 4’ , the LUMO with the character of DTG‐based π* orbital has limited contribution of the Ge σ* orbital, although the LUMO+3 located on the DPyG unit shows clear σ*‐π* interaction.…”