Characteristics of Aggregation Induced Emission in 1,1-Dimethyl-2,3,4,5-tetraphenyl and 1,1,2,3,4,5-Hexaphenyl Siloles and Germoles
Journal of Inorganic and Organometallic Polymers and Materials
luminescence, silole, germole, metallole, aggregation induced emission
Photoluminescence (PL) characteristics of 1,1-dimethyl-2,3,4,5-tetraphenylsilole, including its unusual and dramatic aggregation-induced emission (AIE), are described and compared to those of 1,1-dimethyl-2,3,4,5-tetraphenylgermole and 1,1,2,3,4,5-hexaphenylgermole. Although the germoles display more efficient PL emission in solution than their silole analogs when molecularly dissolved, the siloles experience a much greater enhancement of luminescence when aggregated. Silole emission is enhanced by over two orders of magnitude in the aggregated state, while aggregation increases germole emission by approximately 30-fold. Low-temperature NMR measurements and transmission electron microscopy (TEM) observations support the hypothesis that the origin of the AIE effect lies in restricted intramolecular rotations (IMR) of the substituent groups about the bonds connecting them to the core metallole ring.
Mullin, J.L., Tracy, H.J., Ford, J.R.. Keenan, S.R., & Fridman, F. (2007). Characteristics of aggregation induced emission in 1,1-dimethyl-2,3,4,5-tetraphenyl and 1,1,2,3,4,5-hexaphenyl siloles and germoles. Journal of Inorganic and Organometallic Polymers and Materials. 17(1), 201–213. doi.org/10.1007/s10904-006-9073-4