Highly Efficient Aggregation-Induced Room-Temperature Phosphorescence with Extremely Large Stokes Shift Emitted from Trinuclear Gold(I) Complex Crystals.

Osamu Tsutsumi,Kyohei Hisano,Hitoya Nakasato,Kenta Yamaguchi,Yuki Kuroda,Kaori Fujisawa,Masakazu Tamaru,Supattra Panthai,Shingo Shimai

doi:10.3390/molecules24244606

Osamu Tsutsumi, Kyohei Hisano + Show 7 more

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https://doi.org/10.3390/molecules24244606

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Journal: Molecules (Basel, Switzerland)	Publication Date: Dec 16, 2019
Citations: 10	License type: CC BY 4.0

Affiliation: Ritsumeikan University

Abstract

Highly efficient (≈75% quantum yield), aggregation-induced phosphorescence is reported. The phosphorescence is emitted at room temperature and in the presence of air from crystals of trinuclear Au(I) complexes, accompanied by an extremely large Stokes shift of 2.2 × 104 cm−1 (450 nm). The mechanism of the aggregation-induced room-temperature phosphorescence from the Au complex crystals was investigated in terms of the crystal packing structure and the primary structure of the molecules. It was found that two kinds of intermolecular interactions occurred in the crystals, and that these multiple dual-mode intermolecular interactions in the crystals play a crucial role in the in-air room-temperature phosphorescence of the trinuclear Au(I) complexes.

Highlights

Aggregation-induced emission (AIE) is a fascinating phenomenon wherein molecules display intense luminescence by aggregation [1,2,3]
The molecular structure and synthesis of DTnare shown in Scheme 1
Our molecular design strategy centered around the use of a simple ligand without bulky substituents around the Au atoms to improve the Au–Au intermolecular interaction, which is typically blocked by the steric hindrance of bulky ligands

Summary

Introduction

Aggregation-induced emission (AIE) is a fascinating phenomenon wherein molecules display intense luminescence by aggregation [1,2,3]. Organic molecules can exhibit efficient luminescence in dilute solutions, but their luminescence efficiency is decreased by aggregation in condensed phases by aggregation-caused quenching (ACQ), a well-known phenomenon which is very common among organic luminescent molecules [3,4,5,6]. The development of practical applications using luminescent molecules is hindered by the ACQ of conventional luminogens; and attaining intensive photoluminescence in condensed phases or aggregates is a vital parameter for improving their usefulness. Great effort has been devoted to further restricting intramolecular motions using the intermolecular interactions of AIEgens

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