title: Helical Self-Assembly-Induced Singlet-Triplet Emissive Switching in a Mechanically Sensitive System.
abstract: In nanoscience, chirality has shown a significant ability to tune materials' electronic properties, whereas imposing macrochirality into the regulation of singlet-triplet features of organic optoelectronics remains a challenging research topic. Since the tuning for singlet and triplet excited-state properties in a single π-functional molecule connects to its multicolor luminescent application and potential improvement of internal quantum efficiency, we here report that supramolecular chirality can be employed to toggle the singlet and triplet emissions in a well-designed asterisk-shaped molecule. Employing a hexathiobenzene-based single luminophore as a prototype and functionalizing it with chiral α-lipoiate side groups, we find that helical nanoarchitectures can accordingly form in mixed DMF/H2O solution. On this basis, switching between fluorescence and phosphorescence of the material can be realized upon helical self-assembly and dissociation. Such a behavior can be attributed to a helical-conformation-dependent manipulation of the intersystem crossing. Furthermore, reversible mechanoluminescence of the corresponding solid sample was also observed to rely on an analogous molecular self-assembly alternation. These results can probably provide new visions for the development of next-generation supramolecular chiral functional materials.
authors.affiliation: Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, School of Chemistry and Chemical Engineering, Shanghai Jiaotong University , Shanghai 200240, China.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, China.
authors.forename: Yunyun
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Yin
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Hang
authors.affiliation: Division of Theoretical Chemistry and Biology School of Biotechnology, KTH Royal Institute of Technology , SE-10691 Stockholm, Sweden.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Division of Theoretical Chemistry and Biology School of Biotechnology, KTH Royal Institute of Technology , SE-10691 Stockholm, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Ågren
authors.affiliation: Department of Chemistry and Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , Shanghai 200433, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yi
authors.affiliation: Shanghai Key Laboratory of Electrical Insulation and Thermal Aging, School of Chemistry and Chemical Engineering, Shanghai Jiaotong University , Shanghai 200240, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University , Shanghai 200433, China.
authors.forename: Liangliang
authors.identifier: 0000-0001-6268-3351
authors.initials: L
authors.lastname: Zhu