title: Tuning for Visible Fluorescence and Near-Infrared Phosphorescence on a Unimolecular Mechanically Sensitive Platform via Adjustable CH-π Interaction.
abstract: CH-π interaction-assisted alignment of organic conjugated systems has played an important role to regulate molecular electronic and photophysical properties, whereas harnessing such a smart noncovalent interaction into the tuning of unimolecular complex emissive bands covering a wide spectral region remains a challenging research topic. Since the tuning for visible and near-infrared emissive properties in a single π-functional platform relates to its multicolor luminescent behaviors and potential superior application in analysis, bioimaging, and sensing, herein, we report a proportional control of the singlet and triplet emissions that cover visible and near-infrared spectral regions, respectively, can be straightforwardly achieved by CH-π interaction-assisted self-assembly at the unimolecular level. Employing an octathionaphthalene-based single luminophore as a prototype, we find that a strength-adjustable CH-π interaction-assisted self-assembly can be established in mixed DMF/H2O and in the film state. The hybridization of planar local excited and intramolecular charge transfer transitions occurs on the basis, allowing a competitive inhibition to the intersystem crossing process to generate a complex emission composed of visible fluorescence and near-infrared phosphorescence. Furthermore, reversible mechanochromic and mechanoluminescent conversions of the corresponding solid sample can both be observed to rely on a corresponding self-assembly alternation. These results can probably provide new visions for the development of future intelligent and multifunctional luminescent materials.
authors.affiliation: Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing, School of Chemistry and Chemical Engineering, Shanghai Jiaotong University , 800 Dongchuan Road, 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: Pei
authors.initials: P
authors.lastname: Zhao
authors.affiliation: Division of Theoretical Chemistry and Biology School of Biotechnology, KTH Royal Institute of Technology , Stockholm SE-10691, Sweden.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power, Shanghai University of Electric Power , Shanghai 200090, China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Chen
authors.affiliation: Division of Theoretical Chemistry and Biology School of Biotechnology, KTH Royal Institute of Technology , Stockholm SE-10691, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Ågren
authors.affiliation: Shanghai Key Laboratory of Electrical Insulation and Thermal Ageing, School of Chemistry and Chemical Engineering, Shanghai Jiaotong University , 800 Dongchuan Road, 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: http://orcid.org/0000-0001-6268-3351
authors.initials: L
authors.lastname: Zhu
keywords: CH−π interaction; mechanical stimuli; tunable intersystem crossing; unimolecular complex emission; visible fluorescence and near-infrared phosphorescence