Tuning for Visible Fluorescence and Near-Infrared Phosphorescence on a Unimolecular Mechanically Sensitive Platform via Adjustable CH−π Interaction

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• 作者：Hongwei Wu ; Pei Zhao ; Xin Li ; Wenbo Chen ; Hans Ågren ; Qing Zhang ; Liangliang Zhu
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2017
• 出版时间：February 1, 2017
• 年：2017
• 卷：9
• 期：4
• 页码：3865-3872
• 全文大小：587K
• ISSN：1944-8252

文摘

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.