Dataset Information

Solution and Solid-State Emission Toggling of a Photochromic Hydrazone.

ABSTRACT: The proliferation of light-activated switches in recent years has enabled their use in a broad range of applications encompassing an array of research fields and disciplines. All current systems, however, have limitations (e.g., from complicated synthesis to incompatibility in biologically relevant media and lack of switching in the solid-state) that can stifle their real-life application. Here we report on a system that packs most, if not all, the desired, targeted and sought-after traits from photochromic compounds (bistability, switching in various media ranging from serum to solid-state, while exhibiting ON/OFF fluorescence emission switching, and two-photon assisted near-infrared light toggling) in an easily accessible structure.

SUBMITTER: Shao B

PROVIDER: S-EPMC6693799 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

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Solution and Solid-State Emission Toggling of a Photochromic Hydrazone.

Shao Baihao B Baroncini Massimo M Qian Hai H Bussotti Laura L Di Donato Mariangela M Credi Alberto A Aprahamian Ivan I

Journal of the American Chemical Society 20180925 39

The proliferation of light-activated switches in recent years has enabled their use in a broad range of applications encompassing an array of research fields and disciplines. All current systems, however, have limitations (e.g., from complicated synthesis to incompatibility in biologically relevant media and lack of switching in the solid-state) that can stifle their real-life application. Here we report on a system that packs most, if not all, the desired, targeted and sought-after traits from ...[more]

PMID: 30251843

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Project description:In this work, a series of γ-substituted diphenylnaphthalonitriles were synthesized and characterized. They show efficient emission in solution and in the aggregated state and their environment responsiveness is based on having variable substituents at the para-position of the two phenyl moieties. The excited state properties were fully investigated in tetrahydrofuran (THF) solutions and in THF/H2O mixtures. The size of the aggregates in aqueous media were measured by dynamic light scattering (DLS). The steady-state and time-resolved photoluminescence spectroscopy studies revealed that all the molecules show intense fluorescence both in solution and in the aggregated state. In THF solutions, a blue emission was observed for the unsubstituted (H), methyl- (Me) and tert-butyl- (t-Bu) substituted γ-diphenylnaphthalonitriles, which can be attributed to a weak π-donor capability of these groups. On the other hand, the methoxy- (OMe), methylsulfanyl- (SMe) and dimethylamino- (NMe2) substituted compounds exhibit a progressive red-shift in emission compared to H, Me and t-Bu due to a growing π-electron donating capability. Interestingly, upon aggregation in water-containing media, H, Me and t-Bu show a slight red-shift of the emission and a blue-shift is observed for OMe, SMe and NMe2. The crystal structure of Me allowed a detailed discussion of the structure-property relationship. Clearly, N-containing substituents such as NMe2 possess more electron-donating ability than the S-based moieties such as SMe. Moreover, it was found that NMe2 showed higher luminescence quantum yields (ΦF) in comparison to SMe, indicating that N-substituted groups could enhance the fluorescence intensity. Therefore, the π-donor nature of the substituents on the phenyl ring constitutes the main parameter that influences the photophysical properties, such as excited state lifetimes and photoluminescence quantum yields. Hence, a series of highly luminescent materials from deep blue to red emission depending on substitution and environment is reported with potential applications in sensing, bioimaging and optoelectronics.

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Solution and Solid-State Emission Toggling of a Photochromic Hydrazone.

Publications

Solution and Solid-State Emission Toggling of a Photochromic Hydrazone.

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