A New Photocage Derived from Fluorene

Reinfelds, Matiss; Cosel, Jan von; Falahati, K.; Hamerla, Carsten; Slanina, Tomáš; Burghardt, Irène; Heckel, Alexander

doi:10.1002/chem.201802390

Cited by 16 publications

(38 citation statements)

References 61 publications

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“…The photo reaction of c4m‐ac was followed by HPLC and of p HP‐t and p HP‐ac by UV‐vis spectroscopy. All quantum yields ( Φ ) were measured in triplicates and calculated as previously described …”

Section: Methodsmentioning

confidence: 99%

“…The plot was fitted using following exponential decay function [Eq. (3)], where A 1 and t 1 are fit parameters and y 0 is a constant

true y = A_{1} e^{\frac{t_{i r r}}{t_{1}}} + y_{0}

…”

Section: Methodsmentioning

confidence: 99%

“…The initial rate of the concentration change ( y′ ) at the beginning of the irradiation can be calculated by deriving Equation (3) and inserting the corresponding fit parameters for t irr =0 [Eq. (4)]:

true y' = - \frac{A_{1} e^{\frac{- t_{i r r}}{t_{1}}}}{t_{1}}

…”

Section: Methodsmentioning

confidence: 99%

“…For c4m‐ac, Φ is then calculated by Equation (5), where c is the concentration of the irradiated solution, V is the volume of the irradiated sample, y′ is the change in concentration, n p is the photon flux of the light source determined by actinometry and A λ is the absorbance of the PAG solution at the irradiation wavelength

true Φ = \frac{c \cdot V \cdot y^{'}}{n_{p} \cdot (1 - 10^{- A_{λ}})}

…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Coumarin‐4‐ylmethyl‐ and p‐Hydroxyphenacyl‐Based Photoacid Generators with High Solubility in Aqueous Media: Synthesis, Stability and Photolysis

et al. 2020

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(Coumarin‐4‐yl)methyl (c4m) and p‐hydroxyphenacyl (pHP)‐based compounds are well known for their highly efficient photoreactions, but often show limited solubility in aqueous media. To circumvent this, we synthesized and characterized the two new c4m and pHP‐based photoacid generators (PAGs), 7‐[bis(carboxymethyl)amino]‐4‐(acetoxymethyl)coumarin (c4m‐ac) and p‐hydroxyphenacyl‐2,5,8,11‐tetraoxatridecan‐13‐oate (pHP‐t), and determined their solubilities, stabilities and photolysis in aqueous media. The two compounds showed high solubilities in water of 2.77 mmol L−1±0.07 mmol L−1 (c4m‐ac) and 124.66 mmol L−1±2.1 mmol L−1 (pHP‐t). In basic conditions at pH 9, solubility increased for c4m‐ac to 646.46 mmol L−1±0.63 mmol L−1, for pHP‐t it decreased to 34.68 mmol L−1±0.62 mmol L−1. Photochemical properties of the two PAGs, such as the absorption maxima, the maximum molar absorption coefficients and the quantum yields, were found to be strongly pH‐dependent. Both PAGs showed high stabilities s24h ≥95 % in water for 24 h, but decreasing stability with increasing pH value due to hydrolysis. The present study contributes to a clearer insight into the synthesis, solubilities, stabilities, and photolysis of c4m and pHP‐based PAGs for further photochemical applications when high PAG concentrations are required, such as in polymeric foaming.

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Section: Methodsmentioning

confidence: 99%

“…The plot was fitted using following exponential decay function [Eq. (3)], where A 1 and t 1 are fit parameters and y 0 is a constant

true y = A_{1} e^{\frac{t_{i r r}}{t_{1}}} + y_{0}

…”

Section: Methodsmentioning

confidence: 99%

true y' = - \frac{A_{1} e^{\frac{- t_{i r r}}{t_{1}}}}{t_{1}}

…”

Section: Methodsmentioning

confidence: 99%

true Φ = \frac{c \cdot V \cdot y^{'}}{n_{p} \cdot (1 - 10^{- A_{λ}})}

…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Coumarin‐4‐ylmethyl‐ and p‐Hydroxyphenacyl‐Based Photoacid Generators with High Solubility in Aqueous Media: Synthesis, Stability and Photolysis

et al. 2020

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“…Fluorenol or 9‐hydroxyfluorene is a secondary alcohol. The reactivity of both the hydroxyl group and the hydrogen atom at the 9‐position of fluorene are enhanced due to the presence of the cyclopentane moieties of fluorenol, and among other applications, these compounds have been studied as especially biomarkers and fluorescent dyes . The aromaticity of the fluorene skeleton also makes the fluorenol derivative relatively highly acidic; the acid dissociation constants of the hydroxyl group and of the hydrogen atom at the 9‐position were reported to be 10.3 and 8.9, respectively, which are much larger than those of aliphatic alcohols and comparable to those of phenols .…”

Section: Methodsmentioning

confidence: 99%

Reversible Hydrogen Releasing and Fixing with Poly(Vinylfluorenol) through a Mild Ir‐Catalyzed Dehydrogenation and Electrochemical Hydrogenation

Kato

Oka

Yoshimasa

et al. 2019

Macromol. Rapid Commun.

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The radical polymerization of 2‐vinylfluorenol, an alcohol derivative of vinylfluorene, gives poly(vinylfluorenol), which quantitatively releases hydrogen gas (≈110 mL per gram polymer at standard temperature and pressure) by simply warming at 100 °C with an iridium catalyst. A high population of fluorenol units in the polymer accomplishes a large formula‐weight‐based theoretical hydrogen density (1.0 wt%). The dehydrogenated ketone derivative, poly(vinylfluorenone), exhibits reversible negative‐charge storage with a high density of 260 mAh g−1. The electrolytically reduced poly(vinylfluorenone) is momentarily hydrogenated in the presence of an electrolyte with water as the hydrogen source to be converted to the original poly(vinylfluorenol). The formed poly(vinylfluorenol) almost quantitatively evolves hydrogen gas similar to the starting poly(vinylfluorenol). Both hydrogen and charge storage with the organic fluorenol/fluorenone polymer suggest a new type of energy‐storage configuration.

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Rethinking Uncaging: A New Antiaromatic Photocage Driven by a Gain of Resonance Energy

Hermanns

Scheurer

Kersten

et al. 2021

Chemistry A European J

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Photoactivatable compounds for example photoswitches or photolabile protecting groups (PPGs, photocages) for spatiotemporal light control, play a crucial role in different areas of research. For each application, parameters such as the absorption spectrum, solubility in the respective media and/or photochemical quantum yields for several competing processes need to be optimized. The design of new photochemical tools therefore remains an important task. In this study, we exploited the concept of excited‐state‐aromaticity, first described by N. Colin Baird in 1971, to investigate a new class of photocages, based on cyclic, ground‐state‐antiaromatic systems. Several thio‐ and nitrogen‐functionalized compounds were synthesized, photochemically characterized and further optimized, supported by quantum chemical calculations. After choosing the optimal scaffold, which shows an excellent uncaging quantum yield of 28 %, we achieved a bathochromic shift of over 100 nm, resulting in a robust, well accessible, visible light absorbing, compact new photocage with a clean photoreaction and a high quantum product (ϵ⋅Φ) of 893 M−1 cm−1 at 405 nm.

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A New Photocage Derived from Fluorene

Cited by 16 publications

References 61 publications

Coumarin‐4‐ylmethyl‐ and p‐Hydroxyphenacyl‐Based Photoacid Generators with High Solubility in Aqueous Media: Synthesis, Stability and Photolysis

Coumarin‐4‐ylmethyl‐ and p‐Hydroxyphenacyl‐Based Photoacid Generators with High Solubility in Aqueous Media: Synthesis, Stability and Photolysis

Reversible Hydrogen Releasing and Fixing with Poly(Vinylfluorenol) through a Mild Ir‐Catalyzed Dehydrogenation and Electrochemical Hydrogenation

Rethinking Uncaging: A New Antiaromatic Photocage Driven by a Gain of Resonance Energy

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