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Search for "actinometry" in Full Text gives 8 result(s) in Beilstein Journal of Organic Chemistry.

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

  • Pengcheng Li,
  • Daniel Kowalczyk,
  • Johannes Liessem,
  • Mohamed M. Elnagar,
  • Dariusz Mitoraj,
  • Radim Beranek and
  • Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

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  • actinometry. The system displayed exceptional stability, with operation sustained over 70 hours. A design of experiment (DOE) analysis was used to systematically investigate the influence of key parameters – photon flux, photocatalyst loading, stirring speed, and inert gas flow rate – on the hydrogen
  • . Photonic characterization The loop photoreactor using 6 LEDs was photonically characterized by chemical actinometry. Figure 6 shows the actinometer conversions and calculated photon fluxes at different irradiation times. The reasonable linear fits of the conversion (see Figure 6a) prove the applicability
  • LEDs electrical current (see Figure 7). The good linear regression shows that the chemical actinometry gave quite reliable photon flux values in the loop photoreactor. This relation was used to extrapolate the photon fluxes for experiments with more than 6 LEDs or with higher electrical current. Light
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Published 16 Jan 2024

Selectivity control towards CO versus H2 for photo-driven CO2 reduction with a novel Co(II) catalyst

  • Lisa-Lou Gracia,
  • Philip Henkel,
  • Olaf Fuhr and
  • Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

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  • from Shimadzu (GC-2030) equipped with two barrier discharge ionization detectors (BID). Every test was repeated at least twice. The photon flux was evaluated with actinometry, according to a previously published procedure [42], and it was 0.025 µE s−1. Therefore, an apparent photoluminescent quantum
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Published 17 Nov 2023

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

  • Minzan Zuo,
  • Krishnasamy Velmurugan,
  • Kaiya Wang,
  • Xueqi Tian and
  • Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

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  • authenticated by isothermal calorimetric titration or fluorescence titration and stopped-flow analysis. Furthermore, the quantum yield and reaction velocity of the photocatalysis can be verified by actinometry and UV–vis measurements. Therefore, with the aid of various analytical and spectroscopic studies, we
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Published 18 Jan 2021

Distinctive reactivity of N-benzylidene-[1,1'-biphenyl]-2-amines under photoredox conditions

  • Shrikant D. Tambe,
  • Kwan Hong Min,
  • Naeem Iqbal and
  • Eun Jin Cho

Beilstein J. Org. Chem. 2020, 16, 1335–1342, doi:10.3762/bjoc.16.114

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  • the formation of mixtures of several types of amine compounds. A photochemical quantum yield, determined by using the standard ferrioxalate actinometry, was 83% for the radical cross-coupling between 1a and Cy2NMe (see Supporting Information File 1 for details). Next, the homocoupling reactions of
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Published 18 Jun 2020

Photoreversible stretching of a BAPTA chelator marshalling Ca2+-binding in aqueous media

  • Aurélien Ducrot,
  • Arnaud Tron,
  • Robin Bofinger,
  • Ingrid Sanz Beguer,
  • Jean-Luc Pozzo and
  • Nathan D. McClenaghan

Beilstein J. Org. Chem. 2019, 15, 2801–2811, doi:10.3762/bjoc.15.273

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  • and 0.230 μM for 1Z were determined. The value for 1E is similar to the Kd value reported for BAPTA (Kd = 0.110 μM) and importantly calcium binding by the cis-form was circa 2.5-fold less than that of the trans-form [39]. This is conducive to photopromoted ion release. Chemical actinometry afforded
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Published 21 Nov 2019

A photochemical determination of luminescence efficiency of upconverting nanoparticles

  • Baptiste Amouroux,
  • Clément Roux,
  • Jean-Claude Micheau,
  • Fabienne Gauffre and
  • Christophe Coudret

Beilstein J. Org. Chem. 2019, 15, 2671–2677, doi:10.3762/bjoc.15.260

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  • efficiency of these green-emitting “nanolamps”. The agreement of the collected data with the previous published results validates this approach. Keywords: actinometry; diarylethene; lanthanide; photochemistry; upconverting nanoparticle; Introduction The photophysical property of converting low-energy light
  • measurement problem. The chemical measurement of light intensity is called actinometry and relies on the exposure of a fully standardized photosensitive compound to the light to be measured [22]. The rate of the photochemical transformation is then used to retrieve the light intensity of the beam exciting the
  • solution. Compared to physical radiometry, actinometry is directly transposable to the monitoring of photochemical transformations as it originates from the very same concept and can be performed in the same experimental conditions. It is also adapted to turbid mixtures and can be extended to polychromatic
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Published 11 Nov 2019

On the mechanism of photocatalytic reactions with eosin Y

  • Michal Majek,
  • Fabiana Filace and
  • Axel Jacobi von Wangelin

Beilstein J. Org. Chem. 2014, 10, 981–989, doi:10.3762/bjoc.10.97

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  • answers to the distinction between photocatalytic and radical chain mechanisms can be derived directly from Φ. A quantification of the photon flux is rather problematic. Recently, devices became available which use solar cells for the direct measurement of photon fluxes [33]. However, chemical actinometry
  • ][18][19][20][21]. For more details on the actinometry experiments and quantum yield determinations, see Supporting Information File 1. The observed quantum yields Φ of the studied reactions varied by almost two orders of magnitude, between 4.7 and 0.075. This already indicates the operation of
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Published 30 Apr 2014

A divergent asymmetric approach to aza-spiropyran derivative and (1S,8aR)-1-hydroxyindolizidine

  • Jian-Feng Zheng,
  • Wen Chen,
  • Su-Yu Huang,
  • Jian-Liang Ye and
  • Pei-Qiang Huang

Beilstein J. Org. Chem. 2007, 3, No. 41, doi:10.1186/1860-5397-3-41

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  • Spiroketals and the corresponding aza-spiroketals are the structural features found in a number of bioactive natural products, and in compounds possessing photochromic properties for use in the area of photochemical erasable memory, self-development photography, actinometry, displays, filters, lenses of
  • with the corresponding non-spiro analogue D, is a well known class of compounds possessing photochromic properties for use in the area of photochemical erasable memory,[10] and also found applications as self-development photography, actinometry, displays, filters, lenses of variable optical density
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Published 08 Nov 2007
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