Graphitisches Kohlenstoffnitrid (g‐CN) ist ein übergangsmetallfreier Halbleiter, der eine Vielzahl von photokatalytischen Reaktionen unterstützt. Obwohl oft ein photoinduzierter Elektronentransfer ...als Mechanismus postuliert wird, ist der protonengekoppelte Elektronentransfer (PCET) der bevorzugte Weg für Substrate mit X−H‐Bindungen. Bei der Anregung einer (sp2)N‐reichen Struktur von g‐CN mit sichtbarem Licht verhält sie sich wie eine Photobase – es kommt zu einem reduktivem Quenching, begleitet von der Abstraktion eines Protons aus einem Substrat. Die Ergebnisse der Modellierung ermöglichten es uns, aktive Stellen für PCET zu identifizieren – die “dreieckigen Taschen” an den Kantenfacetten von g‐CN. Excited‐State‐PCET vom Substrat zu g‐CN wurde eingesetzt um die endo‐(sp3)C−H‐Bindung in Oxazolidin‐2‐onen selektiv zu spalten, gefolgt vom Einfangen des Radikals mit O2. Diese Reaktion ergibt 1,3‐Oxazolidin‐2,4‐Dionen. Die Messung des scheinbaren pKa‐Wertes und die Modellierung deuten darauf hin, dass der angeregte g‐CN‐Zustand X−H‐Bindungen spalten kann, die durch eine freie Bindungsdissoziationsenergie (BDFE) von ≈100 kcal mol−1 gekennzeichnet sind.
Die Umwandlung von Oxazolidinonen in entsprechende Oxazolidin‐2,4‐Dione wird durch mpg‐CN, einem Kohlenstoffnitrid‐Photokatalysator, unter Verwendung von Sauerstoffgas als Oxidationsmittel ermöglicht. Die Reaktion läuft über protonengekoppelten Elektronentransfer ab. Der Mechanismus dieser Umwandlung wird durch photokatalytische Experimente, transiente Absorptionsspektroskopie und DFT‐Berechnungen ermittelt.
Multiplex optical detection in live cells is challenging due to overlapping signals and poor signal‐to‐noise associated with some chemical reporters. To address this, the application of spectral ...phasor analysis to stimulated Raman scattering (SRS) microscopy for unmixing three bioorthogonal Raman probes within cells is reported. Triplex detection of a metallacarborane using the B−H stretch at 2480–2650 cm−1, together with a bis‐alkyne and deuterated fatty acid can be achieved within the cell‐silent region of the Raman spectrum. When coupled to imaging in the high‐wavenumber region of the cellular Raman spectrum, nine discrete regions of interest can be spectrally unmixed from the hyperspectral SRS dataset, demonstrating a new capability in the toolkit of multiplexed Raman imaging of live cells.
Hyperspectral stimulated Raman scattering (SRS) microscopy with spectral phasor analysis enables the multiplex detection of bioorthogonal Raman groups in cells. Unmixing of the overlapping alkyne and deuterium signals together with the detection of metallacarboranes is reported within the cell‐silent region of the Raman spectrum.
Double-cluster mono and dianions containing cobaltadicarbollide and 12-vertex carborane structures interconnected via 1,4-dioxahexane chain were prepared.
The treatment of 1,2-, 1,7- and ...1,12-carbaborane lithiated isomers with 3,3′-Co-8-(CH
2CH
2O)
2-(1,2-C
2B
9H
10)-(1′,2′-C
2B
9H
11) (
1) at molar ratios 1:1 or 1:2 at room temperature in THF leads generally to the formation of a series of orange double-cluster mono and dianions. These were characterized by NMR and MS methods as 1′′-X-1′′,2′′-
closo-C
2B
10H
11
−,
2
−; 1′′-X-1′′,7′′-
closo-C
2B
10H
11
−,
3
− and 1′′-X-1′′,12′′-
closo-C
2B
10H
11,
4
− for the monoanions, whereas 1′′,2′′-X
2-1′′,2′′-
closo-C
2B
10H
10
2−,
2
2−; 1′′,7′′-X
2-1′′,7′′-
closo-C
2B
10H
10
2−,
3
2−; and 1′′,12′′-X
2-1′′,12′′-
closo-C
2B
10H
10
2−,
4
2− for the dianions (where X
=
3,3′-Co-8-(CH
2CH
2O)
2-(1,2-C
2B
9H
10)-1′,2′-(C
2B
9H
11)). Moreover, these borane-cage subunits can be easily modified
via attaching variable substituents onto cage carbon and boron vertices, which makes these compounds structurally flexible potential candidates for BNCT of cancer and HIV-PR inhibition.
Decarbonisation of the economy has become a priority at the global level, and the resulting legislative pressure is pushing the chemical and energy industries away from fossil fuels. Microbial ...electrosynthesis (MES) has emerged as a promising technology to promote this transition, which will further benefit from the decreasing cost of renewable energy. However, several technological challenges need to be addressed before the MES technology can reach its maturity. The aim of this review is to critically discuss the bottlenecks hampering the industrial adoption of MES, considering the whole production process (from the CO
source to the marketable products), and indicate future directions. A flexible stack design, with flat or tubular MES modules and direct CO
supply, is required for site-specific decentralised applications. The experience gained for scaling-up electrochemical cells (e.g. electrolysers) can serve as a guideline for realising pilot MES stacks to be technologically and economically evaluated in industrially relevant conditions. Maximising CO
abatement rate by targeting high-rate production of acetate can promote adoption of MES technology in the short term. However, the development of a replicable and robust strategy for production and in-line extraction of higher-value products (e.g. caproic acid and hexanol) at the cathode, and meaningful exploitation of the currently overlooked anodic reactions, can further boost MES cost-effectiveness. Furthermore, the use of energy storage and smart electronics can alleviate the fluctuations of renewable energy supply. Despite the unresolved challenges, the flexible MES technology can be applied to decarbonise flue gas from different sources, to upgrade industrial and wastewater treatment plants, and to produce a wide array of green and sustainable chemicals. The combination of these benefits can support the industrial adoption of MES over competing technologies.
Abstract
A Pd‐induced cascade B–C
vinyl
coupling that produces multiple B–C
vinyl
bonds starting from a single B–I bond has been demonstrated. The process is most probably stimulated by the ...geometrical disposition of the B–H bonds confronting the B–Pd sites, along with the hydride character of the B–H units. Two and one B–C
vinyl
couplings on the metallacarborane substrate have been generally obtained, but formation up to six B–C
vinyl
bonds has been observed. A theoretical reaction mechanism involving an unprecedented B–H activation is proposed to interpret the multisubstitution process.
Iod verbindet: Bei der Umsetzung eines schwach koordinierenden Carboranylphosphanliganden mit I2 entsteht ein Addukt, das im festen Zustand eine verbrückende P⋅⋅⋅II⋅⋅⋅P‐Einheit enthält (siehe Bild; ...I violett, P orange, C grau, B rosa, H weiß). Aus DFT‐Rechnungen und einer Vielzahl experimenteller Tests lässt sich folgern, dass dieses Strukturmotiv auch in Lösung vorliegt.
Die Theta‐förmige amphiphile Struktur sowie die Ladungsdichte und die Formtreue des Cobaltabisdicarbollid‐Anions (3,3′‐Co(1,2‐C2B9H11)2−, COSAN−) führen zu einem ungewöhnlichen Aggregationsverhalten. ...In ihrer Zuschrift auf S. 5410 ff. beschreiben P. Bauduin et al. die konzentrationsabhängige Bildung von sowohl Vesikeln als auch Micellen in Wasser.
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