Semiconductive property of elementary substance is an interesting and attractive phenomenon. We obtain a breakthrough that fibrous phase red phosphorus, a recent discovered modification of red phosphorus by Ruck et al., can work as a semiconductor photocatalyst for visible-light-driven hydrogen (H2 ) evolution. Small sized fibrous phosphorus is obtained by 1) loading it on photoinactive SiO2 fibers or by 2) smashing it ultrasonically. They display the steady hydrogen evolution rates of 633 μmol h(-1) g(-1) and 684 μmol h(-1) g(-1) , respectively. These values are much higher than previous amorphous P (0.6 μmol h(-1) g(-1) ) and Hittorf P (1.6 μmol h(-1) g(-1) ). Moreover, they are the highest records in the family of elemental photocatalysts to date. This discovery is helpful for further understanding the semiconductive property of elementary substance. It is also favorable for the development of elemental photocatalysts.
Herein, we report two new types of twisted polycyclic arenes (2 a, b and 3 a, b) with constitutionally isomeric π-backbones, which are synthesized by controlling the Scholl reaction of 1,2,4,5-tetra(naphth-2-yl)-3,6-diphenylbenzene (1) with properly positioned electron-donating substituents. With a polycyclic backbone containing two [5]helicene and four [4]helicene moieties, 2 a and b are new members of multiple helicenes with interesting stereochemistries. The as-synthesized 2 a and b are the twisted isomers, and thermal isomerization of twisted-2 b results in anti-2 b, a more stable stereoisomer. Both twisted- and anti-2 b have been fully characterized, and the thermal isomerization of twisted-2 b has been studied with H NMR spectroscopy and DFT calculations. Compounds 3 a and b are new members of twistacenes, the benzannulated pentacene backbone of which exhibits an end-to-end twist as found from the crystal structure. Twisted- and anti-2 b are also found to function as p-type semiconductors in solution-processed thin film transistors, whereas the thin films of 3 b appear insulating presumably due to the lack of π-π interactions.
Semiconductive property of elementary substance is an interesting and attractive phenomenon. We obtain a breakthrough that fibrous phase red phosphorus, a recent discovered modification of red phosphorus by Ruck et al., can work as a semiconductor photocatalyst for visible-light-driven hydrogen (H 2 ) evolution. Small sized fibrous phosphorus is obtained by 1) loading it on photoinactive SiO 2 fibers or by 2) smashing it ultrasonically. They display the steady hydrogen evolution rates of 633 mmol h À1 g À1 and 684 mmol h À1 g À1 , respectively. These values are much higher than previous amorphous P (0.6 mmol h À1 g À1 ) and Hittorf P (1.6 mmol h À1 g À1 ). Moreover, they are the highest records in the family of elemental photocatalysts to date. This discovery is helpful for further understanding the semiconductive property of elementary substance. It is also favorable for the development of elemental photocatalysts.
The little match girl a character in Hans Christian Andersen's fairy tale, curiously stares at the bubbles popping up from the match head. In the Communication on page 9580 ff., Z. R. Shen, J. C. Yu et al. unveil the mystery of the magical scene: phosphorus (match head) in water can generate hydrogen (bubbles) under illumination. The image (designed by Z. F. Hu) depicts the process of hydrogen evolution on fibrous‐phase phosphorus, a record‐breaking photocatalyst.
A new trefoil-shaped molecular architecture consisting of three conjugated macrocycles was synthesized through an unprecedented 3-fold copper catalyzed [4 + 2] benzannulation. DFT calculations indicate that the most stable conformation of this trefoil macrocycle is D 3 -symmetric. In agreement with the calculated results, the trefoil macrocycle in single crystals exists as a pair of enantiomers with D 3 -symmetry and exhibits interesting honeycomb-like supramolecular structures.
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