This paper mainly focuses on the synergistic effect of Sn and N dopants to enhance the photocatalytic performance of anatase TiO2 under visible light or simulated solar light irradiation. The Sn and N co-doped TiO2 (SNT-x) photocatalysts were successfully prepared by the facile sol-gel method and the post-nitridation route in the temperature range of 400-550 °C. All the as-prepared samples were characterized in detail by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, X-ray photoelectron and electron spin resonance spectroscopy and photoelectrochemical measurements. The characterization results reveal that the co-incorporation of Sn and N atoms remarkably modifies the electronic structure of TiO2, which gives rise to a prominent separation of photogenerated charge carriers and more efficient interfacial charge-transfer reactions in a photocatalytic process. The enhanced photocatalytic activity is attributed to the intensified active oxygen species including hydroxyl radicals (˙OH) and superoxide anion radicals (O2˙(-)) for degradation of organic pollutants. And the result of photocatalytic hydrogen production further confirms the existence of the synergistic effect in the SNT-x samples, because they exhibit higher photocatalytic activity than the sum of N/TiO2 and Sn/TiO2. This work provides a paradigm to consolidate the understanding of the synergistic effect of metal and non-metal co-doped TiO2 in domains of photocatalysis and photoelectrochemistry.

Metalla-aromatics are important complexes that show unique properties owing to their highly conjugated systems,which show Hückel or Mçbius aromaticity.Recently, several metalla-aromatics showing spiro-aromaticity or saromaticity have been reported. Herein, we report the isolation of the first cyclopropametallanaphthalenes,i nw hich the metallacyclopropene ring shows s-aromaticity and weak hyperconjugative aromaticity.T he reaction of OsCl 2 (PPh 3 ) 3 with o-ethynylphenyl alkynes in the presence of PPh 3 followed by protonation with HCl yielded the first cyclopropametallanaphthalenes.T he reaction mechanism and the aromaticity were also investigated by density functional theory studies.

Metalla‐aromatics are important complexes that show unique properties owing to their highly conjugated systems, which show Hückel or Möbius aromaticity. Recently, several metalla‐aromatics showing spiro‐aromaticity or σ‐aromaticity have been reported. Herein, we report the isolation of the first cyclopropametallanaphthalenes, in which the metallacyclopropene ring shows σ‐aromaticity and weak hyperconjugative aromaticity. The reaction of OsCl2(PPh3)3 with o‐ethynylphenyl alkynes in the presence of PPh3 followed by protonation with HCl yielded the first cyclopropametallanaphthalenes. The reaction mechanism and the aromaticity were also investigated by density functional theory studies.

Treatment of the SiMe3‐protected dichloro‐rhenium carbyne complexes Re{≡CCH=C(R)C≡CSiMe3}Cl2(PMe2Ph)3 (R = CMe3, 1‐adamantyl) with CsF in methanol directly afforded the 12‐membered metallacycles {ReCl(PMe2Ph)3}2{≡CCH=C(R)C≡C−}2. The electronic structure of the metallacycle was investigated by density functional calculations. The UV‐vis spectrum of the metallacycle shows a red‐shifted band compared to that of the starting dichlorocarbyne complex. Treatment of {ReCl(PMe2Ph)3}2{≡CCH=C(CMe3)C≡C−}2 with HCl produced the dichloro‐rhenium carbyne complex Re{≡CCH=C(CMe3)C≡CH}Cl2(PMe2Ph)3, which is consistent with the electronic structure of the 12‐membered metallacycles.