Overall water splitting on (Ga(1-x)Zn(x))(N(1-x)O(x)) solid solution photocatalyst: relationship between physical properties and photocatalytic activity

The physical and photocatalytic properties of a novel solid solution between GaN and ZnO, (Ga(1-x)Zn(x))(N(1-x)O(x)), are investigated. Nitridation of a mixture of Ga(2)O(3) and ZnO at 1123 K for 5-30 h under NH(3) flow results in the formation of a (Ga(1-x)Zn(x))(N(1-x)O(x)) solid solution with x = 0.05-0.22. With increasing nitridation time, the zinc and oxygen concentrations decrease due to reduction of ZnO and volatilization of zinc, and the crystallinity and band gap energy of the product increase. The highest activity for overall water splitting is obtained for (Ga(1-x)Zn(x))(N(1-x)O(x)) with x = 0.12 after nitridation for 15 h. The crystallinity of the catalyst is also found to increase with increasing the ratio of ZnO to Ga(2)O(3) in the starting material, resulting in an increase in activity.     

Rapid and sensitive HPLC method for the simultaneous determination of paraquat and diquat in human serum.

A rapid and sensitive HPLC method for the simultaneous determination of paraquat and diquat in human serum has been developed. After deproteinization of the serum with 10% trichloroacetic acid, the samples were separated on a reversed-phase column, and subsequently reduced to their radicals with alkaline sodium hydrosulfite solution. These radicals were monitored with a UV detector at 391 nm. This method permitted the reliable quantification of paraquat over linear ranges of 50 ng - 10 microg/ml and 100 ng - 10 microg/ml for diquat in human serum. The within- and between-day variations are lower than 2.3 and 2.2%, respectively. This technique was also utilized to determine the paraquat and diquat serum levels in a patient who had ingested herbicide (Prigrox L) containing paraquat and diquat.     

Photochemische Reaktionen. 109. Mitteilung [1]. Zur Photochemie konjugierter δ-Keto-enone und β,γ,δ,ϵ-ungesättigter Ketone

Photochemistry of Conjugated δ-Keto-enones and β,γ,δ,?-Unsaturated Ketones On ¹π,π*-excitation the δ-keto-enones 5–8 are isomerized to compounds B ( 18 , 22 , 26 , 28 ) via 1,3-acyl shift and to compounds C ( 19 , 23 , 27 , 29 ) via 1,2-acyl shift, whereas the β,γ,δ,?-unsaturated ketone 9 gives the isomers 32 and 33 by 1,2-and 1,5-acyl shift, respectively. Furthermore, isomerization of 6 to 24 , dimerization of 8 to 30 and addition of methanol to 8 ( 8 → 31 ) is observed. Unlike 7 and 8 the acyclic ketones 5 , 6 and 9 undergo photodecarbonylation on ¹π,π*-excitation ( 5 → 20 , 21 ; 6 → 20 , 25 ; (E)- 9 → 35–38 ). Evidence is given, that the conversion to B as well as the photodecarbonylation of 5,6 and 9 arise from an excited singulet state, but the conversion to C as well as the dimerization of 8 from the T₁-state.     

Deep‐UV tip‐enhanced Raman scattering

We report for the first time the tip‐enhancement of resonance Raman scattering using deep ultraviolet (DUV) excitation wavelength. The tip‐enhancement was successfully demonstrated with an aluminum‐coated silicon tip that acts as a plasmonic material in DUV wavelengths. Both the crystal violet and adenine molecules, which were used as test samples, show electronic resonance at the 266‐nm excitation used in the experiments. With results demonstrated here, molecular analysis and imaging with nanoscale spatial resolution in DUV resonance Raman spectroscopy can be realized using the tip‐enhancement effect. Copyright © 2009 John Wiley & Sons, Ltd.     

The synthetic protocol for α-bromocarbonyl compounds via brominations

α-Bromocarbonyl compound easily generates α-radicals in the presence of a proper initiator, such as copper salt. Recently, tertiary-alkylation reaction using α-bromocarbonyl compound as a tertiary alkyl source is recognized as one of the most important alkylation reactions. The reactions using α-bromocarbonyl compound are increasing, whereas synthetic methods for various functionalized α-bromocarbonyl compounds are not summarized. Generally, α-bromocarbonyl compounds can be synthesized from the corresponding carboxylic acids via α-bromo acid bromide, but the brominations of carboxylic acids are sometimes problematic. In this paper, we will report some technical information for a bromination and synthetic examples of representative α-bromocarbonyl compounds.     

Bottom‐Up On‐Surface Synthesis of Two‐Dimensional Graphene Nanoribbon Networks and Their Thermoelectric Properties

Graphene, the one‐atom‐thick two‐dimensional (2D) carbon material, has attracted tremendous interest in both academia and industry due to its outstanding electrical, mechanical, and thermal properties. For electronic applications, the challenging task is to make it as a semiconductor. The bottom‐up synthesis of semiconducting one‐dimensional (1D) nanometer‐wide graphene strips, namely, graphene nanoribbons (GNRs), has attracted much attention owing to its promising electronic, optical, and magnetic properties. In this regard, we report the fabrication of cove‐type 2D GNR networks (GNNs) via the interconnection of 1D self‐assembled GNRs on the surface of Au(111). The cove‐type 2D GNRs networks (GNNs) were fabricated from the GNR, 5‐CGNR‐1‐1 , synthesized using the precursor of DBSP . Annealing of high‐density self‐assembled GNRs on the surface of Au(111) through two‐zone chemical vapour deposition (2Z CVD) successfully generated a 2D interconnected structure with high yield via the fusion and ladder coupling reactions of GNR chains. In order to validate the later fusion reaction, we have also synthesized the GNR, 7‐AGNR‐1‐1 , using the precursor of DBBA . The GNNs, which consist of hybridized metallic‐like and semiconducting GNRs, are a new class of carbon‐based materials. Further, we applied this material for thermoelectric (TE) applications and found a very low cross‐plane thermal conductivity of 0.11 Wm^?1 K^?1, which is one of the lowest value among the carbon‐based materials as well as inorganic semiconductors, while maintaining the cross‐plane electrical conductivity of 188 S m^?1.     

Heterogeneous assembly of silver(I) and calcium(II) ions accompanying a dimer formation of cyclo(L-Ala-L-Met)3

Heterogeneous assembly of three Ag+ and one Ca2+ ion has been accomplished in a dimeric structure of cyclic hexapeptides, cyclo(l-Ala-l-Met)3.