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1.
Hongyu Zhang Changlong Hao Aihua Qu Maozhong Sun Liguang Xu Chuanlai Xu Hua Kuang 《Angewandte Chemie (International ed. in English)》2020,59(18):7131-7138
The accumulation and deposition of β‐amyloid (Aβ) plaques in the brain is considered a potential pathogenic mechanism underlying Alzheimer's disease (AD). Chiral l/d ‐FexCuySe nanoparticles (NPs) were fabricated that interfer with the self‐assembly of Aβ42 monomers and trigger the Aβ42 fibrils in dense structures to become looser monomers under 808 nm near‐infrared (NIR) illumination. d ‐FexCuySe NPs have a much higher affinity for Aβ42 fibrils than l ‐FexCuySe NPs and chiral Cu2?xSe NPs. The chiral FexCuySe NPs also generate more reactive oxygen species (ROS) than chiral Cu2?xSe NPs under NIR‐light irradiation. In living MN9D cells, d ‐NPs attenuate the adhesion of Aβ42 to membranes and neuron loss after NIR treatment within 10 min without the photothermal effect. In‐vivo experiments showed that d ‐FexCuySe NPs provide an efficient protection against neuronal damage induced by the deposition of Aβ42 and alleviate symptoms in a mouse model of AD, leading to the recovery of cognitive competence. 相似文献
2.
Prof. Jun Xu Dr. Xia Yang Dr. Qing‐Dan Yang Dr. Xing Huang Dr. Yongbing Tang Prof. Wenjun Zhang Prof. Chun‐Sing Lee 《化学:亚洲杂志》2015,10(7):1490-1495
Composition engineering is an important approach for modulating the physical properties of alloyed semiconductors. In this work, ternary CuSxSe1?x nanoplates over the entire composition range of 0≤x≤1 have been controllably synthesized by means of a simple aqueous solution method at low temperature (90 °C). Reaction of Cu2+ cations with polysulfide/‐selenide ((SnSem)2?) anions rather than independent Sn2? and Sem2? anions is responsible for the low‐temperature and rapid synthesis of CuSxSe1?x alloys, and leads to higher S/Se ratios in the alloys than that in reactants owing to different dissociation energies of the Se?Se and the S?S bonds. The lattice parameters ‘a’ and ‘c’ of the hexagonal CuSxSe1?x alloys decrease linearly, whereas the direct bandgaps increase quadratically along with the S content. Direct bandgaps of the alloys can be tuned over a wide range from 1.64 to 2.19 eV. Raman peaks of the S?Se stretching mode are observed, thus further confirming formation of the alloyed CuSxSe1?x phase. 相似文献
3.
Eric Gottlieb Dr. Huifeng Qian Prof. Dr. Rongchao Jin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(13):4238-4243
Atomically precise alloying and de‐alloying processes for the formation of Ag–Au and Cu–Au nanoparticles of 25‐metal‐atom composition (referred to as AgxAu25?x(SR)18 and CuxAu25?x(SR)18, in which R=CH2CH2Ph) are reported. The identities of the particles were determined by matrix‐assisted laser desorption ionization mass spectroscopy (MALDI‐MS). Their structures were probed by fragmentation analysis in MALDI‐MS and comparison with the icosahedral structure of the homogold Au25(SR)18 nanoparticles (an icosahedral Au13 core protected by a shell of Au12(SR)18). The Cu and Ag atoms were found to preferentially occupy the 13‐atom icosahedral sites, instead of the exterior shell. The number of Ag atoms in AgxAu25?x(SR)18 (x=0–8) was dependent on the molar ratio of AgI/AuIII precursors in the synthesis, whereas the number of Cu atoms in CuxAu25?x(SR)18 (x=0–4) was independent of the molar ratio of CuII/AuIII precursors applied. Interestingly, the CuxAu25?x(SR)18 nanoparticles show a spontaneous de‐alloying process over time, and the initially formed CuxAu25?x(SR)18 nanoparticles were converted to pure Au25(SR)18. This de‐alloying process was not observed in the case of alloyed AgxAu25?x(SR)18 nanoparticles. This contrast can be attributed to the stability difference between CuxAu25?x(SR)18 and AgxAu25?x(SR)18 nanoparticles. These alloyed nanoparticles are promising candidates for applications such as catalysis. 相似文献
4.
Dr. Leela S. Panchakarla Dr. Ronit Popovitz‐Biro Dr. Lothar Houben Prof. Rafal E. Dunin‐Borkowski Prof. Reshef Tenne 《Angewandte Chemie (International ed. in English)》2014,53(27):6920-6924
The synthesis of nanotubes from layered compounds has generated substantial scientific interest. “Misfit” layered compounds (MLCs) of the general formula [(MX)1+x]m[TX2]n, where M can include Pb, Sb, rare earths; T=Cr, Nb, and X=S, Se can form layered structures, even though each sub‐system alone is not necessarily a layered or a stable compound. A simple chemical method is used to synthesize these complex nanotubes from lanthanide‐based misfit compounds. Quaternary nanotubular structures formed by partial substitution of the lanthanide atom in nanotubes by other elements are also confirmed. The driving force and mechanism of formation of these nanotubes is investigated by systematic temperature and time‐dependent studies. A stress‐inducement mechanism is proposed to explain the formation of the nanotubes. The resulting materials may find applications in fields that include thermoelectrics, light emitters, and catalysis and address fundamental physical issues in low dimensions. 相似文献
5.
Prof. Dr. Holger Braunschweig Marco Fuß Dr. Swagat K. Mohapatra Katharina Kraft Dr. Thomas Kupfer Melanie Lang Dr. Krzysztof Radacki Dr. Constantin G. Daniliuc Prof. Dr. Peter G. Jones Prof. Dr. Matthias Tamm 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(38):11732-11743
A novel one‐pot method was developed for the preparation of [Ti(η5‐C5H5)(η7‐C7H7)] (troticene, 1 ) by reaction of sodium cyclopentadienide (NaCp) with [TiCl4(thf)2], followed by reduction of the intermediate [(η5‐C5H5)2TiCl2] with magnesium in the presence of cycloheptatriene (C7H8). The [n]troticenophanes 3 (n=1), 4 , 8 , 10 (n=2), and 11 (n=3) were synthesized by salt elimination reactions between dilithiated troticene, [Ti(η5‐C5H4Li)(η7‐C7H6Li)] ? pmdta ( 2 ) (pmdta=N,N′,N′,N′′,N′′‐pentamethyldiethylenetriamine), and the appropriate organoelement dichlorides Cl2Sn(Mes)2 (Mes=2,4,6‐trimethylphenyl), Cl2Sn2(tBu)4, Cl2B2(NMe2)2, Cl2Si2Me4, and (ClSiMe2)2CH2, respectively. Their structural characterization was carried out by single‐crystal X‐ray diffraction and multinuclear NMR spectroscopy. The stanna[1]‐ and stanna[2]troticenophanes 3 and 4 represent the first heteroleptic sandwich complexes bearing Sn atoms in the ansa bridge. The reaction of 3 with [Pt(PEt3)3] resulted in regioselective insertion of the [Pt(PEt3)2] fragment into the Sn? Cipso bond between the tin atom and the seven‐membered ring, which afforded the platinastanna[2]troticenophane 5 . Oxidative addition was also observed upon treatment of 4 with elemental sulfur or selenium, to produce the [3]troticenophanes [Ti(η5‐C5H4SntBu2)(η7‐C7H6SntBu2)E] ( 6 : E=S; 7 : E=Se). The B? B bond of the bora[2]troticenophane 8 was readily cleaved by reaction with [Pt(PEt3)3] to form the corresponding oxidative addition product [Ti(η5‐C5H4BNMe2)(η7‐C7H6BNMe2)Pt(PEt3)2] ( 9 ). The solid‐state structures of compounds 5 , 6 , and 9 were also determined by single‐crystal X‐ray diffraction. 相似文献
6.
Lin Huang Jiasui Zou Jin‐Yu Ye Zhi‐You Zhou Zhang Lin Xiongwu Kang Prashant K. Jain Shaowei Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(26):8886-8890
Localized surface plasmon resonance (LSPR) excitation of noble metal nanoparticles has been shown to accelerate and drive photochemical reactions. Here, LSPR excitation is shown to enhance the electrocatalysis of a fuel‐cell‐relevant reaction. The electrocatalyst consists of PdxAg alloy nanotubes (NTs), which combine the catalytic activity of Pd toward the methanol oxidation reaction (MOR) and the visible‐light plasmonic response of Ag. The alloy electrocatalyst exhibits enhanced MOR activity under LSPR excitation with significantly higher current densities and a shift to more positive potentials. The modulation of MOR activity is ascribed primarily to hot holes generated by LSPR excitation of the PdxAg NTs. 相似文献
7.
Krishnendu Maji Paribesh Acharyya Pragnya Satapathy S. Krishna Prasad Kanishka Biswas 《化学:亚洲杂志》2019,14(24):4641-4644
Thermochromic materials are generally synthesized via high‐temperature melting reaction or solution‐based synthesis. Herein, all‐inorganic thermochromic compounds of (Ag1?xCux)2HgI4 were synthesized by solvent‐free simple and scalable mechanochemical grinding at room temperature. Temperature‐dependent electronic absorption spectroscopy along with DSC analysis confirmed the thermochromic events within these materials, and the phase transition temperature varied with solid solution compositions. The photoluminescence (PL) spectra is red‐shifted with the increase in the Cu content in (Ag1?xCux)2HgI4 (x=0–1). 相似文献
8.
Stable ‐ESiMe3 Complexes of CuI and AgI (E=S,Se) with NHCs: Synthons in Ternary Nanocluster Assembly 下载免费PDF全文
Mahmood Azizpoor Fard Tetyana I. Levchenko Carolyn Cadogan William J. Humenny Prof. Dr. John F. Corrigan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(13):4543-4550
As a part of efforts to prepare new “metallachalcogenolate” precursors and develop their chemistry for the formation of ternary mixed‐metal chalcogenide nanoclusters, two sets of thermally stable, N‐heterocyclic carbene metal–chalcogenolate complexes of the general formula [(IPr)Ag?ESiMe3] (IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene; E=S, 1 ; Se, 2 ) and [(iPr2‐bimy)Cu?ESiMe3]2 (iPr2‐bimy=1,3‐diisopropylbenzimidazolin‐2‐ylidene; E=S, 4 ; Se, 5 ) are reported. These are prepared from the reaction between the corresponding carbene metal acetate, [(IPr)AgOAc] and [(iPr‐bimy)CuOAc] respectively, and E(SiMe3)2 at low temperature. The reaction of [(IPr)Ag?ESiMe3] 1 with mercury(II) acetate affords the heterometallic complex [{(IPr)AgS}2Hg] 3 containing two (IPr)Ag?S? fragments bonded to a central HgII, representing a mixed mercury–silver sulfide complex. The reaction of [(iPr2‐bimy)Cu‐SSiMe3]2, which contains a smaller N‐heterocyclic‐carbene, with mercuric(II) acetate affords the high nuclearity cluster, [(iPr2‐bimy)6Cu10S8Hg3] 6 . The new N‐heterocyclic carbene metal–chalcogenolate complexes 1 , 2 , 4 , 5 and the ternary mixed‐metal chalcogenolate complex 3 and cluster 6 have been characterized by multinuclear NMR spectroscopy (1H and 13C), elemental analysis and single‐crystal X‐ray diffraction. 相似文献
9.
Jinsong Chai Sha Yang Ying Lv Hanbao Chong Haizhu Yu Manzhou Zhu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(44):15818-15821
Bimetallic nanomaterials are of major importance in catalysis. A Au‐Cu bimetallic nanocluster was synthesized that is effective in catalyzing the epoxide ring‐opening reaction. The catalyst was analyzed by SCXRD and ESI‐MS and found to be Au24Cu6(SPhtBu)22 (Au24Cu6 for short). Six copper atoms exclusively occupy the surface positions in two groups with three atoms for each, and each group was bonded with three thiolate ligands to give a planar motif reminiscent of a benzene ring. In the epoxide‐ring opening reaction, Au24Cu6 exhibited superior catalytic activity compared to other homometallic and Au‐Cu alloy NCs, such as Au25 and Au38?xCux. Control experiments and DFT calculations revealed that the π conjugation among the Cu?S bonds played a pivotal role. This study demonstrates a unique π conjugation established among the Cu?S bonds as a critical structural motif in the nanocluster, which facilitates the catalysis of a ring‐opening reaction. 相似文献
10.
Progna Banerjee Prof. Prashant K. Jain 《Angewandte Chemie (International ed. in English)》2018,57(30):9315-9319
The search for ion‐conductive solid electrolytes for Li+ batteries is an important scientific and technological challenge with economic and sustainable energy implications. In this study, nanocrystals (NCs) of the ion conductor copper selenide (Cu2?ySe) were doped with Li by the process of cation exchange. Li2xCu2?2xSe alloy NCs were formed at intermediate stages of the reaction, which was followed by phase segregation into Li2Se and Cu2Se domains. Li‐doped Cu2?ySe NCs and Li2Se NCs exhibit a possible SI phase at moderately elevated temperatures and warrant further ion‐conductance tests. These findings may guide the design of nanostructured super‐ionic electrolytes for Li+ transport. 相似文献
11.
Influence of Cyclopentadienyl Ring‐Tilt on Electron‐Transfer Reactions: Redox‐Induced Reactivity of Strained [2] and [3]Ruthenocenophanes 下载免费PDF全文
Dr. Andrew D. Russell Prof. Joe B. Gilroy Prof. Kevin Lam Dr. Mairi F. Haddow Prof. Jeremy N. Harvey Prof. William E. Geiger Prof. Ian Manners 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(49):16216-16227
In contrast to ruthenocene [Ru(η5‐C5H5)2] and dimethylruthenocene [Ru(η5‐C5H4Me)2] ( 7 ), chemical oxidation of highly strained, ring‐tilted [2]ruthenocenophane [Ru(η5‐C5H4)2(CH2)2] ( 5 ) and slightly strained [3]ruthenocenophane [Ru(η5‐C5H4)2(CH2)3] ( 6 ) with cationic oxidants containing the non‐coordinating [B(C6F5)4]? anion was found to afford stable and isolable metal?metal bonded dicationic dimer salts [Ru(η5‐C5H4)2(CH2)2]2[B(C6F5)4]2 ( 8 ) and [Ru(η5‐C5H4)2(CH2)3]2[B(C6F5)4]2 ( 17 ), respectively. Cyclic voltammetry and DFT studies indicated that the oxidation potential, propensity for dimerization, and strength of the resulting Ru?Ru bond is strongly dependent on the degree of tilt present in 5 and 6 and thereby degree of exposure of the Ru center. Cleavage of the Ru?Ru bond in 8 was achieved through reaction with the radical source [(CH3)2NC(S)S?SC(S)N(CH3)2] (thiram), affording unusual dimer [(CH3)2NCS2Ru(η5‐C5H4)(η3‐C5H4)C2H4]2[B(C6F5)4]2 ( 9 ) through a haptotropic η5–η3 ring‐slippage followed by an apparent [2+2] cyclodimerization of the cyclopentadienyl ligand. Analogs of possible intermediates in the reaction pathway [C6H5ERu(η5‐C5H4)2C2H4][B(C6F5)4] [E=S ( 15 ) or Se ( 16 )] were synthesized through reaction of 8 with C6H5E?EC6H5 (E=S or Se). 相似文献
12.
Integration of Semiconducting Sulfides for Full‐Spectrum Solar Energy Absorption and Efficient Charge Separation 下载免费PDF全文
Tao‐Tao Zhuang Yan Liu Yi Li Yuan Zhao Liang Wu Prof. Dr. Jun Jiang Prof. Dr. Shu‐Hong Yu 《Angewandte Chemie (International ed. in English)》2016,55(22):6396-6400
The full harvest of solar energy by semiconductors requires a material that simultaneously absorbs across the whole solar spectrum and collects photogenerated electrons and holes separately. The stepwise integration of three semiconducting sulfides, namely ZnS, CdS, and Cu2?xS, into a single nanocrystal, led to a unique ternary multi‐node sheath ZnS–CdS–Cu2?xS heteronanorod for full‐spectrum solar energy absorption. Localized surface plasmon resonance (LSPR) in the nonstoichiometric copper sulfide nanostructures enables effective NIR absorption. More significantly, the construction of pn heterojunctions between Cu2?xS and CdS leads to staggered gaps, as confirmed by first‐principles simulations. This band alignment causes effective electron–hole separation in the ternary system and hence enables efficient solar energy conversion. 相似文献
13.
Dr. Jinbao Zhu Qiuyang Li Liangfei Bai Yongfu Sun Min Zhou Prof. Yi Xie 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(41):13213-13221
Despite the promising applications of copper selenide nanoparticles, an in‐depth elucidation of the inherent properties of tetragonal Cu2Se (β‐Cu2Se) has not been performed because of the lack of a facile synthesis on the nanoscale and an energy‐intensive strategy is usually employed. In this work, a facile wet‐chemical strategy, employing HCOOH as reducing agent, has been developed to access single‐crystalline metastable β‐Cu2Se hyperbranched architectures for the first time. The process avoids hazardous chemistry and high temperatures, and thus opens up a facile approach to the large‐scale low‐cost preparation of metastable β‐Cu2Se hyperbranched architectures. A possible growth mechanism to explain the formation of the β‐Cu2Se dendritic morphology has been proposed based on time‐dependent shape evolution. Further investigations revealed that the metastable β‐Cu2Se can convert into the thermodynamically more stable cubic α‐Cu2?xSe maintaining the dendritic morphology. An increase in electrical conductivity and a tunable optical response were observed under ambient conditions. This behavior can be explained by the oxidation of the surface of the β‐Cu2Se hyperbranched structures, ultimately leading to solid‐state phase conversion from β‐Cu2Se into superionic conductor α‐Cu1.8Se, which has potential applications in energy‐related devices and sensors. 相似文献
14.
Chalcogen Derivatives of the Halfsandwich Tungsten(V) Complexes Cp*WCl4 and Cp*WCl4(PMe3). X‐Ray Crystal Structure Analyses of anti ‐[Cp*W(Se)(μ‐Se)]2 and Cp*W(S)2(OMe) The chalcogenation of Cp*WCl4 ( 1 ) by E(SiMe3)2 (E = S, Se) and Te(SiMe2tBu)2 in chloroform solution leads to dimeric products of the type anti‐[Cp*W(E)(μ‐E)]2 (E = S ( 3 a ), Se ( 3 b ) and Te ( 3 c )). An X‐ray structure determination of 3 b indicates a centrosymmetric molecule containing a planar W(μ‐Se)2W ring, the W–W distance (297.9(1) pm) corresponds to a single bond. In the presence of air the two terminal chalcogenido ligands (E) in 3 a – c are stepwise replaced by oxido ligands (O) to give [Cp*W(O)(μ‐E)]2 (E = S ( 5 a ), Se ( 5 b ) and Te ( 5 c )) in quantitative yields. The reaction of Cp*WCl4 with H2S or ammonium polysulfide, (NH4)2Sx (x ∼ 10), leads to Cp*W(S)2Cl ( 6 a ); the corresponding methoxy derivative, Cp*W(S)2OCH3 ( 9 a ), has been characterized by an X‐ray structure analysis. On the other hand, the reaction of Cp*WCl4(PMe3) ( 2 ) with sodium tetrasulfide, Na2S4, in dimethylformamide solution gives a mixture of mononuclear Cp*W(S)(S2)Cl ( 8 a ), dinuclear [Cp*W(S)(μ‐S)]2 ( 3 a ) and a trinuclear side‐product of composition Cp*2W3S7 ( 13 a ). Terminal sulfido ligands are replaced by terminal oxido ligands in solution in the presence of oxygen. Thus, 6 a is stepwise converted into Cp*W(O)(S)Cl ( 10 a ) and CpW(O)2Cl ( 12 a ), whereas 8 a gives Cp*W(O)(S2)Cl ( 11 a ) and 13 a leads to Cp*2W3(O)S6 ( 14 a ). The disulfido complexes 8 a and 11 a are desulfurized by triphenylphosphane to give 6 a and 10 a . The new complexes have been characterized by their IR and NMR spectra and by mass spectrometry. 相似文献
15.
In this work, we develop a low‐temperature, facile solution reaction route for the fabrication of quantum‐dot‐sensitized solar cells (QDSSCs) containing Ag2S‐ZnO nanowires (NWs), simultaneously ensuring low manufacturing costs and environmental safety. For comparison, a CdS‐ZnO NW photoanode was also prepared using the layer‐by‐layer growth method. Ultraviolet photoelectron spectroscopy analysis revealed type‐II band alignments for the band structures of both photoanodes which facilitate electron transfer/collection. Compared to CdS‐ZnO QDSSCs, Ag2S‐ZnO QDSSCs exhibit a considerably higher short‐circuit current density (Jsc) and a strongly enhanced light‐harvesting efficiency, but lower open‐circuit voltages (Voc), resulting in almost the same power‐conversion efficiency of 1.2 %. Through this work, we demonstrate Ag2S as an efficient quantum‐dot‐sensitizing material that has the potential to replace Cd‐based sensitizers for eco‐friendly applications. 相似文献
16.
Two‐Dimensional CuSe Nanosheets with Microscale Lateral Size: Synthesis and Template‐Assisted Phase Transformation 下载免费PDF全文
Dr. Xue‐Jun Wu Dr. Xiao Huang Dr. Juqing Liu Dr. Hai Li Jian Yang Dr. Bing Li Prof. Dr. Wei Huang Prof. Dr. Hua Zhang 《Angewandte Chemie (International ed. in English)》2014,53(20):5083-5087
Semiconducting nanosheets with microscale lateral size are attractive building blocks for the fabrication of electronic and optoelectronic devices. The phase‐controlled chemical synthesis of semiconducting nanosheets is of particular interest, because their intriguing properties are not only related to their size and shape, but also phase‐dependent. Herein, a facile method for the synthesis of phase‐pure, microsized, two‐dimensional (2D) CuSe nanosheets with an average thickness of approximately 5 nm is demonstrated. These hexagonal‐phased CuSe nanosheets were transformed into cubic‐phased Cu2?xSe nanosheets with the same morphology simply by treatment with heat in the presence of CuI cations. The phase transformation, proposed to be a template‐assisted process, can be extended to other systems, such as CuS and Cu1.97S nanoplates. Our study offers a new method for the phase‐controlled preparation of 2D nanomaterials, which are not readily accessible by conventional wet‐chemical methods. 相似文献
17.
J.Matias Reinoso Hans‐Joachim Muhr Frank Krumeich Fabian Bieri Reinhard Nesper 《Helvetica chimica acta》2000,83(8):1724-1733
Vanadium oxide nanotubes (Cn‐VOx‐NTs) contain α‐monoamines (CnH2n+1NH2 with 4≤n≤22) as templates intercalated between crystalline VOx layers comprising multilayer tube walls. The present study reveals that a large proportion of the amines can easily be exchanged by metal cations. The tubular morphology is not affected by this reaction, but the distance between the VOx layers, i.e., 2.8 nm in C12‐VOxNTs, decreases in the reaction product to 0.9 – 1.2 nm, depending on the metal salt actually applied. Alkali (Na+, K+), alkaline‐earth (Mg2+, Ca2+, Sr2+), and transition‐metal salts (Fe2+, Co2+, Ni2+, Cu2+) have successfully been intercalated. This reaction is partly reversible since intercalated sodium cations can be resubstituted by dodecylamine. This exchange produces again C12‐VOx‐NTs with the original inter‐layer spacing. However, this release is successful only when sodium is complexed by a crown ether. Under these reaction conditions, even a cyclic uptake and release of Na+ and amine, respectively, accompanied by a corresponding shrinkage and widening of the inter‐layer distance, is observed while the tubular structure is widely preserved. Furthermore, a distinct selectivity of the metal‐cation exchange has been observed. 相似文献
18.
George E. Cutsail Nicole L. Gagnon Andrew D. Spaeth William B. Tolman Serena DeBeer 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9212-9217
Valence‐to‐Core (VtC) X‐ray emission spectroscopy (XES) was used to directly detect the presence of an O?O bond in a complex comprising the [CuII2(μ‐η2:η2‐O2)]2+ core relative to its isomer with a cleaved O?O bond having a [CuIII2(μ‐O)2]2+ unit. The experimental studies are complemented by DFT calculations, which show that the unique VtC XES feature of the [CuII2(μ‐η2:η2‐O2)]2+ core corresponds to the copper stabilized in‐plane 2p π peroxo molecular orbital. These calculations illustrate the sensitivity of VtC XES for probing the extent of O?O bond activation in μ‐η2:η2‐O2 species and highlight the potential of this method for time‐resolved studies of reaction mechanisms. 相似文献
19.
Dipak Kumar Roy Dr. Shubhankar Kumar Bose K. Geetharani Kiran Kumar Varma Chakrahari Dr. Shaikh M. Mobin Dr. Sundargopal Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(32):9983-9991
The reaction of [CpnMCl4?x] (M=V: n=2, x=2; M=Nb: n=1, x=0; Cp=η5‐C5H5) with LiBH4 ? THF followed by thermolysis in the presence of dichalcogenide ligands E2R2 (E=S, Te; R=2,6‐(tBu)2‐C6H2OH, Ph) and 2‐mercaptobenzothiazole (C7H5NS2) yielded dimetallaheteroboranes [{CpV(μ‐TePh)}2(μ3‐Te)BH ? thf] ( 1 ), [(CpV)2(BH3S)2] ( 2 ), [(CpNb)2B4H10S] ( 3 ), [(CpNb)2B4H11S(tBu)2C6H2OH] ( 4 ), and [(CpNb)2B4H11TePh] ( 5 ). In cluster 1 , the V2BTe atoms define a tetrahedral framework in which the boron atom is linked to a THF molecule. Compound 2 can be described as a dimetallathiaborane that is built from two edge‐fused V2BS tetrahedron clusters. Cluster 3 can be considered as an edge‐fused cluster in which a trigonal‐bipyramidal unit (Nb2B2S) has been fused with a tetrahedral core (Nb2B2) by means of a common Nb2 edge. In addition, thermolysis of an in‐situ‐generated intermediate that was produced from the reaction of [Cp2VCl2] and LiBH4 ? THF with excess BH3 ? THF yielded oxavanadaborane [(CpV)2B3H8(μ3‐OEt)] ( 6 ) and divanadaborane cluster [(CpV)2B5H11] ( 7 ). Cluster 7 exhibits a nido geometry with C2v symmetry and it is isostructural with [(Cp*M)2B5H9+n] (M=Cr, Mo, and W, n=0; M=Ta, n=2; Cp*=η5‐C5Me5). All of these new compounds have been characterized by 1H NMR, 11B NMR, and 13C NMR spectroscopy and elemental analysis and the structural types were established unequivocally by crystallographic analysis of compounds 1 – 4 , 6 , and 7 . 相似文献
20.
Dr. Zhi‐Da Gao Jing Guo Dr. Nabeen K Shrestha Robert Hahn Prof. Yan‐Yan Song Prof. Patrik Schmuki 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(46):15530-15534
Semi‐metallic TiO2 nanotube arrays (TiOxCy NTs) have been decorated uniformly with Ni(OH)2 nanoparticles without the aid of a polymer binder. The resulting hybrid nanotube arrays exhibit excellent catalytic activity towards non‐enzymatic glucose electro‐oxidation. The anodic current density of the glucose oxidation is significantly improved compared with traditional TiO2 nanotubes decorated with Ni(OH)2. Moreover, the Ni(OH)2/TiOxCy NT‐based electrode shows a fast response, high sensitivity, wide linear range, good selectivity and stability towards glucose electro‐oxidation, and thus provides a promising and cost‐effective sensing platform for non‐enzymatic glucose detection. 相似文献