Sökresultat

Filtyp

Din sökning på "*" gav 565765 sökträffar

No title

In situ X-ray absorption spectroscopy (XAS) investigations have been performed to provide insights into the reaction mechanism of a palladium(ii) catalyzed undirected C-H acetoxylation reaction in the presence of an oxidant. A Pd(ii) N-heterocyclic carbene complex π-stacked onto reduced graphene oxide (rGO) was used as the catalyst. The Pd speciation during the catalytic process was examined by XA

No title

A systematic study of the photophysical and electrochemical properties of triscyclometalated homoleptic iridium(III) complexes based on 2-(1-naphthyl)pyridine (npy) ligands is presented. A systematic investigation of ligand substitution patterns showed an influence on the lifetime of the excited state, with slight changes in the absorption

No title

A series of complexes with oxathiacrown ethers appended to a [Ru(bpy)2]2+ moiety have been synthesized and characterised using 1H NMR, 13C NMR, IR, electronic absorption and emission spectroscopies, mass spectrometry and elemental analyses. The complexes exhibit strong MLCT luminescence bands in the range 608-611 nm and one reversible metal centred oxidation potential in the range 1.00-1.02 V. The

No title

Metalation of two cyclohexane-based phosphinite pincer ligands, cis-POCyPO (4) and trans-POCyPO (5) (POCyPO = {1,3-bis-[(di-tert-butylphosphinito]cyclohexane}−), is reported. In line with previously published results (Dalton Trans. 2009, 8626, DOI: 10.1039/B910798C), ligand 4 undergoes aromatization to give benzene-based complex (POCOP)IrHCl (3) at high temperatures in the presence of [Ir(COD)Cl]2

No title

The ligand Ph2PC6H4(CH2N(Me)CO(Et)) reacts with (bis(diphenylphosphino)butane) (2,5-norbornadiene)rhodium tetrafluoroborate (2a) and (bis(diphenylphosphino)ethane)(2,5-norbornadiene) rhodium tetrafluoroborate (2b) at room temperature in the presence of hydrogen to displace the norbornadiene and give the chelate complexes 3a,b, in which the phosphorus and the oxygen atoms are coordinated to give an

No title

Treatment of 2 equiv. of a mixture of the diphosphite cis, trans-1,3-(iPr2PO)2C6H 10 with [Pd(CO2CF3)2] and sequential addition of an excess of NaI gives the binuclear 16-atom ring chelate complex trans-[Pd2I4{cis-(iPr2PO) 2C6H10}2] (1) and the mononuclear complex cis-[PdI2{cis-(iPr2PO)2C 6H10}] (2) exclusively. NMR spectroscopy and X-ray crystallography have unambiguously determined the structure

No title

The reaction between trans-PtPhCl(SMe2)2 and (R,R)-CHIRAPHOS gives cis-[PtPhCl((R,R)-CHIRAPHOS)] (1). The crystals of which are monoclinic, space group P21 with a = 12.875(3), b = 18.012(4), c = 13.864(3) Å, β = 109.71(3)° and Z = 4. In CDCl3 1 reacts with Ph2P(C6H4)CH2N(Me)(COEt) to give cis[PtCl2((R,R)-CHIRAPHOS)] (2), the crystals of which are monoclinic, space group P21 with a = 7.8052(16), b

No title

Within cognitive science, narratives are regarded as crucial and fundamental cognitive instruments or tools. As Roger Schank suggests, the identity of (sub-)cultures is to a considerable extent based upon the sharing of narrative structures (Schank. 1995. Tell me a story: Narrative and intelligence. Evanston, IL: Northwestern University Press.). According to Schank, culturally shared stories, as d

No title

We developed a spectro-electrochemical cell for X-ray absorption and X-ray emission spectroscopy, which are element-specific methods to study local electronic structures in the soft X-ray region. In the usual electrochemical measurement setup, the electrode is placed in solution, and the surface/interface region of the electrode is not normally accessible by soft X-rays that have low penetration d

No title

The valence electronic structures of the amino acid glycine in aqueous solution were investigated in detail through X-ray emission spectroscopy at O 1s excitation under selective excitation conditions of the C[double bond, length as m-dash]O site in the carboxyl group. The X-ray emission spectra of glycine were similar to that of acetic acid (CH3COOH), suggesting a resemblance between the molecula

No title

Quantifying net CO2 exchange (NEE) of arctic terrestrial ecosystems in response to changes in climatic and environmental conditions is central to understanding ecosystem functioning and assessing potential feedbacks of the carbon cycle to future climate changes. However, annual CO2 budgets for arctic tundra are rare due to the difficulties of performing measurements during non-growing seasons. It

No title

In cold/arid agricultural regions seasonal freezing/thawing of soils can result in soil salinization in winter; therefore, it is crucial to understand the mechanisms behind soil salinization during winter for better water management in agriculture. In Hetao Irrigation District of Inner Mongolia, northern China, we used the CoupModel (version 5) considering dynamical impacts of salt on soil freezin