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61.
Reaction of N-(2′-hydroxyphenyl)-4-R-benzaldimines (L-R, R = OCH3, CH3, H, Cl and NO2) with [Os(PPh3)3Br2] in refluxing 2-methoxyethanol in the presence of triethylamine affords two families of organoosmium complexes (1-R and 2-R). In both 1-R and 2-R complexes a benzaldimine ligand is coordinated to the metal center as tridentate C,N,O-donor. In the 1-R complexes, a bidentate N,O-donor imionsemiquinonate ligand, derived from the hydrolysis of another benzaldimine, and a PPh3 ligand are also coordinated to osmium. In the 2-R complexes, a carbonyl, derived from decarbonylation of 4-R-benzaldehyde (derived from the same hydrolysis stated above), and two PPh3 ligands take up the remaining coordination sites on osmium. Structures of the 1-Cl and 2-OCH3 complexes have been determined by X-ray crystallography. All the 1-R and 2-R complexes are diamagnetic, and show characteristic 1H NMR signals and intense MLCT transitions in the visible region. Cyclic voltammetry on the 1-R complexes shows a reversible Os(III)-Os(IV) oxidation within 0.47-0.67 V (vs SCE), followed by an irreversible oxidation of the imionsemiquinonate ligand within 1.10-1.36 V. An irreversible Os(III)-Os(II) reduction is also displayed by the 1-R complexes within −1.02 to −1.14 V. Cyclic voltammetry on the 2-R complexes shows a reversible Os(II)-Os(III) oxidation within 0.29-0.51 V, followed by a quasi-reversible oxidation within 1.04-1.29 V, and an irreversible reduction of the coordinated benzaldimine ligand within −1.16 to −1.31 V. 相似文献
62.
We discuss congruences of p-algebras. We characterize kernel ideals of a p-algebra. Indeed, we show that an ideal of a p-algebra is a p-ideal if and only if it is a kernel ideal. We study cokernel filters of a p-algebra. We construct a class of p-algebras in which every cokernel filter is a p-filter. We also give some characterizations of Boolean congruences of a p-algebra. 相似文献
63.
K.S. Subrahmanyam Prashant Kumar Angshuman Nag C.N.R. Rao 《Solid State Communications》2010,150(37-38):1774-1777
It has been demonstrated that acid-treated graphene samples as well as reduced graphene oxide show fairly intense blue emission centered around 440 nm. Reduction of graphene oxide can be carried out either chemically or by using different types of radiations. Blue emission from graphene-based materials can be combined with the yellow emission from materials like ZnO to produce white light sources. 相似文献
64.
Rare earth cobalties, LnCoO3, can be conveniently prepared by the thermal decomposition of the precursor LnCo(C2O4)3·nH2O (La, Ce, n=9; Pr, Nd, n=8). CeCo(C2O4)3·8H2O, unlike the other oxalato compounds thermally decompose to a mixture of CeO2 and Co3O4. Although LnCoO3are formed from the precursors at a temperature lower than 800°C, thermal analysis of a mixture of La2(C2O4)3·10H2O and CoC2O4·2H2O at 900·C shows the residue containing mainly La2O3 and Co3O4 with a small amount of LaCoO3. 相似文献
65.
N. K. Nag R. Mukhopadhyay K. De Sadhan S. Basu 《Journal of Thermal Analysis and Calorimetry》1976,9(3):395-400
Thermal characteristics of the composites of poly(methyl methacrylate) and copper are reported, including the order of reaction and activation energy of the major second stage of pyrolysis. The randomly-distributed metal particles in the polymer matrix can form paths for heat transfer which determine the mechanism of thermal degradation.
Zusammenfassung Die thermischen Charakteristika der Verbindungen von Polymethylmethacrylat mit Kupfer werden zusammen mit der Reaktionsordnung und der Aktivierungsenergie der grösseren zweiten Stufe der Pyrolyse beschrieben. Die zufallsbestimmt verteilten Metallpartikel in der Polymermatrix können Wege des Wärmetransfers formen, welche den Mechanismus der thermischen Zersetzung bestimmen.
Résumé On décrit les caractéristiques thermiques de composites du polyméthylméthacrylate avec le cuivre, parmi lesquelles l'ordre de réaction et l'énergie d'activation de la seconde étape de la pyrolyse qui est la principale. Les particules du métal distribuées au hasard dans la matrice du polymère peuvent constituer des voies pour le transfert de chaleur qui déterminent le mécanisme de la dégradation thermique.
, . , .相似文献
66.
J W Cubbage T A Tetzlaff H Groundwater R D McCulla M Nag W S Jenks 《The Journal of organic chemistry》2001,66(25):8621-8628
Photolysis of aromatic sulfoxides in the presence of alkoxides in alcoholic solvents provides a photochemical route to the corresponding sulfides. Other electron donors also give sulfide with various degrees of success. The reaction could also be carried out using carbazoles as sensitizers, and quantitative yields could be obtained using N-methylcarbazole in methanol. Evidence points toward a hydroxysulfuranyl radical as the key intermediate, and solvent effects point to heterolysis, rather than homolysis, as the step that breaks the S-O bond. 相似文献
67.
A scheme for studyingq deformed quasi exactly solvable problem has been applied to the Schrödinger Hulthen problem (l=0). It is found that for the confined Hulthen problem, the confining parameter can be related to the deformation parameterq. 相似文献
68.
[reaction: see text] The reductive coupling of substituted alpha-iodomethyloxazoles and thiazoles with aliphatic aldehydes under Barbier conditions provides an effective method for the direct incorporation of intact heterocyclic systems. 相似文献
69.
The parallel and transverse components of diffusion constants of electrons in CdTe have been computed for fields of 30, 40, and 50 kV/cm using the Monte Carlo method. Results are presented for the velocity autocorrelation function and for the ac diffusion constants for two models of energy band structure and scattering constants, used earlier in the literature. The diffusion constants as obtained from the two models are significantly different, but none are in agreement with the available experimental results. 相似文献
70.
Quinoxaline-2-carboxylic acid and 3-chloro and 3-hydroxy derivatives have been studied as analytical reagents. The solubility products of the metal salts, the optimum pH range for complete precipitation and the thermal behaviours of the metal complexes have been established. Quinoxaline-2-carboxylic acid allows the gravimetric determination of Cu(II), Cd(II), Zn(II), Co(II), Ni(II) and Pd(II); with the 3-chloro and 3-hydroxy derivatives, only palladium(II) could be precipitated quantitatively. 相似文献