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1.
Sessler JL Tomat E Mody TD Lynch VM Veauthier JM Mirsaidov U Markert JT 《Inorganic chemistry》2005,44(7):2125-2127
The coordination chemistry of the Schiff base polypyrrolic octaaza macrocycle 1 toward late first-row transition metals was investigated. Binuclear complexes with the divalent cations Ni(II), Cu(II), and Zn(II) and with the monovalent cation Cu(I) were prepared and characterized. Air oxidation of the Cu(I) ions in the latter complex to their divalent oxidation state resulted in a change in the coordination mode relative to the macrocycle. 相似文献
2.
Venugopal D. V. R. Karteek Rao Amperayani Uma Devi Parimi Sastry Y. N. Aruna Lakshmi K. Tarak Ramji M. Shiralgi Y. 《Research on Chemical Intermediates》2017,43(10):5755-5778
Research on Chemical Intermediates - Antibiotic-resistant penicillin binding protein (PBPs) production is one of the reasons why bacteria develop resistance to β-lactam antibiotics, and this... 相似文献
3.
The thermolysis of t-butyl perpent-4-enoate in ketones leads to the formation of 5-(α-alkanonyl) and 5-(α-cyclanonyl)-4-pentanolides with fairly good yields. 相似文献
4.
Tarak Saied Nourchaine Jelaiel Mohamed Lotfi Efrit Yves Fort Corinne Comoy 《Tetrahedron》2017,73(11):1489-1494
We report herein a short and efficient synthesis of benz[e][1,2,4]- or [d][1,2,6]oxadiazepines and benzo[f][1,3,5]triazocines from easily prepared N-aryl iminoesters. The strategy involves a bis-nucleophile reagent (hydroxylamine or guanidine) that promotes a one-step ring closure from the starting functionalized iminoesters. 相似文献
5.
We report a new synthesis and our study of the mechanism of formation of substituted 1-trifluoromethyl and 1-perfluoroalkyl-3-(phenylamino)prop-2-en-1-one starting from 3-(R-phenoxy)-3-perfluoroalkyl-prop-2-enals and arylamines. Reactivity study of the intermediates confirmed that 3-perfluoroalkyl-N,N′-diphenyl-1,5-diazapentadienes are the synthetic intermediates of the synthesis of 2-perfluoroalkylquinolines. The mechanism of the reaction of 1-trifluoromethyl and 1-perfluoroalkyl-3-(phenylamino)prop-2-en-1-one with POCl3 was studied. To our knowledge this is the first detection and isolation of N,N′-diaryldiazapentadiene derivatives as intermediates in the Combes F-alkyl substituted quinoline synthesis starting from enaminoketones. Finally, we succeeded isolating and identifying unsymmetrically substituted 2-perfluorolakyldiazapentadiene. 相似文献
6.
Ali Maghzi Ali Mohebbi Riyaz Kharrat Mohammad Hossein Ghazanfari 《Transport in Porous Media》2011,87(3):653-664
It is well known that the oil recovery is affected by wettability of porous medium; however, the role of nanoparticles on
wettability alteration of medium surfaces has remained a topic of debate in the literature. Furthermore, there is a little
information of the way dispersed silica nanoparticles affect the oil recovery efficiency during polymer flooding, especially,
when heavy oil is used. In this study, a series of injection experiments were performed in a five-spot glass micromodel after
saturation with the heavy oil. Polyacrylamide solution and dispersed silica nanoparticles in polyacrylamide (DSNP) solution
were used as injected fluids. The oil recovery as well as fluid distribution in the pores and throats was measured with analysis
of continuously provided pictures during the experiments. Sessile drop method was used for measuring the contact angles of
the glass surface at different states of wettability after coating by heavy oil, distilled water, dispersed silica nanoparticles
in water (DSNW), polyacrylamide solution, and DSNP solution. The results showed that the silica nanoparticles caused enhanced
oil recovery during polymer flooding by a factor of 10%. The distribution of DSNP solution during flooding tests in pores
and throats showed strong water-wetting of the medium after flooding with this solution. The results of sessile drop experiments
showed that coating with heavy oil, could make an oil-wet surface. Coating with distilled water and polymer solution could
partially alter the wettability of surface to water-wet and coating with DSNW and DSNP could make a strongly water-wet surface. 相似文献
7.
We develop models for the propagation of intense pulses in solid state media which can have either saturated absorption or reverse absorption. We model subluminal propagation in ruby and superluminal propagation in alexandrite as three and four level systems, respectively, coupled to Maxwell's equations. We present results well beyond the traditional pump-probe approach and explain the experiments of Bigelow et al. [Phys. Rev. Lett. 90, 113903 (2003)]Science 301, 200 (2003)]] on solid state materials. 相似文献
8.
Kinsuk Das Tarak Nath Mandal Somnath Roy Samik Gupta Anil Kumar Barik Partha Mitra Arnold L. Rheingold Susanta Kumar Kar 《Polyhedron》2010
The varying coordination modes of the title ligand, L [5-methyl-1-(pyridin-2-yl)-N′-[pyridin-2-ylmethylidene]pyrazole-3-carbohydrazide] towards the different metal centers is reported by preparation and characterization of Cu(II), Zn(II) and Cd(II) complexes, [Cu(L)NO3.H2O](NO3) (1) [Zn(L)2](ClO4)2·2DMF (2) and [Cd(L)(I)2] (3) respectively. In 1, the neutral ligand serves as tetradentate 4 N donor where both pyridine and pyrazole nitrogen atoms of pyridyl–pyrazole part are coordinatively active, leaving the carbonyl oxygen of the carbohydrazide part inactive. The same pyridine and pyrazole N atoms remain abstained from the coordination process towards the Zn(II) and Cd(II) metal centers. For 2 and 3 the ligand behaves as a tridentate NNO donor where the two nitrogen atoms come from azomethine, pyridine of pyridine-2-carbaldehyde parts and O from carbonyl oxygen atoms (carbohydrazide part). The complex 1 and 2 are distorted octahedral while complex 3 adopts distorted square pyramidal geometry. All the complexes are X-ray crystallographically characterized. 相似文献
9.
Performance of a polymer flood process requires the knowledge of rheological behavior of the polymer solution and reservoir
properties such as rock wettability. To provide a better understanding of effects of polymer chemistry and wettability on
the performance of a polymer flood process, a comprehensive experimental study was conducted using a two-dimensional glass
micromodel. A series of water and polymer flood processes were carried out at different polymer molecular weights, degrees
of polymer hydrolysis, and polymer concentrations in both water-wet and oil-wet systems. Image processing technique was applied
to analyze and compare microscopic and macroscopic displacement behaviors of polymer solution in each experiment. From micro-scale
observations, the configuration of connate water film, polymer solution trapping, flow of continuous and discontinuous strings
of polymer solution, piston-type displacement of oil, snap-off of polymer solution, distorted flow of polymer solution, emulsion
formation, and microscopic pore-to-pore sweep of oil phase were observed and analyzed in the strongly oil-wet and water-wet
media. Rheological experiments showed that a higher polymer molecular weight, degree of hydrolysis, and concentration result
in a higher apparent viscosity for polymer solution and lower oil–polymer viscosity ratio. It is also shown that these parameters
have different impacts on the oil recovery in different wettabilities. Moreover, a water-wet medium generally had higher recovery
in contrast with an oil-wet medium. This experimental study illustrates the successful application of glass micromodel techniques
for studying enhanced oil recovery (EOR) processes in five-spot pattern and provides a useful reference for understanding
the displacement behaviors in a typical polymer flood process. 相似文献
10.
Pritam Dolui Vikas Tiwari Parul Saini Dr. Tarak Karmakar Koushik Makhal Harshita Goel Dr. Anil J. Elias 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(43):e202200829
An efficient, metal-free, catalyst-free and solvent-free methodology for the reductive amination of levulinic acid with different anilines has been developed using HBpin as the reducing reagent. This protocol offers an excellent method to avoid solvents and added catalysts on the synthesis of different kinds of N-substituted pyrrolidones under metal free conditions. It is also the first report for the synthesis of different pyrrolidones by solvent-free as well as catalyst-free methods. The proposed mechanism for the formation of pyrrolidone has been supported by DFT calculations and control experiments. 相似文献