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11.
Me2Sn(O2PPh2)2 ( 1 ), Ph2Pb(O2PMe2)2 ( 2 ), and Ph2Pb(O2PPh2)2 ( 3 ) have been synthesized by the reactions of Me2SnCl2 or Ph3PbCl with the corresponding diorganophosphinic acid in methanol. X‐ray diffraction studies show that the diorganophosphinate groups behave as double bridges between the metal atoms leading to polymeric ring‐chain structures with M2O4P2 (M = Pb, Sn) eight‐membered rings. The organic groups bonded to the metal atoms are in trans‐position in the resulting octahedral arrangement around the metal atoms. The IR and the mass spectra were reported and discussed. 相似文献
12.
The dosimetric characteristics of γ-radiation-induced defects in magnesium lactate (ML) rods (3.5 mm×10 mm) formulated by mixing ML with molten mixtures of paraffin wax and EVA copolymer have been investigated using electron paramagnetic resonance (EPR). The EPR spectrum of irradiated ML rods was characterized by a quartet signal with the spectroscopic splitting g-factor of 2.0048±0.0003 at 0.4 mT. The useful dose range of the rod dosimeter was 100 Gy to 80 kGy. The mass attenuation coefficient, μ/ρ, and the mass energy-absorption coefficient, μen/ρ, versus energy in the range of 10 keV to 20 MeV indicate that the prepared ML dosimeter is typically adipose tissue equivalent overall this energy range. The overall combined uncertainties (at 2σ) associated with routine dose monitoring in the dose range of 0.1–10 kGy and 10–80 kGy were found to be 6.14% and 6.36%, respectively. 相似文献
13.
Qinjun Kang Peter C. Lichtner Hari S. Viswanathan Amr I. Abdel-Fattah 《Transport in Porous Media》2010,82(1):197-213
We apply a multi-component reactive transport lattice Boltzmann model developed in previous studies for modeling the injection
of a CO2-saturated brine into various porous media structures at temperatures T = 25 and 80°C. In the various cases considered the porous medium consists initially of calcite with varying grain size and
shape. A chemical system consisting of Na+, Ca2+, Mg2+, H+, CO2°(aq){{\rm CO}_2^{\circ}{\rm (aq)}}, and Cl− is considered. Flow and transport by advection and diffusion of aqueous species, combined with homogeneous reactions occurring
in the bulk fluid, as well as the dissolution of calcite and precipitation of dolomite are simulated at the pore scale. The
effects of the structure of the porous media on reactive transport are investigated. The results are compared with a continuum-scale
model and the discrepancies between the pore- and continuum-scale models are discussed. This study sheds some light on the
fundamental physics occurring at the pore scale for reactive transport involved in geologic CO2 sequestration. 相似文献
14.
15.
M. I. Ali A. M. Abdel-Fattah S. M. Hussain A. M. El-Reedy 《Journal of heterocyclic chemistry》1982,19(5):993-996
2-Carboxy-1-alkylindole-3-acetic acid anhydrides (I) condensed with S-methylisothiosemicarbazide in DMF to form 5,11-dihydro-6-methyl-2-methylthioindolo[3′,2′:4,5]pyrido[1,2-b]-s-triazol-5-one (II). Compound II underwent ring opening on refluxing with sodium hydroxide solution to give IV. The anhydride I reacted with primary amines in benzene to give 2-carboxy-1-alkylindole-3-acetanilide derivatives (VI) which yielded l-methylindole-3-acetic acid by decarboxylation followed by hydrolysis. Compound II oxidised to the diketo compound X which could be prepared by the hydrolysis of the azomethine derivative IX with acetic acid-hydrochloric acid mixture. Compound II reacted with benzyl chloride to yield the dibenzyl derivative XII, condensed with p-chlorobenzaldehyde to form the 11-p-chlorobenzylidene derivative XI and coupled with arenediazonium salt to give the 11-arylhydrazone derivatives XIII. 相似文献
16.
Katritzky AR Abdel-Fattah AA Gromova AV Witek R Steel PJ 《The Journal of organic chemistry》2005,70(23):9211-9214
[Reaction: see text]. Readily available N-acylbenzotriazoles 2a-l (derived from a variety of aliphatic, (hetero)aromatic, and N-protected alpha-amino carboxylic acids) smoothly convert primary 3a-c and alpha-functionalized primary nitroalkanes 3d into the corresponding alpha-nitro ketones 5a-p in yields of 39-86% (average 63%). 相似文献
17.
Abdel-Fattah Shihada Ihsan Abdel-Amir Jassim Frank Weller 《Journal of organometallic chemistry》1984,268(2):125-133
A series of trimethyltin diorganothiophosphinates Me3SnOSPR′R″ (R′R″ = Me2, MePh, Ph2) was prepared from (Me3Sn)2O and R′R″PSCl in cyclohexane solution. A close study of the vibrational spectra is given; 31P NMR and mass spectra are also reported. The structural investigation of Me3SnOSPMe2 by means of X-ray diffraction (R 5.2%, 1697 observed independent reflexions) shows the compound to consists of chains, in which planar SnMe3 units and tetrahedral OSPMe2 groups are linked by the O- and S-atoms of the thiophosphinate. 相似文献
18.
2,5-Dioxypiperazine (DOPZ) was covalenty bonded as a chelating compound to chloropropyltrimethoxysilane (Si–Cl) for the formation of a new chemisorbed silica [Si–(CH2)3–DOPZ]. Physisorbed silica-loaded-2,5-dioxypiperazine [Si–DOPZ] was also synthesized via a physical adsorption approach. Elucidation of the chemisorption and physisorption of 2,5-dioxypiperazine onto silica was confirmed on the basis of 70 eV electron impact mass spectrometric (70 eV EI-MS) mode of ionization via a direct insertion probe (DIP) as a promising technique for providing characteristic fragment ion peaks. The metal probe testing method and elemental analysis were applied to determine the surface coverage values and these were found to be 0.179 and 0.160 mmol g−1 for [Si–(CH2)3–DOPZ] and 0.251 mmol g−1 for [Si–DOPZ]. [Si–(CH2)3–DOPZ] was characterized by high stability in acidic and buffer solutions, pH 1–7, compared to [Si–DOPZ]. Differential scanning calorimetry studies (DSC) for the modified silica were performed to evaluate the various thermodynamic and kinetic parameters of the thermal degradation processes, and these have been enumerated. The results obtained by both EI-MS and DSC are very similar in many respects. Metal chelation and stoichiometric properties of chemically modified silica were evaluated on the basis of the metal binding capacity, distribution coefficient and separation factor for a series of metal ions. The evaluated results refer to the high metal chelating properties of [Si–(CH2)3–DOPZ] for cadmium(II), lead(II) copper(II) and mercury(II). These four [Si–(CH2)3–DOPZ]–metal complexes were also synthesized and the identified stoichiometric ratios were found to be 1:2 based on the nitrogen and metal analysis. EI-MS via 70-eV ionization was also used as a potential method for further confirmation of the metal complex formation based on structure and fragmentation elucidation. DSC studies of these four metal complexes were also performed and evaluated. 相似文献
19.
Primary and secondary cyanides are efficiently acylated with N-acylbenzotriazoles 3a-f (derived from a variety of acids) to afford the corresponding alpha-substituted beta-ketonitriles 5a-r in 67-96% yields. 相似文献
20.
Acyclic sulfones 4a-f and alicyclic sulfone 7 react with readily available N-acylbenzotriazoles 3a-g (derived from aliphatic, aromatic, and heteroaromatic carboxylic acids) to provide the corresponding beta-keto sulfones 5a-n and 8a-c, respectively, in good to excellent yields. 相似文献