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141.
Mohamad Jaber Al-Jeboori Ahlam Jamil Abdul-Ghani Ahmed Jasim Al-Karawi 《Transition Metal Chemistry》2008,33(7):925-930
The new Mannich bases bis(1,4-diphenylthiosemicarbazide methyl) phosphinic acid H3L1 and bis(1,4-diphenylsemicarbazide methyl) phosphinic acid H3L2 were synthesised from the condensation of phosphinic acid, formaldehyde with 1,4-diphenyl thiosemicarbazide and 1,4-diphenylsemicarbazide,
respectively. Monomeric complexes of these ligands, of general formulae K2[CrIII(L
n
)Cl2], K3[MnII(L
n
)Cl2] and K[M(L
n
)] (M = Co(II), Ni(II), Cu(II), Zn(II) or Hg(II); n = 1, 2), are reported. The mode of bonding and overall geometry of the complexes were determined through physico-chemical
and spectroscopic methods. These studies revealed octahedral geometries for the Cr(III), Mn(II) complexes, square planar for
Co(II), Ni(II) and Cu(II) complexes and tetrahedral for the Zn(II) and Hg(II) complexes. 相似文献
142.
143.
Herbert Schumann Jens Kaufmann Birgit C. Wassermann Frank Girgsdies Nimer Jaber Jochanan Blum 《无机化学与普通化学杂志》2002,628(5):971-978
The enantiomerically pure dimeric N, O‐5‐chelates [Me2In(μ‐OCH2CH(R)NMe2)]2 {R = Me (S) ( 2 ); R = iPr (S) ( 3 ); R = iBu (S) ( 4 ); R = Bz (S) ( 5 )}, and [Me2In‐{μ‐(1R, 2S)‐OCH(Ph)CH(Me)NMe2}]2 ( 6 ), as well as the achiral dimeric N, O‐6‐chelate [Me2In(μ‐O(CH2)3NMe2)]2 ( 7 ) have been synthesized from trimethylindium and equimolar amounts of the corresponding enantiomerically pure dimethylamino alcohols or of the achiral dimethylaminopropanol by elimination of methane. Their 1H NMR, 13C NMR, and mass spectra as well as the X‐ray single crystal structure analyses of [Me2In{μ‐O(CH2)2NMe2}]2 ( 1 ), 3, 5, 6 and 7 are described and discussed. The coordinative N→In bonds of the five‐coordinate indium complexes show dynamic dissociation/association processes. 1—6 were found to be useful reagents for the partial kinetic resolution of 2‐carbomethoxy‐1, 1′‐binaphthyl triflate. 相似文献
144.
Micromachined shallow arch resonant beams have attracted significant attention thanks to their rich dynamical behavior, inherent nonlinearities, and the potential to excite various internal resonances. Currently, there is a lack of comprehensive experimental studies for the various types of internal resonances in arches and particularly at the micro and nano scales. Here, we aim to investigate and identify different types of internal resonances of an initially curved beam, electrothermally actuated and electrostatically driven, by electrical characterization techniques. Upon changing the electrothermal voltage of silicon micromachined arches, the second symmetric natural frequency of an arch is adjusted to near twice, three times, and four times the fundamental natural frequency, which gives rise to 2:1, 3:1, and 4:1 autoparametric resonances between the two modes. These resonances are demonstrated experimentally. We show various frequency-response curves of the total response around the excitation frequency and highlight the contribution of each mode before, during, and after the internal resonances. Allan-deviation results are also shown indicating enhanced frequency stabilization of the arch oscillation when experiencing internal resonances. These studies motivate further research in this direction to exploit internal resonances of micromachined resonators for practical applications, such as sensors and mechanical amplifier. 相似文献
145.
Waste to wealth: conversion of nano‐magnetic eggshell (Fe3O4@Eggshell) to Fe3O4@Ca(HSO4)2: cheap,green and environment‐friendly solid acid catalyst
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Eggshell is a hazardous waste by European Union regulations, so that discarded thousands of tons per year. To convert waste (eggshell) to wealth (catalyst), nano‐magnetic eggshell was prepared based on the nano‐Fe3O4, and then the eggshell was converted to Ca(HSO4)2 with organic acid, namely, chlorosulfonic acid. Based on the back titration, 5.18 mmol SO4H group was loaded per gram of the nano‐structure. Using this method eggshell was converted to cheap, green and environment‐friendly solid acid catalyst. The prepared catalyst (nano‐ Fe3O4@Ca(HSO4)2) was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), energy dispersive X‐ray spectroscopy (EDX), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and thermal gravimetric analysis (TGA). The activity of eggshell waste‐derived catalysts was successfully evaluated in the synthesis of value‐added products, namely indazolo[1,2‐b]‐phthalazinetrione derivatives as a benchmark multicomponent reaction. In addition, design of experiments shows that increase in amount of catalyst (and temperature), boost the reaction yield, especially with steeper slope at higher temperature. 相似文献
146.
Sadeghiseraji Jaber Moradicheghamahi Jafar Sedaghatkish Amir 《Journal of Thermal Analysis and Calorimetry》2021,143(6):4039-4056
Journal of Thermal Analysis and Calorimetry - The main objective of this study is to capture the function of temperature separation inside a vortex tube (VT), firstly, via testing it at different... 相似文献
147.
Estephan ZG Jaber JA Schlenoff JB 《Langmuir : the ACS journal of surfaces and colloids》2010,26(22):16884-16889
Using a short-chain zwitterionic organosiloxane, silica nanoparticles were stabilized against aggregation by high ionic strength and/or proteins. Turbidimetry and dynamic light scattering showed that "zwitterated" nanoparticles did not exhibit a significant increase in hydrodynamic radius. When challenged with 3 M NaCl or 50% fetal bovine serum, aggregation was inhibited for at least 24 h, longer with mild heat treatment, which produced nanoparticles with zero net surface charge. These findings suggest "zwitteration" of silica-capped nanoparticles provides excellent stability for in vivo circulation diagnostics and therapies. 相似文献
148.
Mohamad Jaber Al-Jeboori Amar H. Al-Dujaili Alyaa E. Al-Janabi 《Transition Metal Chemistry》2009,34(1):109-113
The Schiff base N-crotonyl-2-hydroxyphenylazomethine HL, derived from the reaction of acrylamide and salicylaldehyde, was synthesised. Polymeric
complexes were obtained from the reaction of polymeric HL with divalent metals. The mode of bonding and overall geometry of
the complexes were determined through physico-chemical and spectroscopic methods and compared with that previously reported
for the analogous monomeric ligand. These studies revealed tetrahedral geometries around the metal centres for Mn(II), Co(II),
Zn(II), Cd(II) and Hg(II) complexes of general formula [M(L)Cl], octahedral for Ni(II) and Cu(II) complexes of general formula
[M′(L)Cl(H2O)2], and square planar for Pd(II) complex of general formula [Pd(L)Cl]. 相似文献
149.
In this paper we prove that the Fremlin tensor product of two f-algebras can be endowed with an f-algebra structure and satisfies an appropriate universal property. In particular, the Riesz tensor product of C(X) and C(Y), where X and Y are topological spaces, is an f-subalgebra of C(X × Y). 相似文献
150.
Malek Taher Maghsoodlou Reza Heydari Nourallah Hazeri Sayyed Mostafa Habibi‐Khorassani Mahmoud Nassiri Marjan Ghasemzadeh Jaber Salehzadeh Zahra Gharechaei 《Heteroatom Chemistry》2009,20(4):240-245
Aromatic amine phosphonato esters 4a–d were obtained in excellent yields from the 1:1:1 addition reaction between triphenyl phosphite and dimethyl acetylenedicarboxylate in the presence of NH‐aromatic amines such as 2‐aminobenzophenone, 2‐aminoacetophenon, methyl‐2‐aminobenzoate, and 2‐aminobenzonitrile. In the recent works, the assignments of the configuration of 4a–d corresponding to the three‐bond carbon‐phosphorus coupling, 3Jpc, was determined on the basis of coupling constants by the Karplus equation as 2R *, 3R *or 2S *, 3S * while they were 2R *, 3S * or 2S *, 3R * in our previous works in the presence of same solvent. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:240–245, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20541 相似文献