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A few kinds of novel Schiff base complexes have been prepared by three component reaction of the substituted hydroxyacetophenone with several aliphatic diamines and transition metals such as; Ni(II), Zn(II) and UO2(II) under mild reaction conditions. The products have been afforded with excellent yields and appropriate reaction times. The structure of these ligands has been characterized by their IR, 1H NMR, 13C NMR and MS spectral and physical data. 相似文献
96.
Hamed Douroudgari Hamed Bahrami Farshad Mirzaee Valadi Manijeh Tozihi Nasim Najafloo Morteza Vahedpour 《Journal of mass spectrometry : JMS》2022,57(3):e4814
The current research is constructed for considering the chemical ionization and dissociation of perindopril in the positive mode of corona discharge ion mobility spectrometry. Four product ion peaks are observed in the ion mobility spectrum of perindopril erbumine at the cell temperature of 473 K. These peaks are assigned through the obtained intensity variation analysis in the ion mobility spectra over the elapsed time accompanied by the calculations backed by the validated density functional theory (DFT). In this regard, the most stable ionic species associated with each peak and the corresponding reliable generation pathways are found by the well-confirmed meta hybrid density functional method, M06-2X. The peaks are assigned to the protonated perindopril and its dissociation products, including counter ion and the related fragment ions. However, the structures of the neutral perindopril in the gas phase are thoroughly assessed to find a more stable one. The predicted chemical ionization products by the theory are in excellent agreement with our presented experiment here. Theoretical evaluations demonstrated that the production of a fragment by dissociation process occurs when perindopril gets a proton from the ionization region. Also, without protons, there is no dissociation process. Therefore, our mechanism investigated here is the proton transfer one. All possible sites of perindopril are considered theoretically for protonation along with their possible reactions. In addition to the computed PES, the assigned ions for obtained spectra are confirmed by the computed equilibrium constants and rate constants. Our theoretical results show that the peak of the main fragment is for M-CH3CH2OH produced by a reaction pathway involving no barrier. This study opens new perspectives in interpreting large molecules spectra for future studies. 相似文献
97.
Electrical properties of SiO2 grown on the Si-face of the epitaxial 4H-SiC substrate by wet thermal oxidation technique have been experimentally investigated
in metal oxide-silicon carbide (MOSiC) structure with varying oxide thicknesses employing Poole-Frenkel (P-F) conduction mechanism.
The quality of SiO2 with increasing thickness in MOSiC structure has been analysed on the basis of variation in multiple oxide traps due to effective
P-F conduction range. Validity of Poole-Frenkel conduction is established quantitatively employing electric field and the
oxide thickness using forward I–V characteristics across MOSiC structures. From P-F conduction plot (ln(J/E) vs. E
1/2), it is revealed that Poole-Frenkel conduction retains its validation after a fixed electric field range. The experimental
methodology adopted is useful for the characterization of oxide films grown on 4H-SiC substrate. 相似文献
98.
Ali Akbar Ashkarran Azam Iraji?zad Seyed Mohammad Mahdavi Mohammad Mahdi Ahadian 《Applied Physics A: Materials Science & Processing》2010,100(4):1097-1102
ZnO nanostructures were synthesized through arc discharge of zinc electrodes in deionized (DI) water. X-ray diffraction (XRD)
analysis of the prepared nanostructures indicates formation of crystalline ZnO of hexagonal lattice structures. Transmission
electron microscopy (TEM) images illustrate rod-like as well as semi spherical ZnO nanoparticles with 15–20 nm diameter range,
which were formed during the discharge process with 5 A arc current. The average particle size was found to increase with
the increasing arc current. X-ray photoelectron spectroscopy (XPS) analysis confirms formation of ZnO at the surface of the
nanoparticles. Surface area of the sample prepared at 5 A arc current, measured by BET analysis, was 34 m2/g. Photodegradation of Rhodamine B (Rh. B) shows that the prepared samples at lower currents have a higher photocatalytic
activity due to larger surface area and smaller particle size. 相似文献
99.
Mahmood Z Azam M Mushtaq A Kausar R Kausar S Gilani SR 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,65(2):445-452
The infrared spectra of pure Mn(CO)(5)X in the region 4000-400 cm(-1) has been obtained in the vapour phase. The observed spectrum has been analyzed to distinguish the fundamental frequencies, the rotational-vibrational and structure, and overtone and combination frequencies. The assignment of the observed vapour phase frequencies to the fundamental modes of vibration has been made on C(4V) symmetry. The weak peaks due to XMn(CO)(4)((13)CO) molecules have been measured and assigned for all molecules. This study provides a comprehensive comparison of these compounds, with all of these data the assignment of frequencies is reviewed and a set of quite unambiguous assignments made. The significant finding in this regards are that, it is not necessary to assume lower than C(4V) symmetry for XMn(CO)(5) as has been done in previous consideration of some infrared spectrum of these compounds. 相似文献
100.
Fariba Bahrami Jonas Nycander Robab Alikhani 《Nonlinear Analysis: Real World Applications》2010,11(3):1589-1599
The existence of an energy maximizer relative to a class of rearrangements of a given function is proved. The maximizers are stationary and stable solutions of the quasigeostrophic equation, which governs the time evolution of large-scale three-dimensional geophysical flow in a vertically bounded domain. The background flow is unidirectional, with linear horizontal shear. The theorem proved implies the existence of a family of stationary and stable vortices that rotate in the same direction as the background shear. It extends an earlier theorem by Burton and Nycander, which is valid for a vertically unbounded domain. 相似文献