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101.
Using the variational method we calculate mesonic wave function. We report masses and decay constants for heavy-light mesons. Leptonic decay widths of charmed and beauty mesons are also calculated. The obtained results are compared with the available experimental and theoretical data. 相似文献
102.
Three polyamine ligands of N1-(2-nitrobenzyl)-N1-(2-aminoethyl)ethane-1,2-diamine (L1), N1-(2-nitrobenzyl)-N1-(2-aminoethyl)propane-1,3-diamine (L2) and N1-(2-nitrobenzyl)-N1-(3-aminopropyl)propane-1,3-diamine (L3) were synthesized and their cyclocondensation with 2-[2-(2-formyl phenoxy)ethoxy]benzaldehyde (L4) in the presence of various metal(II) ions was examined. These reactions only in the presence of a stoichiometric amount of cadmium(II) nitrate gave the related cadmium(II) macrocyclic Schiff-base complexes. In all the other cases no cyclic complexes have been obtained and metal(II) polyamines were the only products. The complexes have been studied with IR, 1H NMR, 13C NMR, DEPT, COSY, HMQC and microanalysis. The crystal structures of [Cd(NO3)(L5)(μ-NO3)Cd(NO3)(L5)]0.5Cd(NO3)4 (1) and [CdL5(NO3)(CH3OH)]ClO4 (2) have been also determined. 相似文献
103.
Hassan Keypour Reza Azadbakht Sadegh Salehzadeh Hamid Khanmohammadi Hamidreza Khavasi Harry Adams 《Polyhedron》2008
Two new asymmetric tripodal tetraamine ligands, 2-((bis(2-aminoethyl)amino)methyl)benzenamine (L2) and 2-(((2-aminoethyl)(3-aminopropyl)amino)methyl)benzenamine (L3) were synthesized and characterized. [1+1] Macrocyclic Schiff-base complexes containing 1,2-diphenoxyethane head units and a 2-aminobenzyl pendant arm, were synthesized as [MnL4(MeOH)](ClO4)2 (1), [MnL5(MeOH)](ClO4)2 (2), [CdL4(H2O)](NO3)2 (3) and [CdL5(H2O)](NO3)2 (4) from the metal ion templated cyclocondensation reactions of 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde with the (L2) or (L3) tripodal tetraamine ligands. The crystal structure determination of (1) and (4) showed that the complex cations that had formed consisted of pentagonal bipyramidally coordinated Mn(II) and Cd(II) ions, centrally located in a N3O2 macrocycle, with one 2-aminobenzyl pendant arm. Supporting ab initio HF-MO calculations have been undertaken using the standard 3-21G∗ and 6-31G∗ basis sets. 相似文献
104.
This paper describes a new method to prepare graft copolymers, such as polyethylene‐g‐polystyrene (PE‐g‐PS), with a relatively well‐controlled reaction mechanism. The chemistry involves a transformation process from the metallocene copolymerization of ethylene and m,p‐methylstyrene (m,p‐MS) to nitroxide‐mediated “living” free radical polymerization (LRFP) of styrene. The metallocene catalysis produces ethylene‐co‐m,p‐methylstyrene (EMS) random copolymers. Next, 1‐hydroxyl‐2,2,6,6‐tetramethylpiperidine (HO‐TEMPO) was synthesized by the reduction of TEMPO with sodium ascorbate. The macroinitiator (EMS‐TEMPO) was synthesized with the bromination reaction of EMS, and the following nucleofilic reaction with this functional nitroxyl compound. The resulting macroinitiator (EMS‐TEMPO) for LRFP was then heated in the presence of styrene to form graft copolymer. DSC, 1H‐NMR, FTIR spectroscopy were employed to investigate the structure of the polymers. The results of Molau test showed that PE‐g‐PS could be a potential good compatilizer. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
105.
This study describes the synthesis, characterization, and in vitro evaluation of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-gadolinium (Gd)-doxorubicin (Dox) conjugates. Copolymers of HPMA were derivatized to incorporate side chains for Gd chelation and Dox conjugation. The conjugates were characterized by their side chain contents, T(1) relaxivity (r(1)), stability, and in vitro cytotoxicity. High stability and relaxivity of these conjugates coupled with low toxicity show their potential for monitoring the in vivo fate of HPMA-based drug delivery systems by magnetic resonance imaging techniques. 相似文献
106.
Elham Tabrizian Ali Amoozadeh Salman Rahmani Mehdi Salehi Maciej Kubicki 《Research on Chemical Intermediates》2016,42(2):531-544
A new and economical synthesis of α, α′-bis(substituted-benzylidene)cycloalkanones has been achieved by the reaction of cycloalkanones with different aromatic aldehydes using nano-TiO2/acetic acid as a catalyst in ethanol under reflux conditions with excellent yields. Five new products and three new single crystal structures are reported. 相似文献
107.
108.
Hamidreza Ardalani Syariful Anam Kresten J. K. Kromphardt Dan Staerk Kenneth T. Kongstad 《Molecules (Basel, Switzerland)》2021,26(6)
With the identification of novel antibiotics from nature being pivotal in the fight against human pathogenic bacteria, there is an urgent need for effective methodologies for expedited screening of crude extracts. Here we report the development and validation of a simple and dye-free antimicrobial assay in 96-well microplate format, for both determination of IC50 values and high-resolution inhibition profiling to allow pin-pointing of bioactive constituents directly from crude extracts. While commonly used antimicrobial assays visualize cell viability using dyes, the developed and validated assay conveniently uses OD600 measurements directly on the fermentation broth. The assay was validated with an investigation of the inhibitory activity of DMSO against Staphylococcus aureus, temperature robustness, interference by coloured crude extracts as well as inter-day reproducibility. The potential for high-resolution S. aureus growth inhibition profiling was evaluated on a crude extract of an inactive Alternaria sp., spiked with ciprofloxacin. 相似文献
109.
Shahnaz Sargazi Ramazan Mirzaei Mashaallah Rahmani Mahdi Mohammadi Abdolali Khammari Masoome Sheikh 《Journal of Analytical Chemistry》2017,72(5):557-561
Di(2-ethylhexyl) phthalate (DEHP) is used as plasticizer in polyvinylchloride (PVC) plastics. Its metabolites and the parent phthalates are considered toxic. As the DEHP plasticizers are not chemically bound to PVC, they can migrate, evaporate or be leached into indoor air and atmosphere, foodstuff, and other materials. We have reported a novel, easy and available analytical method for the determination of DEHP and its metabolite, mono(2-ethylhexyl) phthalate (MEHP) in human urine samples by the in-syringe dispersive liquid–liquid microextraction method coupled with gas chromatography with flame ionization detector. The limits of detection and precision (RSD) were 2.5 μg/L and 1.4% for DEHP and 1.1 μg/L and 3.0% for MEHP, respectively. This method could be utilized for routine monitoring of the trace DEHP and MEHP in urine of human exposure to plasticizers. 相似文献
110.
Exceedingly Facile PhX Activation (X=Cl,Br, I) with Ruthenium(II): Arresting Kinetics,Autocatalysis, and Mechanisms 下载免费PDF全文
Dr. Fedor M. Miloserdov Dr. David McKay Dr. Bianca K. Muñoz Dr. Hamidreza Samouei Prof. Stuart A. Macgregor Prof. Vladimir V. Grushin 《Angewandte Chemie (International ed. in English)》2015,54(29):8466-8470
[(Ph3P)3Ru(L)(H)2] (where L=H2 ( 1 ) in the presence of styrene, Ph3P ( 3 ), and N2 ( 4 )) cleave the Ph? X bond (X=Cl, Br, I) at RT to give [(Ph3P)3RuH(X)] ( 2 ) and PhH. A combined experimental and DFT study points to [(Ph3P)3Ru(H)2] as the reactive species generated upon spontaneous loss of L from 3 and 4 . The reaction of 3 with excess PhI displays striking kinetics which initially appears zeroth order in Ru. However mechanistic studies reveal that this is due to autocatalysis comprising two factors: 1) complex 2 , originating from the initial PhI activation with 3 , is roughly as reactive toward PhI as 3 itself; and 2) the Ph? I bond cleavage with the just‐produced 2 gives rise to [(Ph3P)2RuI2], which quickly comproportionates with the still‐present 3 to recover 2 . Both the initial and onward activation reactions involve PPh3 dissociation, PhI coordination to Ru through I, rearrangement to a η2‐PhI intermediate, and Ph? I oxidative addition. 相似文献