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371.
372.
S. Rehman M. Arshad K. Masud R. Afzal U. Salma 《Journal of Thermal Analysis and Calorimetry》2010,102(2):715-722
A series of octahedral complexes, [M(EDDA)(H2O)2] · H2O (where, M+2 = Co(II), Cu(II), Ni(II) and Zn(II); EDDA, ethylenediamine-N,N′-diacetate), was prepared and studied by means of thermogravimetry (TG) and differential thermal analysis (DTA). Their compositions
were investigated by elemental analysis in order to ensure their purity and structural elucidation was based on spectral and
magnetic properties. Thermal decomposition of these distorted octahedral complexes, [Ni(EDDA)(H2O)2], [Co(EDDA)(H2O)2] · H2O, [Cu(EDDA)(H2O)2] · H2O and [Zn(EDDA)(H2O)2] · H2O came of in one, two, three and four steps, respectively, upon heating to 800 °C, with the loss of organic and inorganic
fragments. Ligand decomposed in three steps. The thermal degradation of all the complexes in static air atmosphere started
at temperatures lower than those observed for the free ligand degradation (Ni-complex being the only exception). The composition
of intermediates formed during degradation was confirmed by microanalysis and IR spectroscopy. The residues corresponded to
metal oxide except for Ni(II) and Zn(II) complexes. It was found that thermal stability of the complexes increased in the
following sequence:
\textCu(II) ~ \textCo(II) < \textZn(II) < \textNi(II) {\text{Cu(II)}} \sim {\text{Co(II)}} < {\text{Zn(II)}} < {\text{Ni(II)}} 相似文献
373.
The efficiency and selectivity of Cu‐catalyzed allylic acetoxylation of alkene in different solvent systems is improved by the presence of different metallic salts in the reaction medium. The methodology is particularly well employed for the direct allylic acetoxylation of Δ5‐steroids at 7‐position, for which the resulting acetoxylated product obtained was exclusively α‐isomer. Excellent yield was achieved (up to 90%) under optimized conditions, while significantly reducing the costs and environmental hazards and increasing the yield as compared to the other previously reported methods. 相似文献
374.
Tariq Mahmud Rabia Rehman Aqsa Gulzar Amina Khalid Jamil Anwar Umer Shafique Muhammad Salman 《Arabian Journal of Chemistry》2010,3(4):219-224
Complexes of enaminones; 4-N,N-diethylamine-pent-3-ene-2-one [HL1], 4-N,N-di n-propylamine-pent-3-ene-2-one [HL2] and 4-N,N-dicyclohexylamine-pent-3-ene-2-one [HL3] with Fe(II) and Zn(II) ions were prepared by reacting the equimolar ethanolic solutions of the ligands (HL1, HL2 and HL3) with ethanolic metal solutions. The complexes formed, were characterized by infrared, ultraviolet and atomic absorption spectroscopy. Ligands and their metal complexes were tested against Escherichia coli and Staphylococcus aureus bacteria to assess their antibacterial action using disc diffusion method. Ligands were completely inactive against bacteria whereas the complex Zn (HL1) has significant action on both bacteria, indicating that it has a good potential as bactericide. Other complexes have normal antiseptic character. 相似文献
375.
Hussain J Bukhari N Hussain H Rehman NU Hussain SM 《Natural product communications》2010,5(11):1785-1786
Phytochemical investigation of Nepeta distans Raul resulted in the isolation of a new phenolic compound, nepatanol (1), and eight known compounds, markhamioside F, netidiol, nepedinol, thymoquinone, eugenol, oleanolic acid, ursolic acid, and beta-sitosterol, which have been isolated for the first time from this source. Structures of all the isolates were established on the basis of MS, and 1D and 2D NMR spectral data and by comparison with reported data. 相似文献
376.
377.
Some biologically important tin(Ⅳ) complexes derived from 5,5-diethyl sodium barbital have been synthesized and characterized through various analytical and spectroscopic techniques such as IR, ^1H-, ^13C-NMR and ^119mSn mossbauer. On the basis of these spectroscopic techniques, octahedral geometry has been assigned to all the novel compounds. These complexes, soluble in DMSO and DMF, were screened against a wide range of microorganisms. The results proved that the diphenyltin(Ⅳ) and dibutyltin(Ⅳ) complexes exhibit excellent activity against all types of microorganisms, while the rest of the compounds show significant activity that can be used during the biological study. 相似文献
378.
Peter A. Lieberzeit Abdul Rehman Naseer Iqbal Bita Najafi Franz L. Dickert 《Monatshefte für Chemie / Chemical Monthly》2009,391(8):947-952
Abstract An e-nose comprised of six sensing channels each coated with a molecularly imprinted polymer (MIP) selectively interacting
with alpha-pinene, thymol, estragol, linalool, and camphor, respectively, was designed. When applying it for continuous online
surveillance of terpenes emitted from basil and peppermint leaves as a criterion of freshness, it very appreciably reproduced
the emanation patterns from these plants as shown by GC-MS. Chromatography yielded a variety of terpenes in a concentration
range below 70 ppm. Trend lines obtained from the e-nose were corroborated by GC-MS and also appreciably fit the usual conduct
of these plants as observable by the human nose.
Graphical abstract
相似文献
379.
Bidhan Pandit Emad S.Goda Mahmoud H.Abu Elella Aafaq ur Rehman Sang Eun Hong Sachin R.Rondiya Pranay Barkataki Shoyebmohamad F.Shaikh Abdullah M.Al-Enizi Salah MEl-Bahy Kuk Ro Yoon 《Journal of Energy Chemistry》2022,(2):116-126
An eco-friendly,new,and controllable approach for the preparation of manganese oxide(a-MnO2)nanorods has been introduced using hydrothermal reaction for supercapacitor application.The in-depth crystal structure analysis ofα-MnO2 is analyzed by X-ray Rietveld refinement by using Full Prof program with the help of pseudo-Voigt profile function.The developed a-MnO2 electrode attains a remarkable capacitance of 577.7 F/g recorded at a current density value of 1 A/g with an excellent cycle life when is used for 10,000 repeated cycles due to the porous nanorod-morphology assisting the ease penetration of electrolyte ions into the electroactive sites.The diffusive and capacitive contributions of the electrode have been estimated by considering standard numerical packages in Python.After successfully assembling the aqueous symmetric supercapacitor(SSC)cell by utilizing the as-preparedα-MnO2,an excellent capacitance of 163.5 F/g and energy density of 58.1 Wh/kg at the constant current density of 0.5 A/g are obtained with an expanded potential frame of 1.6 V.Moreover,the cell has exceptionally withstood up to 10,000 cycles with an ultimate capacitance retention of 94.1%including the ability to light an LED for 18 s.Such findings recommend the developed a-MnO2 electrode to be a highly felicitous electrode for the field of energy storage. 相似文献
380.
Hongying Mao Weidong Dou Ateeq ur Rehman Qing Liao Haiyang Li Shining Bao 《Applied Surface Science》2010,256(11):3598-3602
Using a combination of scanning tunneling microscopy (STM) and density functional theory calculations, we have studied the adsorption of tetracene on the Cu(1 1 0) (2 × 1)O substrate. At monolayer coverage the adsorbed molecules are in the flat-laying geometry with their long axis along the close-packed [0 0 1] direction of the substrate and a long-range ordered structure on the length scale up to 100 nm has been observed. DFT calculation results indicate a stronger interaction between tetracene molecules and Cu(1 1 0) substrate than Cu(1 1 0) (2 × 1)O substrate. The preferential adsorption sites have also been pointed out on both substrates. The observed wavelike structure is explained by the interdigitation of C-H bonds of adjacent molecules. 相似文献
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