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61.
Chandrasekhar V Rahaman SM Hajra T Das D Ghatak T Rafiq S Sen P Bera JK 《Chemical communications (Cambridge, England)》2011,47(38):10836-10838
The trinuclear complex [{Ir(ppy)(2)}(3)(L(1))(2)](OTf)(3) (1) is a bright red luminophore whereas the monomer [Ir(ppy)(2)L(2)](OTf) (2) exhibits emission in the green region. 相似文献
62.
Fazal-ur Rehman Shahid Adeel Summia Qaiser Ijaz Ahmad Bhatti Muhammad Shahid Mohammad Zuber 《Radiation Physics and Chemistry》2012,81(11):1752-1756
Dyeing behavior of gamma irradiated cotton fabric using Lawson dye extracted from henna leaves has been investigated. Cotton and dye powder are irradiated to different absorbed doses of 2, 4, 6, 8 and 10 kGy using Cs-137 gamma irradiator. The dyeing parameters such as dyeing time, electrolyte (salt) concentration and mordant concentrations using copper and iron as mordants are optimized. Dyeing is performed using un-irradiated and irradiated cotton with dye solutions and their color strength values are evaluated in CIE Lab system using Spectraflash –SF650. Methods suggested by International Standard Organization (ISO) have been employed to investigate the colourfastness properties such as colourfastness to light, washing and rubbing of irradiated dyed fabric. It is found that gamma ray treatment of cotton dyed with extracts of henna leaves has significantly improved the color strength as well as enhanced the rating of fastness properties. 相似文献
63.
Muhammad Hanif Muhammad Rafiq Muhammad Saleem Muhammad Mustaqeem Saba Jamil Muhammad Ramzan Saeed Ashraf Janjua 《中国化学会会志》2019,66(5):500-505
The development of a fluorescent sensor for the trace detection of the metallic contamination in the ecosystem and biological media have been a demand to reduce the health risk and environmental protection. Herein, we report the synthesis of 2‐formyl‐5‐picolinyl‐substituted rhodamine B derivative through Schiff base formation for the trace detection of the copper ions in the aqueous organic media as well as inside the live cells via bioimaging experiments. The ligand was successfully employed to detect the minute copper level ratiometrically through the chromogenic and fluorogenic response. The detection limit of the sensor was found to be 0.54 × 10?9 mol/L using 3 σ/slope relations. The reversible behavior of the ligand copper complex was determined using sulfide ions that regenerate the entire native properties of the ligands by snatching copper from the complex. The bioimaging experimental results represent the efficient membrane permeability of ligands with the minimum level of toxicity in the measured range found by the MTT assay. The appearance of bright red fluorescence from the BHK‐21 (hamster kidney fibroblast) cells upon treatment of the ligand incubated cells with the copper ions represents the utility of the proposed sensor for the copper detection probe in the intracellular media. 相似文献
64.
Due to the deleterious effects of mercury on human health and natural ecosystems, high reactivity, non-degradability, extreme volatility and relative water and tissue solubility, it would consider as one of the most toxic environmental pollutants among the transition metals. In the present investigation, we have tried to summarized the several organic material based fluorescent sensor including rhodamine, boron-dipyrromethene (BODIPYs), thiourea, crown-ether, coumarine, squaraines, pyrene, imidazole, triazole, anthracene, dansyl, naphthalenedimide/ naphthalene/ naphthalimide, naphthyridine, iridium (III) complexes, polymeric materials, cyclodextrin, phthalic anhydride, indole, calix [4]arene, chromenone, 1,8-naphthalimides, lysine, styrylindolium, phenothiazine, thiocarbonyl quinacridone, oxadiazole, triphenylamine–triazines, tetraphenylethene, peptidyl and semicarbazone for the trace mercury detection in the aqueous, aqueous–organic and cellular media. The present review provides a brief look over the previous development in the organic material based fluorescent sensor for mercuric ion detection. Furthermore, the ligand-metal binding stoichiometry, binding/association/dissociation constants and the detection limit by the receptors have been particularly highlighted which might be useful for the future design and development of more sensitive and robust fluorescent chemosensor/chemodosimeter for the mercuric ion detection. 相似文献
65.
A vehicle guidance system has been developed using ultrasonic sensing. The ultrasonic technology is presented in this paper with reference to how it links in with the complete system. The ultrasonic unit is based on electrostatic transducer technology and comprises a separate linear array and curved divergent transmitter which gives it an effective field of view of 60° and a range of more than 5 m. The unit has been designed primarily for use on an unmanned vehicle travelling over rough, unknown terrain. 相似文献
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Variations in the ligand structure of homogeneous late transition metal catalysts through judicious choice and location of substituent is the foremost strategy in improving their catalytic performance for ethylene polymerization. In this contribution, symmetrical and unsymmetrical bis(imino)pyridylcobaltous chloride complexes adorned with nitro and benzhydryl groups {2‐[1‐(2,6‐dibenzhydryl‐4‐nitrophenylimino)ethyl]‐6‐[1‐(alkylphenylimino)ethyl]pyridylcobaltous chloride (alkyl: R1 = Me and R2 = H, Co1 ; R1 = Et and R2 = H, Co2 ; R1 = iPr and R2 = H, Co3 ; R1 and R2 = Me, Co4 ; R1 = Et and R2 = Me, Co5 ; R1 = benzhydryl and R2 = NO2, Co6 )} have been prepared and applied as catalysts for ethylene polymerization. The molecular structure of Co1 and Co2 revealed the unequal steric protection of the cobalt center induced by bis(imino)pyridine chelate. In the presence of methylaluminoxane (MAO) or modified methylaluminoxane (MMAO) activators at different ethylene feeding rates (1 and 10 atm), catalysts Co1 – Co5 displayed high activities at 10 atm ethylene and produced strictly linear polyethylene (PE) with high molecular weight, Co2 /MMAO being the most highly active catalytic system showing the highest activity of 9.41 × 106 g of PE (mol of Co)?1 h?1 which is three times higher than that of prototypal cobalt catalyst ( Co0 ) under identical conditions. Moreover, high melt temperature and unimodal molecular weight distribution are the characteristics of the resulting polyethylene. 相似文献
68.
S. Rakib M. Sghyar M. Rafiq J. Sýkora I. Císarová J. Durand A. van der Lee 《Journal of chemical crystallography》2003,33(3):219-222
Iron tri(hydrogenphosphite), Fe(HPO3H)3, crystallizes in both a monoclinic and a hexagonal space group. In this report the structure determination of the hexagonal variant is described: space group P63, a = 8.1690(2) Å, c = 6.9300(2) Å. The structure is slightly disordered, Fe3+ being partially replaced by Al3+, and is very close to that of Fe2(HPO3)3. The only significant difference is that one half of the FeO6 octahedra is missing and that its density is reduced by one half. 相似文献
69.
70.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. 相似文献