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Vinod Kumar Gupta Ajay Kumar Jain Zakariyya Ishtaiwi Heinrich Lang Gaurav Maheshwari 《Talanta》2007,73(5):803-811
PVC-based membranes of meso-tetrakis-{4-[tris-(4-allyl dimethylsilyl-phenyl)-silyl]-phenyl}porphyrin (I) and (sal)2trien (II) as electroactive material with dioctylphthalate (DOP), tri-n-butylphosphate (TBP), chloronapthalene (CN), dibutylphthalate (DBP) and dibutyl(butyl) phosphonate (DBBP) as plasticising solvent mediators have been found to act as Ni2+ selective sensor. The best performance was obtained with the sensor having a membrane of composition of I: sodium tetraphenyl borate: PVC in the ratio 5:5:150. The sensor exhibits Nernstian response in the activity range 2.5 × 10−6 to 1.0 × 10−1 M, performs satisfactorily over wide pH range (2–5.5) with a fast response time (8 s). The sensor was found to work satisfactorily in partially non-aqueous media up to 20% (v/v) content of methanol or ethanol and acetone and could be used over a period of 4 months. Potentiometric selectivity coefficients determined by matched potential method (MPM) indicate excellent selectivity for Ni2+ ions. The sensors could be used successfully in the estimation of nickel in different brand of chocolates and also as an indicator electrode in potentiometric titration. 相似文献
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Heinrich Lang Zakariyya Ishtaiwi Tobias Rüffer Robert Mothes Bernhard Walfort 《Journal of organometallic chemistry》2011,696(7):1409-1415
Consecutive synthesis methodologies for the preparation of carbosilanes (Ph)(Me)Si((CH2)3B(OH)2)2 (2), Si(C6H4-4-SiMe2((CH2)3B(OH)2))4 (5), (Ph)(Me)Si((CH2)3OH)2 (3), and Si(C6H4-4-SiMe3−n((CH2)3OH)n)4 (6a, n = 1; 6b, n = 2; 6c, n = 3) are reported. Boronic acids 2 and 5 are accessible by treatment of (Ph)(Me)Si(CH2CHCH2)2 (1) or Si(C6H4-4-SiMe2(CH2CHCH2))4 (4a) with HBBr2·SMe2 followed by addition of water, while 3 and 6 are available by the hydroboration of 1 or Si(C6H4-4-SiMe3−n(CH2CHCH2)n)4 (4a, n = 1; 4b, n = 2; 4c, n = 3) with H3B·SMe2 and subsequent oxidation with H2O2.The single molecular structure of 6a in the solid state is reported. Representative is that 6a crystallized in the chiral non-centrosymmetric space group P212121 forming 2D layers due to intermolecular hydrogen bond formation of the HO functionalities along the crystallographic a and c axes. 相似文献
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Zakariyya Uba Zango Wei Leng Tan Mohamad Abu Bakar 《Journal of Dispersion Science and Technology》2018,39(1):148-154
Halloysite nanotubes (HNTs) were modified with CuO to form CuO-HNT composites. Results revealed that the CuO particles deposited on the HNT have higher specific surface area (SBET) and pore volume compared to unmodified HNT. Application of the composites for the removal of methyl red (MR) dye was investigated. The composites have better removal efficiency than HNT. The data fitted the Freundlich adsorption isotherms. Kinetics of adsorption favored the pseudo-second-order model. Removal efficiency was faster and higher in alkaline conditions. Reusability experiments show that the low-cost composites were effective up to seven cycles. 相似文献
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An efficient synthetic protocol based on a free-radical cascade reaction via 6-exo-trig and 7-endo-trig cyclization processes is described for a new substituted benzoazepinoquinazolinone system which could in principle be used to form the cyclopropanequinone system found in duocarmycins. 相似文献
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