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1.
Thyagarajan S Shay DT Incarvito CD Rheingold AL Theopold KH 《Journal of the American Chemical Society》2003,125(15):4440-4441
Reaction of TpR,MeCo(I) dinitrogen complexes (R = iPr, tBu) with trimethylsilyl azide yields structurally characterized compounds that imply the formation of reactive intermediates of the type TpR,MeCo=NSiMe3. These cobalt imido species apparently abstract hydrogen from the 3-substituent of the Tp-ligand, leading to the formation of amido complexes accompanied by either Co-C bond formation (R = tBu) or C-C bond formation (R = iPr). 相似文献
2.
Magnesium perchlorate has been found to be an efficient catalyst for the synthesis of imines and phenylhydrazones by the reaction of carbonyl compounds with amines and phenylhydrazine in high yields at room temperatures and in short times. The condensation of less electrophilic carbonyl compounds with poorly nucleophilic amines affords the imines in excellent yields. 相似文献
3.
Karishna C. Joshi Anshu Dandia Sunita Baweja Amitabh Joshi 《Journal of heterocyclic chemistry》1989,26(4):1097-1099
An elegant one-step synthesis of two novel spiro ring systems viz: spiro[3H-indole-3,4′-(2′-amino-3′-carbonitrile-[4′H]-pyrano[3,2-c]benzopyran)]-2,5′(1H)-dione8 and spiro[(2-amino-3-carbonitrile-indeno[1,2-b]pyran)-4(5H)>3′-[3H]indole]-2′,5(1′H)-diones in 80–85% yields is described. The spiro heterocycles were prepared by the reactions of fluorine containing 3-dicyanomethylene-2H-indol-2-ones with 4-hydroxy-2H-1-benzopyran-2-one and 1H-indene-1,3(2H)-dione respectively. The synthesized compounds have been characterized on the basis of elemental analyses, ir, pmr, 19F nmr and mass spectral data. 相似文献
4.
Anuradha Mishra Malvika Bajpai Sunita Pal Monika Agrawal Sushant Pandey 《Colloid and polymer science》2006,285(2):161-168
The application of Tamarindus
indica seed mucilage (Tam), a food grade polysaccharide, and its acrylamide grafted copolymer as flocculants was assessed for the first time for removal of various types of dyes from model textile wastewater containing azo, basic, and reactive dyes. Acrylamide grafted T. indica mucilage (Tam-g-PAM) was obtained by ceric ion initiated polymerization technique. A series of contact time experiments were conducted to assess the system variables such as concentrations of mucilage and dyes and pH. These flocculants reduce the dye concentration by flocculation and settling. The grafted copolymer, Tam-g-PAM showed better results for dye removal. The optimal flocculant concentration, which was required to effect flocculation, was independent of dye concentration within the range examined. Both the flocculants performed better for removal of azo dyes than for reactive and basic dyes. 相似文献
5.
Subhash C. Jain Pankaj Khanna Sunita Bhagat Manish Jain Rajeev Sakhuja 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1829-1839
The reaction of indol-2,3-diones ( 1a–i ) with 5-aminoindazole ( 2 ) has resulted in the formation of hitherto unknown 3-(indazol-5-yl)iminoindol-2-ones ( 3a–i ) in quantitative yields which, on 1,3-dipolar cyclocondensation with mercaptoacetic acid ( 4 ), has afforded a series of new spiro heterocycles, 3′-(indazol-5-yl) spiro[3H, indol-3, 2′ -thiazolidine]-2,4′-diones* ( 5a–i ). 相似文献
6.
The reaction of 1H‐indol‐2,3‐diones with 1,6‐dibromohexane has resulted in the formation of new 1H‐indol‐2,3‐diones‐1,1′‐(1,6‐hexanediyl)bis in quantitative yields. These compounds have been used for the synthesis of novel [3′‐(2,3‐dimethyl‐5‐oxo‐1‐phenyl‐3‐pyrazolin‐4‐yl)spiro[3H‐indol‐3,2′‐thiazolidine]‐2,4′‐dione]‐1,1′‐(1,6‐hexanediyl)bis via bis Schiff's bases, [3‐(2,3‐dimethyl‐5‐oxo‐1‐phenyl‐3‐pyrazolin‐4‐yl) imino‐1H‐indol‐2‐one]‐1,1′‐(1,6‐hexanediyl)bis. 相似文献
7.
Aradhya Dev Srivastav Vireshwar Singh Deepak Singh Sunita Singh Suresh Kumar Patel Dilip Kumar Sudeep Yadav Balendu Shekher Giri Dhananjay Singh 《印度化学会志》2022,99(8):100632
Nelumbo nucifera leaves are rich source of natural wax possessing super-hydrophobic properties. It provides protection to them from ecological turbulences and climatic wear and tear. In this study, various experiments have been conducted to observe the yield of extraction and the determination of various functional groups, which are present in natural wax, derived from Nelumbo nucifera leaves. The natural wax has been extracted from lotus leaves through non-polar (hexane) and polar (ethanol) solvent via different extraction methods. The superhydrophobic wax has been successfully extracted with hexane. Whereas, ethanol did not extract the water-repellent wax of lotus leaf. Considering the cumulative amount, i.e. (desired + undesired), the maceration shows the extraction of 2.9% (%w/w, through hexane) and 10.2% (%w/w, through ethanol), while it was found 2.5% (%w/w, cycle period 15 min) and 9.0% (%w/w, cycle period 26 min) respectively, in case of Soxhlet extraction technique. For this specific case of natural wax recovery from biomass (lotus leaf), the maceration (traditional method) resulted a little bit superior extraction yield in comparison to the Soxhlet extraction method for extraction of crude wax. In the case of non-polar solvent (hexane), an extraction yield of 1.97% (%w/w) through maceration method was observed while in the case of non-polar solvent (ethanol), an extraction yield of 1.62% (%w/w) through Soxhlet extraction was observed. The TLC analysis on both types of extracts was performed. For the detection of various hydrocarbon chains in the crude wax extracts, FTIR was also performed. Topography of wax surface and wax-coated waterproof fabric was compared through SEM. 相似文献
8.
Transport of liquids using superhydrophobic aerogels 总被引:9,自引:0,他引:9
Venkateswara Rao A Kulkarni MM Bhagat SD 《Journal of colloid and interface science》2005,285(1):413-418
The experimental results of the studies on the transportation of water droplets on a superhydrophobic silica aerogel-powder-coated surface are reported. The superhydrophobic silica aerogels were prepared using sol-gel processing of methyltrimethoxysilane (MTMS) precursor, methanol (MeOH) solvent, and base (NH4OH)-catalyzed water followed by supercritical drying using methanol solvent. The molar ratio of NH4OH/MTMS, H2O/MTMS, and MeOH/MTMS were varied from 1.7x10(-1) to 3.5x10(-1), 2 to 8, and 1.7 to 14, respectively, to find out the best-quality aerogels in terms of higher hydrophobicity and high droplet velocity. A specially built device was used for the measurement of velocity of water droplet of size 2.8 mm (+/-0.2 mm) on an inclined surface coated with superhydrophobic aerogel powder. Liquid marbles were prepared by rolling water droplets on aerogel powder and the marble(s) velocities on a noncoated inclined surface were compared with that of the water droplets. It was observed that the microstructure of the aerogel affects the droplet as well as marble velocities considerably. For an aerogel with uniform and smaller particles, the water droplet and marble velocities were observed to be maximum, i.e., 144 and 123 cm/s, respectively, whereas for the aerogels with bigger and nonuniform particles, the water droplet and marble velocities were observed to be minimum, i.e., 92 and 82 cm/s, respectively. The results have been discussed by taking into account the contact angles and microstructural observations. 相似文献
9.
Reaction of cis-[PtCl2(AsPh3)2] with excess sodium sulfide in benzene gave the triphenylarsine analogue of the well-known metalloligand [Pt2(μ-S)2(PPh3)4] as an orange solid.The compound was characterised by detailed mass spectrometry studies, and by conversion to various alkylated and metallated derivatives.The sulfide ligands in [Pt2(μ-S)2(AsPh3)4] are less basic than the triphenylphosphine analogue, and the complex gives a relatively weak [M+H]+ ion in the positive-ion electrospray (ESI) mass spectrum, compared with the phosphine analogue.Methylation of an equimolar mixture of [Pt2(μ-S)2(PPh3)4] and [Pt2(μ-S)2(AsPh3)4] with MeI gave the species [Pt2(μ-S)(μ-SMe)(AsPh3)4]+ and [Pt2(μ-SMe)2(PPh3)3I]+, indicating a reduced tendency for the sulfide of [Pt2(μ-S)(μ-SMe)(AsPh3)4]+ to undergo alkylation.The lability of the arsine ligands is confirmed by the reaction of an equimolar mixture of [Pt2(μ-S)2(PPh3)4] and [Pt2(μ-S)2(AsPh3)4] with n-butyl chloride, giving [Pt2(μ-S)(μ-SBu)(EPh3)4]+ (E = P, As), which with Me2SO4 gave a mixture of [Pt2(μ-SMe)(μ-SBu)(PPh3)4]2+ and [Pt2(μ-SMe)(μ-SBu)(AsPh3)3Cl]+.Reactivity towards 1,2-dichloroethane follows a similar pattern.The formation and ESI MS detection of mixed phosphine-arsine {Pt2S2} species of the type[Pt2(μ-S)2(AsPh3)n(PPh3)4−n] is also discussed. Coordination chemistry of [Pt2(μ-S)2(AsPh3)4] towards a range of metal-chloride substrates, forming sulfide-bridged trinuclear aggregates, has also been probed using ESI MS, and found to be similar to the phosphine analogue. The X-ray crystal structure of [Pt2(μ-S)2(AsPh3)4Pt(cod)](PF6)2 (cod = 1,5-cyclo-octadiene) has been determined for comparison with the (previously reported) triphenylphosphine analogue. ESI MS is a powerful tool in exploring the chemistry of this system; in some cases the derivatising agent p-bromobenzyl bromide is used to convert sparingly soluble and/or poorly ionising {Pt2S2} species into soluble, charged derivatives for MS analysis. 相似文献
10.
Three and four bond order couplings between carbonyl carbon and other neighboring protons have been investigated in detail with the help of 2D heteronuclear multiple bond correlation (HMBC) spectrum. The methine and methylene protons in pentad and tetrad configuration were found to couple with carbonyl carbon. The intensity ratio of methylene protons’ cross peaks in HMBC spectrum shows that 50% of poly methyl acrylate (PMA) is in isotactic and 50% is in syndiotactic configuration. The configurational analysis was mainly carried out with the help of 2D HMBC spectrum. 相似文献