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991.
The reactions of bis(cyclopentadienyl)titanium(IV) chloride with a new class of bis(thiosemicarbazones) (H2L), derived by condensing isatin with different N(4)‐substituted thiosemicarbazides, have been studied both by a conventional stirring method and also using microwave technology. Binuclear products of type [{(η5‐C5H5)2TiCl} 2(L)] have been isolated in both cases. Tentative structural conclusions are drawn for the reaction products based upon analysis, electrical conductance, magnetic moment and spectral (UV‐visible, IR, 1H NMR and 13C NMR) data. FAB mass spectra of these compounds were also recorded to confirm the binuclear structures. Studies were conducted to assess the growth inhibiting potential of the ligands and complexes against various fungal, viral and bacterial strains. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
992.
We present a simple technique to characterize and image the distribution of local elastic property using ultrasonic atomic force microscope (UAFM). We interpret the UAFM images using simple arguments. We have demonstrated the capability of the UAFM technique to image the distribution of the local elastic property of the sample surface and semi-quantitatively map the local stiffness of the sample surface using a few selected samples. The local stiffness of the sample surface was obtained by measuring the changes in the frequency of contact resonance peak values and could verify the same using force-distance measurement at the same regions on the sample surface. 相似文献
993.
Sucharita Banerjee Anthony J. Camodeca Gregory G. Griffin Christopher G. Hamaker Shawn R. Hitchcock 《Tetrahedron: Asymmetry》2010,21(5):549-557
Using N-benzylephedrine as a model, a collection of N-arylmethylephedrine derivatives has been prepared. These derivatives were prepared by treatment of ephedrine with selected aldehydes to create oxazolidines 8a–e. Reduction of the oxazolidines with lithium aluminum hydride afforded the target β-amino alcohols 9a–e. When applied in the catalytic asymmetric addition of diethylzinc to aldehydes and diphenylphosphinoylimines, the derivatives yielded product enantioselectivities that were comparable to those of N-benzylephedrine. An N-cyclohexylmethylephedrine derivative was also prepared; this β-aminoalcohol did not perform well in the catalytic addition of diethylzinc to 2-naphthaldehyde, thus suggesting that the aromatic motif is important in terms of maintaining a reasonable level of asymmetric induction. Finally, N-benzyl-N-methyl-2-amino-1,2-diphenyl-1-ethanol, an analogue of the N-benzylephedrine derivative, was prepared. This compound yielded comparable enantioselectivities in the catalytic asymmetric addition when employed as a ligand. 相似文献
994.
We have proposed some new designs of reversible sequential circuits using NCT gate library and compared them with the earlier
proposals. It has been shown that the present proposals have lower gate complexities and lower number of garbage bits compared
to the earlier proposals. We have addressed some conceptual issues related to the feedback and the choice of gate library.
Further it is shown that the proposed quantum / reversible circuits can be implemented optically. 相似文献
995.
Subhadeep Saha Eva‐Maria Schön Prof. Dr. Carlos Cativiela Prof. Dr. David Díaz Díaz Dr. Rahul Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(29):9562-9568
Oxalic acid has been proven to be the lowest molecular weight organic ligand able to form robust supramolecular metallogel networks in the presence of metal salts. In particular, two novel multifunctional metallogels were readily prepared at room temperature by simple mixing of stock solutions of CuII acetate monohydrate or CuII perchlorate hexahydrate and oxalic acid dihydrate. Formation of different polymorphs and unprecedented proton conduction under anhydrous conditions were also demonstrated with some of these materials. 相似文献
996.
An expeditious and concise method has been described for the synthesis of ailanthoidol through convergent route starting from vanillin. The protocol involving intramolecular Wittig as a key reaction afforded ailanthoidol in overall high yield. 相似文献
997.
Relativistic configuration interaction calculations are carried out to study the electronic structure and spectroscopic properties of InI and InI+. Potential energy curves of the ground and a number of low‐lying states are constructed. Spectroscopic parameters of the bound states of both species are computed and compared with the experimental and other theoretical data. Effects of spin‐orbit coupling on the spectroscopic properties are studied. Because of the presence of the heavy atoms the effect is large. The spin‐orbit splitting of the ground state (X2Π) of InI+ is more than 8350 cm?1. As a result of the strong spin‐orbit interaction between X2Π and A2Σ+ of InI+, the potential energy curve of A2Σ becomes repulsive. Radiative lifetimes for the spin‐forbidden transitions such as A3Π?X1Σ and B3Π1 ?X1Σ of InI and spin‐allowed transitions such as B2Σ+?A2Σ+, C2Π?A2Σ+, and B2Σ+?X2Π are calculated. Vertical and adiabatic ionization energies of InI and the electric dipole moments of both the neutral and ionic species are estimated. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
998.
Sundman O Persson P Banerjee D Öhman LO 《Journal of colloid and interface science》2012,374(1):250-257
The adsorption qualities of GaO(4)Al(12)(OH)(24)(H(2)O)(12)(7+), a polycation with ε-Keggin structure, and its stability in contact with anionic cellulosic materials, was investigated under different concentration and ionic strength conditions. The cellulosic materials employed were two different fully bleached fibre materials, carboxyl methyl cellulose (CMC), and a spin-coated cellulose model surface. As analytical techniques, pH-measurements, potentiometric titrations, ICP-OES, QCM-D, equilibrium calculations and Extended X-ray Absorption Fine Structure (EXAFS) were used. The adsorption is substantial and the addition of GaO(4)Al(12)(OH)(24)(H(2)O)(12)(7+) to a fibre suspension results in a rapid decrease in pH, followed by a small and slow increase in pH. This behaviour can be explained as due to a rapid and strong (log β>2) equilibrium adsorption of intact GaO(4)Al(12)(OH)(24)(H(2)O)(12)(7+) ions, followed by a slow, and minor, 3-8%, decomposition into different monomers. Alternative layer by layer adsorption of this ion, and CMC, on a spin-coated cellulose model surface constitutes further evidence for the strong interactions between the anionic cellulose materials and GaO(4)Al(12)(OH)(24)(H(2)O)(12)(7+). It is shown that the adsorption observed could not be described as due to an unspecific Donnan adsorption behaviour, neither of GaO(4)Al(12)(OH)(24)(H(2)O)(12)(7+) nor Ga and Al monomers, and specific surface complex formation is therefore discussed and applied. The (≡COO)(7)GaO(4)Al(12)(OH)(24)(H(2)O)(12) species found to explain the pH- and metal adsorption data should be considered strictly as a stoichiometric entity. 相似文献
999.
Sayani Mitra Dheeraj Thawrani Priyam Banerjee Ratan Gachhui Joydeep Mukherjee 《Applied biochemistry and biotechnology》2012,166(8):1991-2006
The aim of the investigation was to ascertain if surface attachment of Candida famata and aeration enhanced riboflavin production. A newly designed polymethylmethacrylate (PMMA) conico-cylindrical flask (CCF)
holding eight equidistantly spaced rectangular strips mounted radially on a circular disk allowed comparison of riboflavin
production between CCFs with hydrophobic surface (PMMA-CCF), hydrophilic glass surface (GS-CCF), and 500-ml Erlenmeyer flask
(EF). Riboflavin production (mg/l) increased from 12.79 to 289.96, from 54.44 to 238.14, and from 36.98 to 158.71 in the GS-CCF,
EF, and PMMA-CCF, respectively, when C. famata was grown as biofilm-induced cultures in contrast to traditional planktonic culture. Production was correlated with biofilm
formation and planktonic growth was suppressed in cultivations that allowed higher biofilm formation. Enhanced aeration increased
riboflavin production in hydrophilic vessels. Temporal pattern of biofilm progression based on two-channel fluorescence detection
of extracellular polymeric substances and whole cells in a confocal laser scanning microscope followed by application of PHLIP
and ImageJ volume viewer software demonstrated early maturity of a well-developed, stable biofilm on glass in contrast to
PMMA surface. A strong correlation between hydrophilic reactor surface, aeration, biofilm formation, and riboflavin production
was established in C. famata. Biofilm culture is a new-found means to improve riboflavin production by C. famata. 相似文献
1000.
Adhikari B Biswas A Banerjee A 《Langmuir : the ACS journal of surfaces and colloids》2012,28(2):1460-1469
In the presence of a small amount of a proteinous amino acid (arginine/tryptophan/histidine) or a nucleoside (adenosine/guanosine/cytidine), graphene oxide (GO) forms supramolecular stable hydrogels. These hydrogels have been characterized by field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Raman spectroscopy, and rheology. The morphology of the hydrogel reveals the presence of nanofibers and nanosheets. This suggests the supramolecular aggregation of GO in the presence of an amino acid/nucleoside. Rheological studies of arginine containing a GO-based hydrogel show a very high G' value (6.058 × 10(4) Pa), indicating the rigid, solid-like behavior of this gel. One of these hydrogels (GO-tryptophan) has been successfully utilized for the in situ synthesis and stabilization of Au nanoparticles (Au NPs) within the hydrogel matrix without the presence of any other external reducing and stabilizing agents to make Au NPs containing the GO-based nanohybrid material. The Au NPs containing the hybrid hydrogel has been characterized by using UV/vis spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). In this study, gold salt (Au(3+)) has been bioreduced by the tryptophan within the hydrogel. This is a facile "green chemical" method of preparing the GO-based nanohybrid material within the hydrogel matrix. The significance of this method is the in situ reduction of gold salt within the gel phase, and this helps to decorate the nascently formed Au NPs almost homogeneously and uniformly on the surface of the GO nanosheets within the gel matrix. 相似文献