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One‐Pot Synthesis of Highly Fluorescent Pyrido[1,2‐a]indole Derivatives through CH/NH Activation: Photophysical Investigations and Application in Cell Imaging
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Srinivas Samala Pragyan Pallavi Ravi Kumar Rajesh K Arigela Gajendra Singh Dr. Ravi Sankar Ampapathi Amulya Priya Dr. Sunando Datta Dr. Abhijit Patra Dr. Bijoy Kundu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(44):14344-14350
We describe a straightforward strategy for the synthesis of strongly fluorescent pyridoindoles by Pd‐catalyzed oxidative annulations of internal alkynes with C‐3 functionalized indoles through C?H/N?H bond activation in a one‐pot tandem process. Mechanistic investigations reveal the preferential activation of N?H indole followed by C?H activation during the cyclization process. Photophysical properties of pyridoindoles exhibited the highest fluorescence quantum yield of nearly 80 %, with emission color varying from blue to green to orange depending on the substructures. Quantum mechanical calculations provide insights into the observed photophysical properties. The strong fluorescence of the pyrido[1,2‐a]indole derivative has been employed in subcellular imaging, which demonstrates its localization in the cell nucleus. 相似文献
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155.
JPC – Journal of Planar Chromatography – Modern TLC - Sida spinosa Linn. (synonyms: S. alba L., S. angustifolia Lam., S. angustifolia Mill.), Malvaceae, is an annual erect, branched... 相似文献
156.
Abimbola P. Oluyori Arun Kumar Shaw Rastogi Preeti Sammajay Reddy Olubunmi Atolani Gabriel A. Olatunji 《Natural product research》2016,30(18):2125-2129
Three antifungal compounds have been isolated for the first time from the peels of Ipomoea batatas Lam. Their structures were established on the basis of 1D and 2D NMR spectra data as well as ESI-MS and IR analysis. Urs-13(18)-ene-3β-yl acetate was found to possess a weak activity against Sporothrix schenckii and Trichophyton metagrophytes fungi with an MIC value of 50 μg/mL each. Stigmasterol and 3-friedelanol were equally active against T. metagrophytes. 相似文献
157.
Synthesis of high aspect ratio quantum-size CdS nanorods and their surface-dependent photoluminescence 总被引:1,自引:0,他引:1
Saunders AE Ghezelbash A Sood P Korgel BA 《Langmuir : the ACS journal of surfaces and colloids》2008,24(16):9043-9049
Colloidal CdS nanorods with diameters near 4 nm and narrow size distributions ( approximately +/-10%) were synthesized up to 300 nm long by a sequential reactant injection technique that utilizes phosophonic acids as capping ligands. The phosphonic acid strongly passivates the nonpolar CdS surfaces and sequential reactant injection provides controlled CdS formation kinetics to enable heterogeneous and facet-selective CdS deposition on the more reactive {002} surfaces. With this process, the nanorod length can be systematically increased by increasing reactant addition to extend nanorod growth. The phosphonic acid concentration, however, is quite important, as "low" concentrations allow radial deposition and branching to occur. These high aspect ratio (>100) CdS nanorods luminesce with relatively high efficiencies of 10.8% quantum yield at room temperature. The luminescence, however, mostly arises from trap-related recombination, and the emission is significantly red-shifted from the absorption edge. Various surface passivation treatments were explored to eliminate trap emission and increase the luminescence quantum yield. Thiol and amine passivation both significantly reduced trap emission and enhanced band-edge emission, but the total luminescence quantum yields dropped significantly, with a maximum measured value of 1.5% for the amine-passivated CdS nanorods. 相似文献
158.
Simon KA Sejwal P Gerecht RB Luk YY 《Langmuir : the ACS journal of surfaces and colloids》2007,23(3):1453-1458
Emulsion systems involving surfactants are mainly driven by the separation of the hydrophobic interactions of the aliphatic chains from the hydrophilic interactions of amphiphilic molecules in water. In this study, we report an emulsion system that does not include amphiphilic molecules but molecules with functional groups that are completely solvated in water. These functional groups give rise to molecular interactions including hydrogen bonding, pi stacking, and salt bridging and are segregated into a dispersion of droplets forming a water-in-water emulsion. This water-in-water emulsion consists of dispersing droplets of a water-solvated biocompatible liquid crystal--disodium cromoglycate (DSCG)--in a continuous aqueous solution containing specific classes of water-soluble polymers. Whereas aqueous solutions of polyols support the formation of emulsions of spherical droplets consisting of lyotropic liquid crystal DSCG with long-term stability (for at least 30 days), aqueous solutions of polyamides afford droplets of DSCG in the shape of prolate ellipsoids that are stable for only 2 days. The DSCG liquid crystal in spherical droplets assumes a radial configuration in which the optical axis of the liquid crystal aligns perpendicular to the surface of the droplets but assumes a tangential configuration in prolate ellipsoids in which the optical axis of the liquid crystal aligns parallel to the surface of the droplet. Other classes of water-soluble polymers including polyethers, polycations, and polyanions do not afford a stable emulsion of DSCG droplets. Both the occurrence and the stability of this unique emulsion system can be rationalized on the basis of the functional groups of the polymer. The different configurations of the liquid crystal (DSCG) droplets were also found to correlate with the strength of the hydrogen bonding that can be formed by the functional groups on the polymer. 相似文献
159.
Two new iridoids 6-O-[2,3-dimethoxy]-trans-cinnamoyl catalpol (1) and 6-O-meta-methoxy-benzoyl catalpol (2) along with a known iridoid picroside 1 (3), two stilbenes quadrangularin A (4) and pallidol (5), quercitin (6), quercitrin (7), beta-sitosterol (8) and beta-sitosterol glycoside (9) were isolated from Cissus quadrangularis Linn. The compounds 3 and 7 are first reported from this plant. The structures were elucidated by analysis of their spectroscopic data and by direct comparison with literature. This is the first reported occurrence of iridoids in C. quadrangularis. 相似文献
160.
R. K. Shukla Preeti Misra Sweta Sharma Nagendra Tomar Pratima Jain 《Journal of the Iranian Chemical Society》2012,9(6):1033-1043
Densities and refractive indices were measured for the binary liquid mixtures formed by benzonitrile, chlorobenzene, benzyl chloride, and benzyl alcohol with benzene at (T = 298.15, 303.15, 308.15 and 313.15 K) and atmospheric pressure over the whole concentration range. The Lorentz–Lorentz mixing rule, the Ramaswami and Anbananthan model, and the model devised by Glinski were used to study the refractive index and molar refractivity. These results have been discussed to study the type of mixing behavior between the mixing molecules. The measured data were fitted to the Redlich–Kister polynomial relation to estimate the binary coefficients and standard errors. Furthermore, the McAllister multibody interaction model is used to correlate the binary refractive index with the experimental findings. It is observed that molar refractivity, molecular interaction, and association constant can be better understood from these models. 相似文献