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51.
Manas Mahapatra Arnab Dutta Joy Sankar Deb Roy Ujjal Das Dr. Snehasis Banerjee Prof. Sanjit Dey Dr. Pijush Kanti Chattopadhyay Prof. Dilip K. Maiti Dr. Nayan Ranjan Singha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(2):502-516
To circumvent costly fluorescent labeling, five nonconventional, multifunctional, intrinsically fluorescent aliphatic terpolymers ( 1 – 5 ) have been synthesized by C−C/C−N-coupled, solution polymerization of two non-emissive monomers with protrusions of fluorophore monomers generated in situ. These scalable terpolymers were suitable for sensing and high-performance exclusion of CuII, logic function, and bioimaging. The structures of the terpolymers, in situ attachment of fluorescent monomers, aggregation-induced enhanced emission, bioimaging ability, and super adsorption were investigated by 1H and 13C NMR, EPR, FTIR, X-ray photoelectron, UV/Vis, and atomic absorption spectroscopy, thermogravimetric analysis, high-resolution transmission electron microscopy, dynamic light scattering, solid-state fluorescence, fluorescence imaging, and fluorescence lifetime measurements, as well as by isotherm, kinetics, and thermodynamic studies. The geometries and electronic structures of the fluorophores and the absorption and emission properties of the terpolymers were examined by DFT, time-dependent DFT, and natural transition orbital analyses. For 1 , 2 , and 5 , the limits of detection were determined to be 1.03×10−7, 1.65×10−7, and 1.77×10−7 m , respectively, and the maximum adsorption capacities are 1575.21, 1433.70, and 1472.21 mg g−1, respectively. 相似文献
52.
Latin hypercube designs have been found very useful for designing computer experiments. In recent years, several methods of constructing orthogonal Latin hypercube designs have been proposed in the literature. In this article, we report some more results on the construction of orthogonal Latin hypercubes which result in several new designs. 相似文献
53.
A quantum hydrodynamical study is made of the dynamical changes of a helium atom interacting with lasers of two different
intensities, but having the same frequency. Under the intense laser field, electron density oozes out of the helium atom by
absorbing laser photons and getting promoted to higher excited states including the continuum. Under the superintense field,
electron density partly moves away from the helium nucleus but remains in the “quasi-bound” dressed states along with the
laser field, thus suppressing ionization. 相似文献
54.
55.
Dr. Krishna Kanti Dey Frances Ying Pong Dr. Jens Breffke Dr. Ryan Pavlick Dr. Emmanuel Hatzakis Dr. Carlos Pacheco Dr. Ayusman Sen 《Angewandte Chemie (International ed. in English)》2016,55(3):1113-1117
While momentum transfer from active particles to their immediate surroundings has been studied for both synthetic and biological micron‐scale systems, a similar phenomenon was presumed unlikely to exist at smaller length scales due to the dominance of viscosity in the ultralow Reynolds number regime. Using diffusion NMR spectroscopy, we studied the motion of two passive tracers—tetramethylsilane and benzene—dissolved in an organic solution of active Grubbs catalyst. Significant enhancements in diffusion were observed for both the tracers and the catalyst as a function of reaction rate. A similar behavior was also observed for the enzyme urease in aqueous solution. Surprisingly, momentum transfer at the molecular scale closely resembles that reported for microscale systems and appears to be independent of swimming mechanism. Our work provides new insight into the role of active particles on advection and mixing at the Ångström scale. 相似文献
56.
Sarkar S Biswas S Dey K 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,71(4):1555-1561
Four homodinuclear complexes of Ni(II)-Ni(II), Cu(II)-Cu(II), Co(II)-Co(II) and Co(III)-Co(II) and five heterodinuclear complexes of Co(III)-Zn(II), Co(III)-Cu(II), Co(III)-Ni(II), Cu(II)-Zn(II) and Zn(II)-Cu(II) with the octadentate Schiff base compartmental ligand 1,8-N-bis(3-carboxy)disalicylidene-3,6-diazaoctane-1,8-diamine (H4fsatrien) have been synthesized. The complexes have been characterized with the help of elemental analyses, molecular weights, molar conductances, magnetic susceptibilities and spectroscopic (UV-vis, IR, ESR) data. Cryomagnetic data also helped to elucidate the structural features of the Cu(II) complexes. 相似文献
57.
Dey A Hocking RK Larsen P Borovik AS Hodgson KO Hedman B Solomon EI 《Journal of the American Chemical Society》2006,128(30):9825-9833
Iron L-edge, iron K-edge, and sulfur K-edge X-ray absorption spectroscopy was performed on a series of compounds [Fe(III)H(3)buea(X)](n-) (X = S(2-), O(2-), OH(-)). The experimentally determined electronic structures were used to correlate to density functional theory calculations. Calculations supported by the data were then used to compare the metal-ligand bonding and to evaluate the effects of H-bonding in Fe(III)(-)O vs Fe(III)(-)S complexes. It was found that the Fe(III)(-)O bond, while less covalent, is stronger than the Fe(III)(-)S bond. This dominantly reflects the larger ionic contribution to the Fe(III)(-)O bond. The H-bonding energy (for three H-bonds) was estimated to be -25 kcal/mol for the oxo as compared to -12 kcal/mol for the sulfide ligand. This difference is attributed to the larger charge density on the oxo ligand resulting from the lower covalency of the Fe-O bond. These results were extended to consider an Fe(IV)(-)O complex with the same ligand environment. It was found that hydrogen bonding to Fe(IV)(-)O is less energetically favorable than that to Fe(III)(-)O, which reflects the highly covalent nature of the Fe(IV)(-)O bond. 相似文献
58.
A new crystal-engineering motif has been developed where a ditopic receptor 1 shows a novel syn-syn hydrogen-bonded polymeric supramolecular complex (Fig. 4b) (instead of a 1:1 dimeric syn-syn or polymeric syn-anti complex) giving rise to a hydrogen-bonded stair-like polymeric ribbon structure between the binding groups of the receptor pyridine amide and the carboxyl groups of the guest substrate. 相似文献
59.
Abstract Xanthobilirubinic acid, a model dipyrrinone for one-half of the bilirubin molecule in photochemical and metabolism studies,
is more polar than bilirubin and insoluble in water and in chloroform. Replacing the β-alkyl substituents on the lactam ring
of xanthobilirubinic acid with methyl-capped ethylene glycol, diethylene glycol, and triethylene glycol (PEG) groups steadily
increased the water solubility of the pigment so that the last is completely soluble in both water and chloroform. Synthesized
by base-catalyzed condensation of the corresponding methyl-capped 3,4-diPEG-pyrrolin-2-one with 3,5-dimethyl-4(2-ethoxycarbonylethyl)-2-formyl-1H-pyrrole, these new PEGylated analogs of xanthobilirubinic acid are yellow-colored dipyrrinones that form intermolecular hydrogen-bonded
dimers in chloroform solution but are monomeric in methanol and water, as revealed by 1H NMR spectroscopy and vapor pressure osmometry. Methyl xanthobilirubinate has served as a synthetic precursor to bilirubinoids;
its amphiphilic PEGylated analogs suggest a route to water-soluble bilirubinoids and biliverdinoids.
Graphical abstract
相似文献
60.
Susobhan Biswas Saikat Sarkar Ian M. Steele Sougata Sarkar Golam Mostafa Bijali Bikash Bhaumik Kamalendu Dey 《Polyhedron》2007
The reaction of phenylmercury(II) acetate and cadmium(II) acetate with a refluxed solution of diacetylmonoxime and morpholine N-thiohydrazide formed a novel phenylmercury(II) complex, [PhHg(Hdammthiol)] (1) and a cadmium(II) complex, [Cd(Hdammthiol)2] (2), respectively (where H2dammthiol is the thiol form of diacetylmonoximemorpholine N-thiohydrazone (Hdammth) formed by the condensation of diacetylmonoxime and morpholine N-thiohydrazide in the presence of phenylmercury(II) and cadmium(II) ions). The complexes were characterised by elemental analyses and spectral data (electronic, infrared and 1H NMR) and also by X-ray crystal structure analysis. The X-ray crystallography shows that the phenylmercury(II) complex attained a tricoordinated distorted T-shaped structure, while the cadmium(II) complex attained a trapezoidal bipyramidal geometry. The phenylmercury(II) complex forms a two-dimensional sheet via C–H?O and O–H?N hydrogen bonding and also forms a two-dimensional supramolecular dimer, having C–H?π synthons. Intermolecular C–H?O and O–H?O hydrogen bonding of the cadmium(II) complex forms a two-dimensional supramolecular sheet along the bc plane and posses an impressively short intermolecular C(sp3)?O(sp3) contact. 相似文献