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81.
Saroj K. S. Hazari Debashish Palit Tapashi G. Roy Sukla Rakshit Julio Zukerman-Schpector Edward R. T. Tiekink 《Journal of chemical crystallography》2009,39(4):261-265
Abstract The title dinuclear complex, [(cis-MoO2L)(μ-O)(cis-MoOL(OH2)], was characterized as a chloroform solvate. In this structure, one Mo atom features a cis-[MoO2]2+ core to which is also bonded a dinegative, tridentate S-benzyl 3-(2-hydroxyphenyl)methylenedithiocarbazate ligand (= L), via sulfur-, oxygen-, and nitrogen-donors, and a water molecule
completes the distorted octahedral coordination geometry. A similar NO4S donor set is found for the other Mo atom but in this case, the water molecule is substituted by a bridging oxo atom derived
from the first Mo species. Two dimers associate via cooperative O–H⋯O hydrogen bonds to form a supramolecular dimer which,
in turn, are linked into supramolecular chains via O–H⋯N hydrogen bonding. The complex crystallizes in the triclinic space
group P-1 with a = 10.4714(12) ?, b = 10.7627(14) ?, c = 16.708(2) ?, α = 87.916(7)°, β = 76.249(6)°, γ = 83.610(7)°, and Z = 2.
Index Abstract Dinuclear [(cis-MoO2L)(μ-O)(cis-MoOL(OH2)], characterized as a chloroform solvate, with octahedral Mo centers, are connected into supramolecular dimers via O–H⋯O
hydrogen bonding which are connected via O–H⋯N hydrogen bonds into chains.
相似文献
82.
A. Palit A. Panchenko N. G. Migranov A. Bhadra K. K. Nandi 《International Journal of Theoretical Physics》2009,48(5):1271-1289
Phase space method provides a novel way for deducing qualitative features of nonlinear differential equations without actually
solving them. The method is applied here for analyzing stability of circular orbits of test particles in various physically
interesting environments. The approach is shown to work in a revealing way in Schwarzschild spacetime. All relevant conclusions
about circular orbits in the Schwarzschild-de Sitter spacetime are shown to be remarkably encoded in a single parameter. The analysis in the rotating Kerr black hole readily exposes information as to how stability depends on the ratio
of source rotation to particle angular momentum. As a wider application, it is exemplified how the analysis reveals useful
information when applied to motion in a refractive medium, for instance, that of optical black holes. 相似文献
83.
Non-zero dispersion shifted fibers (NZ-DSFs) find extensive use in wavelength division multiplexed (WDM) system as it reduces the non-linear effects like four-wave mixing (FWM) generation. A depressed clad graded index fiber with a central dip in the refractive index profile, as well as without dip, has been modeled to perform as an NZ-DSF using the spot size optimization technique. The performance characteristics of the proposed NZ-DSF have been studied by changing different fiber parameters; such as inner core radius (a), relative refractive index differences (Δ+), normalized end position of depressed clad (C), depression parameter (ρ), etc. for a given value of Petermann-2 spot size . By suitably adjusting the fiber parameters, the effective core areas (Aeff) as simulated here are very large (80 μm2) so that the effect of non-linearities upon them can be minimized. These NZ-DSFs have also been optimized for WDM transmission system. The dispersion slopes of the proposed fibers with and without dip have been estimated which are comparable with the reported results. 相似文献
84.
85.
Adrich P Klimkiewicz A Fallot M Boretzky K Aumann T Cortina-Gil D Pramanik UD Elze TW Emling H Geissel H Hellström M Jones KL Kratz JV Kulessa R Leifels Y Nociforo C Palit R Simon H Surówka G Sümmerer K Waluś W;LANDS-FRS Collaboration 《Physical review letters》2005,95(13):132501
The dipole strength distribution above the one-neutron separation energy was measured in the unstable 130Sn and the double-magic 132Sn isotopes. The results were deduced from Coulomb dissociation of secondary Sn beams with energies around 500 MeV/nucleon, produced by in-flight fission of a primary 238U beam. In addition to the giant dipole resonance, a resonancelike structure ("pygmy resonance") is observed at a lower excitation energy around 10 MeV exhausting a few percent of the isovector E1 energy-weighted sum rule. The results are discussed in the context of a predicted new dipole mode of excess neutrons oscillating out of phase with the core nucleons. 相似文献
86.
B. M. Mandal U. S. Nandi S. R. Palit 《Journal of polymer science. Part A, Polymer chemistry》1970,8(1):67-76
The rate of polymerization Rp of methyl methacrylate initiated by Fe(CIO4)3 and thiourea (TU) in tert-butyl alcohol is indepenent of [Fe(III)] and [TU] in the concentration range studied. In contrast to Rp, the degree of polymerization DP changes markedly with the change in the initiator concentration. DP is overwhelmingly lower than is expected in a standard radical polymerization at the same Rp. Further, Rp is proportional to the square of the monomer concentration. Initiation efficiency is less than one. Independent experiments proved that in the azobisisobutyronitrile-initiated polymerization the Rp and DP are negligibly affected by [Fe(CIO4)3] or [TU], though high [TU] brings about high induction periods. The results of Fe(III)-TU-initiated polymerization have been interpreted in terms of the predominant termination of polymer radicals by primary radicals. 相似文献
87.
Arun K. Sarkar Santi R. Palit 《Journal of polymer science. Part A, Polymer chemistry》1980,18(2):691-699
A search has been made for electroinitiators of postpolymerization. A number of hydroxycarboxylic acids and some of their sodium salts have been found to be quite efficient. Factors controlling the rate of polymerization and yield have been described. Surprisingly, citric acid, though not an electroinitiator of polymerization, is a good initiator of postpolymerization. Other active species that deserve mention are tartaric acid and its salts. A free radical mechanism involving formation of oligomeric initiator fragments, growth by attachment of imbibed monomer, and termination by chain transfer has been proposed to explain the observed facts. 相似文献
88.
To maximize the production of esters (E), keto (K) and keto-ester (KE) by esterification and ketalization of levulinic acid (LA) has been reacted using diols such as 1,2-propane diol (PDOL),1,2-ethane diol (EDOL), and 1,2,3-propane triol or glycerol (TRIOL) with desilicated Hβ. This work aims to assess the conversion and selectivity for the production of esters using conventional and microwave-irradiated (MWI) reactors. Catalysts characterizations were performed using NH3-temperature programme desorption, Brunauer, Emmett and Teller surface area (BET), Barrett, Joyner, and Halenda (BJH), scanning electron microscope, transmission electron microscope, and dynamic light scattering. Operating parameters such as reaction temperature (170–180°C), reaction time (20–80 min), feed composition (LA:PDOL/EDOL/TRIOL, 1:8/10/12), and microwave energy (300–500 watt) have been systematically investigated. Note that 99–100% conversion was achieved with the product selectivity of E (40%), K (30%), and KE (30%) with1,2-EDOL; E (56%), K (2%), and KE (17%) with 1,2-PDOL; E (69%), K(0%), and KE (22%) with TRIOL using D-Hβ as a solid catalyst in an MWI reactor. Reaction paths and kinetics were studied using pseudo-homogeneous (PH) model. 相似文献
89.
Rakesh Biswas Sumit Naskar Surya Ghosh Prof. Dr. Mousumi Das Prof. Dr. Supratim Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(60):13595-13600
Signal transduction is essential for the survival of living organisms, because it allows them to respond to the changes in external environments. In artificial systems, signal transduction has been exploited for the highly sensitive detection of analytes. Herein, a remarkable signal transduction, upon ATP binding, in the multivalent fibrillar nanoaggregates of anthracene conjugated imidazolium receptors is reported. The aggregates of one particular amphiphilic receptor sensed ATP in high pm concentrations with one ATP molecule essentially quenching the emission of thousands of receptors. A cooperative merging of the multivalent binding and signal transduction led to this superquenching and translated to an outstanding enhancement of more than a millionfold in the sensitivity of ATP detection by the nanoaggregates; in comparison to the “molecular” imidazolium receptors. Furthermore, an exceptional selectivity to ATP over other nucleotides was demonstrated. 相似文献
90.
Chiral rotation observed in 128Cs is studied using the newly developed microscopic triaxial projected shell model (TPSM) approach. The observed energy levels and the electromagnetic transition probabilities of the nearly degenerate chiral dipole bands in this isotope are well reproduced by the present model. This demonstrates the broad applicability of the TPSM approach, based on a schematic interaction and angular-momentum projection technique, to explain a variety of low- and high-spin phenomena in triaxial rotating nuclei. 相似文献