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81.
Induced Correspondence of a Local π‐Aromatic Sextet in Heteroannulenes: Synthesis and Characterization
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Abhijit Mallick Juwon Oh Prof. Dr. Dongho Kim Masatoshi Ishida Prof. Dr. Hiroyuki Furuta Prof. Dr. Harapriya Rath 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(16):5504-5508
Acid‐catalyzed [3+3] condensation reactions of two hitherto unknown tripyrrane moieties with pentafluorobenzaldehyde has led to the formation of new generation heteroannulene (4.1.4.1) and mutant heteroannulene (1.1.1.1.1.1). Inclusion of local π‐aromatic sextets, namely the N‐methyl pyrrole rings through β,β‐linkages and α,β‐linkages, has led to the isolation of first ever heteroannulenes cross‐conjugated at four points and two points respectively within the macrocycles. 相似文献
82.
Polymer‐supported palladium was synthesized by applying a single‐step wet chemical synthesis route and the resultant composite material was characterized by means of various techniques. Infrared and UV–visible spectra provided information on the chemical structure of the polymer. Microscopy techniques showed the general morphology of the polymer. The oxidation state of palladium was determined using the X‐ray photoelectron spectroscopy method. The synthesized material was applied as a heterogeneous catalyst for the Heck coupling reaction and also as an electrocatalyst for the oxidation of cysteine. 相似文献
83.
84.
Subhasis Mallick Biplab K. Bera Parnajyoti Karmakar Subala Mondal Arup Mandal Alak K. Ghosh 《Journal of solution chemistry》2011,40(3):532-544
The interaction of di-μ-hydroxobis(bipyridyl)dipalladium(II) with the selected bio-relevant ligands: thioglycolic acid (HL1), glutathione(HL2) and DL-penicillamine(HL3) has been studied spectrophotometrically in aqueous medium as a function of complex and ligand concentrations, pH, and temperature
at constant ionic strength. Two consecutive reaction steps are observed: the first step is dependent on the incoming ligand
concentration and the second step which is independent, is assigned to ring closure. The activation parameters, conductivity
data and IR data obtained also support the proposed mechanism. 相似文献
85.
Rune F. Einrem Dr. Kevin J. Gagnon Dr. Abraham B. Alemayehu Prof. Dr. Abhik Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(2):517-520
With the exception of a single accidental synthesis, rhenium corroles are unknown, but of great interest as catalysts and potential radiopharmaceuticals. Oxidative metalation of meso‐triarylcorroles with [Re2(CO)10] in refluxing decalin has provided a facile and relatively high‐yielding route to rhenium(V)–oxo corroles. The complexes synthesized could all be fully characterized by single‐crystal X‐ray structure analyses. 相似文献
86.
The present study deals with the cylindrically symmetric inhomogeneous cosmological models for perfect fluid distribution with electro-magnetic field in Lyra geometry. Lie group analysis has been used to identify the generators (symmetries) that leave the given system of partial differential equations (field equations) invariant. With the help of canonical variables associated with these generators, the assigned system of partial differential equations is reduced to an ordinary differential equations whose simple solutions provide nontrivial solutions of the original system. They obtained a new class of invariant (similarity) solutions by considering the potentials of metric and displacement field are functions of coordinates t and x. The physical behavior of the derived models are also discussed. 相似文献
87.
Dr. Abraham B. Alemayehu Dr. Kevin J. Gagnon Prof. Dr. James Terner Prof. Dr. Abhik Ghosh 《Angewandte Chemie (International ed. in English)》2014,53(52):14411-14414
Heavy‐element corroles are of great interest as optical sensors, near‐IR dyes, phosphors, organic light‐emitting diodes, and anticancer compounds. Insertion of 5d metals into corroles, however, is often a difficult and unpredictable process. Against this backdrop, oxidative metalation of meso triarylcorroles with [Os3(CO)12]/NaN3 in refluxing 1:2 diethylene glycol monomethyl ether/glycol has provided a convenient and relatively high‐yielding route to nitridoosmium(VI) corroles, three of which could be characterized with single‐crystal X‐ray structure analysis. 相似文献
88.
A cosmological model has been constructed with Gauss–Bonnet-scalar interaction, where the Universe starts with exponential expansion but encounters infinite deceleration, q→∞ and infinite equation of state parameter, w→∞. During evolution it subsequently passes through the stiff fluid era, q=2, w=1, the radiation dominated era, q=1, w=1/3 and the matter dominated era, q=1/2, w=0. Finally, deceleration halts, q=0, w=−1/3, and it then encounters a transition to the accelerating phase. Asymptotically the Universe reaches yet another inflationary phase q→−1, w→−1. Such evolution is independent of the form of the potential and the sign of the kinetic energy term, i.e., even a non-canonical kinetic energy is unable to phantomize (w<−1) the model. 相似文献
89.
DFT calculations on the spin-crossover complex Fe(salen)(NO) provide a striking illustration of the comparative performance of different exchange-correlation functionals vis-à-vis the issue of transition metal spin state energetics. Thus, although the "classic" pure functionals PW91 and BLYP favor the S = 1/2 state by about 10 kcal/mol, relative to the S = 3/2 state, the hybrid functional B3LYP favors the latter state by nearly the same margin. In contrast, the newer pure functionals OLYP and OPBE, based on the OPTX exchange functional, as well as the B3LYP* hybrid functional (which has 15% Hartree-Fock exchange, compared with 20% for B3LYP) predict nearly isoenergetic S = 1/2 and 3/2 states, as required for a spin-crossover complex. Intriguingly, the OLYP and B3LYP* spin density profiles for the S = 1/2 state of Fe(salen)(NO) are substantially dissimilar. 相似文献
90.
Rough crack fronts in a sheet of paper, obtained during a creep experiment, do not follow true scaling laws. Local roughness exponents are estimated using the first order cumulant, a quantity recently introduced in the turbulence literature [J. Delour, J. F. Muzy, and A. Arneodo, Eur. Phys. J. B 23, 243 (2001)10.1007/s100510170074]. Using a large data set (102 fronts), we find a significant difference in local roughness between the slow (subcritical) and the fast growth regime. 相似文献