On the anomalous large-scale flows in the Universe

Recent combined analyses of the CMB and galaxy cluster data reveal unexpectedly large and anisotropic peculiar velocity fields at large scales. We study cosmic models with included vorticity, acceleration and total angular momentum of the Universe in order to understand the phenomenon. The Zel’dovich model is used to mimic the low redshift evolution of the angular momentum. Solving coupled evolution equations of the second order for density contrast in corrected Ellis–Bruni covariant and gauge-invariant formalism one can properly normalize and evaluate integrated Sachs–Wolfe effect and peculiar velocity field. The theoretical results compared to the observations favor a much larger matter content of the Universe than that of the concordance model. Large-scale flows appear anisotropic with dominant components placed in the plane perpendicular to the axis of vorticity (rotation). The integrated Sachs–Wolfe term has a negative contribution to the CMB fluctuations for the negative cosmological constant and it can explain the observed small power of the CMB TT spectrum at large scales. The rate of the expansion of the Universe may be substantially affected by the angular momentum if its magnitude is large enough.     

Identifying ferroresonance initiation for a range of initial conditions and parameters

The paper presents an experimental and numerical investigation carried out on a ferroresonant circuit in order to determine to what extent the initiation of ferroresonance depends on initial conditions and phase shift. The range of voltage source values at which the initiation of ferroresonance depends on initial conditions and phase shift is named as a possible ferroresonant range, and is determined numerically and experimentally.     

Base-catalyzed reactions of environmentally relevant N-chloro-piperidines. A quantum-chemical study

Electronic structure methods have been applied to calculate the gas and aqueous phase reaction energies for base-induced rearrangements of N-chloropiperidine, N-chloro-3-(hydroxymethyl)piperidine, and N-chloro-4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine. These derivatives have been selected as representative models for studying the chemical fate of environmentally relevant chloramines. The performance of different computational methods (MP2, MP4, QCISD, B3LYP and B2PLYP) for calculating the thermochemistry of rearrangement reactions was assessed. The latter method produces energies similar to those obtained at G3B3(+) level, which themselves have been tested against experimental results. Experimental energy barriers and enthalpies for ring inversion, nitrogen inversion and dehydrochlorination reactions in N-chloropiperidine have been accurately reproduced when solvent effects have been included. It was also found that the combined use of continuum solvation models (e.g. CPCM) and explicit consideration of a single water molecule is sufficient to properly describe the water-assisted rearrangement of N-chlorinated compounds in basic media. In the case of N-chloro-4-(4-fluorophenyl)-3-(hydroxymethyl)piperidine, which represents the chlorinated metabolite of the antidepressant paroxetine, several different reactions (intramolecular addition, substitution, and elimination reactions) have been investigated. Transition state structures for these processes have been located together with minimum energy structures of conceivable products. Imine 4A is predicted to be the most stable reaction product, closely followed by imine 4B and oxazinane 8, while formation of isoxazolidine 7 is much less favourable. Calculated reaction barriers in aqueous solution are quite similar for all four processes, the lowest barrier being predicted for the formation of imine 4A.     

Container Systems II: An Experimental Study of the High‐Pressure Intramolecular Cycloaddition of Tethered Furans and Anthracenes onto Norbornane Cyclobutene‐1,2‐diesters

A new class of container molecules is described and the first steps in producing protypes are reported. Central to the approach is the formation of polynorbornanes with cyclobutene‐1,2‐difurfuryl esters at the terminus or similar functionality at the bridgehead of a central norbornane subunit. The synthesis of the furfuryl starting materials is described as well as their anthracenyl counterparts. Conversion to the container systems involved the intermolecular linking of the furfuryl or anthracene by treatment with dimethyl acetylene dicarboxylate (DMAD) in a Diels–Alder (DA) protocol under thermal or high‐pressure (HP) conditions. In practice, no intermolecular linking occurred between the norbornane substrates and only products from DA 1:1‐addition with DMAD were produced. Intramolecular addition of one of the furfuryl units onto the cyclobutene π‐bond was detected under HP conditions, and this intermolecular product was capable of isolation and characterization by working at room temperature or below, but reverted to starting material above room temperature. When conducted in the presence of DMAD, a single 1:1‐adduct was obtained in which one furfuryl moiety was intramolecularly cyclized and the other present as the DMAD adduct; again this product underwent retro‐DA reaction at 40°C. Similar intermolecular cyclization was observed with the bis‐anthracenyl esters. The stereoselectivity of the intermolecular attack of the furfuryl diene with the dienophilic cyclobutene gave a single adduct by endo‐face attack in which the oxa‐bridge is endo‐positioned. Quantum chemical DFT calculations (B3LYP) predict that the formation of the endo‐isomer is kinetically favored and that relief of ring strain enhances the rate of retro‐Diels–Alder in the tethered system.     

Structure of Diels-Alder adduct of phenylated germole and 1,4-epoxy-1,4-dihydronaphthalene revisited

High pressure synthesis of Diels-Alder adduct of 1,1-dimetyl-2,3,4,5-tetraphenylgermole and 6,7-dibromo-1,4-epoxy-1,4-dihydronaphthalene is described. The X-ray crystallography analysis of the so obtained adduct indicated that the adduct has exo,endo-structure in agreement with our earlier proposal for the stereochemistry of the structurally related germa analogue, 11,11-dimethyl-9,10-epoxy-1,4-germa-1,2,3,4-tetraphenyl-1,4,4a,9,9a,10-hexahydroanthracene based on NMR analysis.