Functionalization of the pyridazin-3(2H)-one ring via palladium-catalysed aminocarbonylation

5-Iodo- and 4,5-dibromo-2-methylpyridazin-3(2H)-ones were aminocarbonylated in the presence of various amines including amino acid methyl esters in a palladium-catalysed reaction. The iodo derivative afforded the corresponding amides with complete conversion and high isolated yields. The dibromo derivative has shown unexpectedly high reactivity in this reaction, resulting in 4,5-dicarboxamides using primary amines as N-nucleophiles. Monoaminocarbonylation has not been observed, i.e., neither 4-bromo-5-carboxamide nor 4-carboxamido-5-bromo derivatives have been formed. However, the use of secondary amines such as piperidine and morpholine resulted in the formations of mixtures of amino-substituted bromopyridazinones. That is, no carbon monoxide insertion took place in these cases. Some mechanistic details of the formation of aminocarbonylation and amination products are also discussed.     

Causes of the double maximum conductivity of nanocomposite polymer electrolytes for lithium power sources

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First-principles prediction and partial characterization of the vibrational states of water up to dissociation

A new, accurate, global, mass-independent, first-principles potential energy surface (PES) is presented for the ground electronic state of the water molecule. The PES is based on 2200 energy points computed at the all-electron aug-cc-pCV6Z IC-MRCI(8,2) level of electronic structure theory and includes the relativistic one-electron mass-velocity and Darwin corrections. For H₂¹⁶O, the PES has a dissociation energy of D₀ = 41 109 cm⁻¹ and supports 1150 vibrational energy levels up to 41 083 cm⁻¹. The deviation between the computed and the experimentally measured energy levels is below 15 cm⁻¹ for all the states with energies less than 39 000 cm⁻¹. Characterization of approximate vibrational quantum numbers is performed using several techniques: energy decomposition, wave function plots, normal mode distribution, expectation values of the squares of internal coordinates, and perturbing the bending part of the PES. Vibrational normal mode labels, though often not physically meaningful, have been assigned to all the states below 26 500 cm⁻¹ and to many more above it, including some highly excited stretching states all the way to dissociation. Issues to do with calculating vibrational band intensities for the higher-lying states are discussed.     

Aeroacoustics research in Europe: The CEAS-ASC report on 2010 highlights

The Council of European Aerospace Societies (CEAS) Aeroacoustics Specialists Committee (ASC) supports and promotes the interests of the scientific and industrial aeroacoustics community on an European scale and European aeronautics activities internationally. In this context, “aeroacoustics” encompasses all aerospace acoustics and related areas. Each year the committee highlights some of the research and development projects in Europe.This paper is a report on highlights of aeroacoustics research in Europe in 2010, compiled from information provided to the ASC of the CEAS.At the end of 2010, project X-NOISE EV of the Seventh Framework Programme of the European Commission has been launched as a continuation of the X-Noise series, with objectives of reducing aircraft noise and reaching the goal set by the ACARE 2020 Vision.Some contributions submitted to the editor summarizes selected findings from European projects launched before or concluded in 2010, while other articles cover issues supported by national associations or by industries. Furthermore, a concise summary of the workshop on “Aeroacoustics of High-Speed Aircraft Propellers and Open Rotors” held in Warsaw in October is included in this report.Enquiries concerning all contributions should be addressed to the authors who are given at the end of each subsection.     

Microwave-assisted selective protection of glutaraldehyde and its symmetrical derivatives as monoacetals and -thioacetals

Six monoprotected acetals and -thioacetals of glutaradehyde and its symmetrical dimethyl derivatives were synthesized. Microwave-assisted heating proved to be a substantially more selective method for monoprotection than conventional heating. All reactions were efficient and only traces of diprotected material were formed.     

Hexane dehydrogenation to hexenes: a general indicator for deactivation of Pt catalysts in “skeletal” reactions

The comparative evaluation of dehydrogenation yields and selectivities of skeletal reactions from n-hexane reactions on monofunctional Pt catalysts is a good universal indicator of catalyst deactivation, independently of the presence and the nature of the support. Four regions could be defined with increasing carbon accumulation, causing "beneficial", "selective", "nonselective" and "severe" deactivation.     

Resonant non-linear waves—III. Elastic continuum with quadratic non-linearity

The paper derives the relevant non-linear integro-differential evolution equation by the method due to Collins expanding on a procedure by Keller. The quadratically non-linear case is not a trivial variation over the cubically non-linear case that was presented in preceding papers. As expected a different scaling and ordering of terms is needed and the first order perturbation solution provides no information on resonance. Nevertheless, although obtained by much longer calculations, the final equation for the present case is of identical form, with differences only in numerical coefficients, with the cubic case that was presented and solved earlier.     

Solvent Relaxation in Phospholipid Bilayers: Principles and Recent Applications

Although there exist a number of methods, such as NMR, X-ray, e.g., which explore the hydration of phospholipid bilayers, the solvent relaxation (SR) method has the advantage of simple instrumentation, easy data treatment and possibility of measuring fully hydrated samples. The main information gained from SR by the analysis of recorded “time-resolved emission spectra” (TRES) is micro-viscosity and micro-polarity of the dye microenvironment. Based on these parameters, one can draw conclusions about water structure in the bilayer. In this review, we focus on physical background of this method, on all the procedures that are needed in order to obtain relevant parameters, and on the requirements on the fluorescence dyes. Furthermore, a few recent applications (the effect of curvature, binding of antibacterial peptides and phase transition) illustrating the versatility of this method are mentioned. Moreover, limitations and potential problems are discussed.     

Intranasal irradiation with the xenon chloride ultraviolet B laser improves allergic rhinitis

We earlier reported that the 308 nm xenon chloride (XeCl) ultraviolet B (UVB) laser is highly effective for the treatment of inflammatory skin diseases. Since UVB irradiation has been shown to exert both local and systemic immunosuppression, we investigated the clinical efficacy of UVB irradiation in allergic rhinitis. In an open study, groups of patients with severe allergic rhinitis received intranasal irradiation with a 308 nm XeCl UVB excimer laser for two weeks. In the low-dose group (n=10), treatment was given twice weekly, starting with 0.25x the individual minimal erythema dose (MED), whereas patients in the medium-dose group (n=8) were treated four times weekly, starting with 0.4x MED. In each group, the dosage was gradually increased. Evaluation was based on the symptom scores. The effect of the XeCl laser on the skin prick test reaction was also studied. In the low-dose group, seven patients completed the study, and there was no improvement in the nasal symptoms. In the medium-dose group, the XeCl UVB irradiation significantly inhibited the rhinorrhoea, the sneezing, the nasal obstruction and the total nasal score (p<0.05). The XeCl UVB excimer laser also inhibited the allergen-induced skin prick test in a dose-dependent manner. These results suggest that the XeCl UVB excimer laser might serve as a new therapeutic tool in the treatment of allergic rhinitis.