Photoluminescence of Seven-Coordinate Zirconium and Hafnium Complexes with 2,2′-Pyridylpyrrolide Ligands

Luminescent seven-coordinated zirconium and hafnium complexes bearing three mono-anionic 2,2′-pyridylpyrrolide ligands and one chloride were synthesized. Solid-state structures and the dynamic behaviors in solution were probed by X-ray crystallography and variable temperature ¹H NMR experiments, respectively. Absorption spectroscopy and time-dependent density functional theory (TD-DFT) calculations supported a hybrid of ligand-to-metal charge transfer (LMCT)/ligand-to-ligand charge transfer (LLCT) for the visible light absorption band. The complexes (^MePMP^Me)₃MCl (M=Zr, Hf, ^MePMP^Me=3,5-dimethyl-2-(2-pyridyl)pyrrolide) are emissive in solution at room temperature upon irradiation with visible light due to a combination of phosphorescence and fluorescence characterized by excited state lifetimes in the μs and low to sub-ns timescale, respectively. Electrochemical experiments revealed that the zirconium complex possesses a reversible redox event under highly reducing condition (−2.29 V vs. Fc^+/0).     

Ion Conductivity and Vibrational Spectra of LiNO3–KNO3 + Al2O3 Composites

Russian Journal of Electrochemistry - Composite solid electrolytes are synthesized on the basis of the eutectic nitrate mixture of 0.42LiNO3–0.58KNO3 doped by aluminum oxide nanosized powder....     

Pretransition Phenomena Near First-Order Phase Transitions in Ion-Molecular Crystals

Physics of the Solid State - Processes of molecular relaxation in Li2SO4, Na2SO4, and K2SO4 sulfates; Li2CO3, Na2CO3, and K2CO3 carbonates; NaClO4 and KClO4 perchlorates; and Ca(NO3)2, Sr(NO3)2,...     

Cooligomers of 1-hexene with dicyclopentadiene as synthetic components to petroleum oils

Cooligomers of 1-hexene with dicyclopentadiene were synthesized. Depending on the cooligomerization conditions, cooligomers with the molecular weight of 1000–4000, containing 10–20% dicyclopentadiene units, were obtained in a 76–92% yield. Aluminum chloride was used as the cooligomerization catalyst. The cooligomers synthesized were tested as components to M-6 and I-12A petroleum oils with the view of increasing their viscosity. The use of 25–40% cooligomer in these oils allows preparation of base oils with the viscosity index of 93–126. The resultant compounded oil possesses anticorrosive properties due to the presence of the dicyclopentadiene units in the cooligomer.     

Neutrino Oscillations: Entanglement,Energy-Momentum Conservation and QFT

We consider several subtle aspects of the theory of neutrino oscillations which have been under discussion recently. We show that the S-matrix formalism of quantum field theory can adequately describe neutrino oscillations if correct physics conditions are imposed. This includes space-time localization of the neutrino production and detection processes. Space-time diagrams are introduced, which characterize this localization and illustrate the coherence issues of neutrino oscillations. We discuss two approaches to calculations of the transition amplitudes, which allow different physics interpretations: (i) using configuration-space wave packets for the involved particles, which leads to approximate conservation laws for their mean energies and momenta; (ii) calculating first a plane-wave amplitude of the process, which exhibits exact energy-momentum conservation, and then convoluting it with the momentum-space wave packets of the involved particles. We show that these two approaches are equivalent. Kinematic entanglement (which is invoked to ensure exact energy-momentum conservation in neutrino oscillations) and subsequent disentanglement of the neutrinos and recoiling states are in fact irrelevant when the wave packets are considered. We demonstrate that the contribution of the recoil particle to the oscillation phase is negligible provided that the coherence conditions for neutrino production and detection are satisfied. Unlike in the previous situation, the phases of both neutrinos from Z ⁰ decay are important, leading to a realization of the Einstein-Podolsky-Rosen paradox.     

A new synthesis of methanoisoindoles

Russian Journal of Organic Chemistry -     

Palladium-containing composite nanomaterials based on polycaprolactam: Formation and structure

Novel Pd(0) nanocomposites using polycaprolactam as a reducing and stabilizing matrix are synthesized. Data on the nanoparticle formation mechanism in a polycaprolactam matrix under the conditions of changing pH of the medium and reagent concentration ratios are obtained. The nanocomposite structure is studied by electron and infrared spectroscopy, X-ray diffraction analysis, atomic force and transmission electron microscopy. The size of metal-containing particles in the composite composition and their size distribution are determined. The obtained nanocomposites can serve as heterogeneous catalysts.