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Том 470, № 1 (2016)
- Год: 2016
- Статей: 4
- URL: https://journals.rcsi.science/0012-5016/issue/view/9200
Physical Chemistry
The effect of hydrogen adsorption on the electronic structure of gold nanoparticles
Аннотация
It has been demonstrated that hydrogen adsorption has an effect on the electronic structure of gold nanoparticles. The physicochemical properties of separate gold nanoparticles have been studied under an ultrahigh vacuum scanning tunneling microscope. The structure and electronic structure of gold–hydrogen clusters were modeled by the quantum-chemical density functional theory method. Hydrogen adsorption onto gold nanoparticles 4–5 nm is size at room temperature was experimentally revealed, and the lower limit of 1.7 eV for the Au–H bond energy was determined. The interaction of hydrogen with gold leads to a considerable rearrangement of the electronic subsystem of nanoparticles. The experimentally observed effects were supported by quantum-chemical calculations. The rearrangement mechanism is related to strong correlations in the electronic subsystem.
125-128
Mesoscopic simulation of the synthesis of enzyme-like catalysts
Аннотация
A model based on the mesoscale simulation technique was developed for predicting the conditions for artificial enzyme formation from N-vinylcaprolactam (VCL) and N-vinylimidazole (NVI) by radical copolymerization of pre-synthesized poly-VCL blocks of different molecular weight with VCL and NVI comonomers. This synthetic procedure gives model copolymer chains. Upon a change in the solvent nature, these chains are able to form compact two-layer globular nanostructures with core–shell type morphology if the fraction of the first poly-VCL block is 25–38% of the total copolymer and the fraction of NVI monomers in the reaction mixture (in the concentration range considered) is maximum.
129-132
Simulation of highly emissive states based on ligand-to-metal charge transfer
Аннотация
Properties of the frontier orbitals of a d0-organometallic complex with promising photoluminescent and photosensor characteristics have been systematically studied by modern quantum-chemical methods. It has been demonstrated that the lowest electronically excited states are related to charge transfer from high-lying ligand-centered molecular orbitals to the predominantly metal-centered lowest unoccupied molecular orbital. Such an approach makes it possible to predict complexes with promising spectral-luminescent properties, including catalytic precursors of early transition metals.
133-136
Eutectoid decomposition of intermetallic CuZr
Аннотация
The eutectoid decomposition of intermetallic CuZr under isothermal and nonisothermal conditions was studied by differential scanning calorimetry, electrical resistivity measurements, X-ray diffraction analysis, optical microscopy, and dilatometry. The kinetic diagram of the eutectoid decomposition of intermetallic CuZr was determined for the first time. The rate of the eutectoid decomposition of the CuZr phase was found to be one to two orders of magnitude lower than that in many other copper-based systems. The kinetics of the eutectoid decomposition under isothermal conditions was investigated, and the kinetic parameters of the decomposition were determined (the activation energy Ea = 395 ± 24 kJ/mol and the Avrami constant n = 3.3 ± 0.1).
137-140