A. Tolstogouzov

Magnetically recyclable magnetite–palladium (Nanocat-Fe–Pd) nanocatalyst for the Buchwald–Hartwig reaction

The immobilization of Pd on the magnetite surface afforded Nanocat-Fe–Pd using inexpensive precursors and its catalytic role in the Buchwald–Hartwig reaction for arylation of amines and amides was investigated; C–N bond formation was achieved in moderate to excellent yields and the catalyst could be separated and recycled up to five cycles by magnetic decantation without a significant loss in yield.

Nano-MgO–ZrO2 mixed metal oxides: characterization by SIMS and application in the reduction of carbonyl compounds and in multicomponent reactions

A nano-sized Magnesia–Zirconia (nano-MgO–ZrO2) catalyst was prepared by a simple ultradilution co-precipitation method and by using inexpensive precursors. The nano-MgO–ZrO2 was extensively characterized by SIMS together with other analytical techniques such as X-ray diffraction (XRD) and transmission electron microscopy (TEM). The nano-MgO–ZrO2 catalyst proved to be very efficient for the reduction of carbonyl compounds and multicomponent reactions under mild reaction conditions. The recyclability and reusability of the nano-MgO–ZrO2 catalyst has been tested.

Identification of human calculi with time‐of‐flight secondary ion mass spectrometry

Time-of-flight secondary ion mass spectrometry was used to study four human calculi and to compare the results with those from twelve commercially available urinary calculi minerals including three organic compounds (L-cystine, uric acid and sodium urate). Phase identification of calcium phosphate compounds was carried out by considering the relative ion abundances of [Ca(2)O](+) and [CaPO(2)](+). Deprotonated [M-H](-) and protonated [M+H](+) uric acid were detected and used for component recognition in pure uric acid and in the mixed samples of struvite, calcium oxalate and uric acid. Iodine related to the medical history of a patient was also detected.

TOF-SIMS study of cystine and cholesterol stones

Two different human stones, cystine and cholesterol from the kidney and gall bladder, were examined by time-of-flight secondary ion mass spectrometry using Ga(+) primary ions as bombarding particles. The mass spectra of kidney stone were compared with those measured for the standard compounds, cystine and cysteine. Similar spectra were obtained for the stone and cystine. The most important identification was based on the existence of the protonated molecules [M + H](+) and deprotonated molecules [M-H](-). The presence of cystine salt was also revealed in the stone through the sodiated cystine [M + Na](+) and the associated fragments, which might be due to the patient treatment history. In the gallstone, the deprotonated molecules [M-H](+) of cholesterol along with relatively intense characteristic fragments [M-OH](+) were detected.

Evaporation of ionic liquids at atmospheric pressure: Study by ion mobility spectrometry

A conventional ion mobility spectrometry (IMS) was used to study atmospheric pressure evaporation of seven pure imidazolium and pyrrolidinium ionic liquids (ILs) with [Tf(2)N], [PF(6)], [BF(4)] and [fap] anions. The positive drift time spectra of the as-received samples measured at 220°C exhibited close similarity; the peak at reduced mobility K(0)=1.99 cm(2)V(-1)s(-1) was a dominant spectral pattern of imidazolium-based ILs. With an assumption that ILs vapor consists mainly of neutral ion pairs, which generate the parent cations in the reactant section of the detector, and using the reference data on the electrical mobility of ILs cations and clusters, this peak was attributed to the parent cation [emim]. Despite visible change in color of the majority of ILs after the heating at 220°C for 5h, essential distinctions between spectra of the as-received and heated samples were not observed. In negative mode, pronounced peaks were registered only for ILs with [fap] anion.

Ion-beam sources based on room-temperature ionic liquids for aerospace applications, nanotechnology, and microprobe analysis (review)

An analytical review of the stages of development and state-of-the-art of ion-beam sources, which are based on room-temperature ionic liquids for aerospace and ion-beam technologies, is presented. The properties of ionic liquids—new ion-conducting materials (“liquid plasma or plasma in a bottle”)—are discussed. The design, operating conditions, and technology of manufacturing pointlike, capillary, matrix, and linear ion sources with ionic liquids are described in detail. The main fields of their application, including electrostatic rocket engines (microthrusters) for CubeSat-format satellites and systems with focused ion beams for technological processing of materials and structures in the nanometer region and for microprobe investigations are analyzed.

Analysis of the conditions underlying the formation of emitted atomic ion fluxes in the nonlinear collision-cascade mode of the sputtering of metals

The ion-beam sputtering of metals carried out in the nonlinear collision-cascade mode, where the excitation level (average energy per atom) in the thermal-peak volume exceeds the critical ambient temperature, initiates quasi-thermal atom and atomic ion emissions. The energy spectrum of atomic particles is substantially shifted toward the low-energy region and does not correspond to a Maxwellian distribution. Correct description of quasi-thermal ion emission requires first of all knowledge of the conditions under which a sputtered particle flux is formed. The conditions leading to the formation of an atomic ion flux are analyzed for the case where metals are sputtered in the nonlinear collision-cascade mode.

Fabrication of nitrogen-containing coatings in reed switches by pulsed ion-plasma treatment

We focus on the detailed characterization of the coatings produced by pulsed ion-plasma treatment on contact surfaces of permalloy (iron-nickel) blades directly in nitrogen-filled reed switches. The measurements of electrical resistance, breakdown voltage and return factor of reed switches were carried out in situ prior to and after ion-plasma treatment, and the morphology and elemental (chemical) composition of the coatings were monitored ex situ by means of scanning electron microscopy and energy dispersive X-ray microanalysis. The main processes occurring on the contact surfaces in the course of ion-plasma treatment were discussed in the frame of anomalous glow and arc discharges theories by Mesyats. It was shown that ionplasma treatment allows fabrication of erosion- and corrosion-resistant nitrogenated iron-nickel coatings with the electrical resistance of 0.1 Ohm. In the optimal symmetrical mode with the processing time of ca. 7 min the nitrogen concentration in the coatings was estimated of 20 at %. Higher and lower nitrogen content and the presence of oxygen in the coatings showed negative influence on the electrical resistance, which determines the quality of reed switches. Prototype models of the reed switches with nitrogenated coatings successfully passed switchgear reliability tests and demonstrated the competitive capacity as regards the standard reed switches with electroplating coatings based on the noble metals.

On the possibility of using the nanosize effect of ion sputtering in the development of a high-current source of atomic and cluster ions of solid-state elements

The methods for improving the efficiency of processes whereby metals are sputtered in the form of atomic and cluster ions are analyzed. The obtained results can be used to develop a new generation of sputtering-type high-current sources capable of generating atomic and cluster ions of solid-state elements, which are intended for technological applications.

Study on sublimation of solid electrolyte (AgI)0.5-(AgPO3)0.5 with Knudsen effusion mass spectrometry

Knudsen high-temperature mass spectrometry was used to study the process of sublimation of a solid electrolyte (AgI)(0.5-)(AgPO(3))(0.5). Monoatomic iodine ions were found to be the dominant species in the electron ionization mass spectra below 600 degrees C. With an increase in temperature, the relative content of phosphorus oxide ions, mainly [PO](+) and [P(4)O(10)](+), increased. Under further heating, we observed silver iodide and iodine dimer ions together with phosphorus dimer and tetramer ions and clusters [IPO(2)](+), [IP(2)](+), [I(3)P](+). Using the experimental logarithmic dependencies of ion signal intensities versus the reciprocal absolute temperature of the effusion cell, the apparent sublimation enthalpies Delta(s)H of the ions giving the most intense signals were estimated.