A. K. Buryak

Macrocyclic Complexes of Palladium(II) with Benzothiacrown Ethers: Synthesis, Characterization, and Structure of cis and trans Isomers

A series of palladium(II) complexes with nitro- and formylbenzothiacrown-ether derivatives was synthesized. The spatial structure of the complexes was studied by NMR, X-ray diffraction analysis, and quantum chemical calculations (density functional theory). The cavity size and the ligand denticity were found to be crucial factors determining the geometric configuration of the thiacrown-ether complexes. Palladium(II) complexes with benzodithia-12(18)-crown-4(6) ethers were demonstrated to have a cis-configured S(2)PdY(2) fragment (Y = Cl, OAc). In the case of Pd(II) and benzodithia-21-crown-7 ethers, only complexes with a trans configuration of the S(2)PdY(2) fragment form. In the case of Pd(II) and nitrobenzomonothia-15-crown-5 ether, only 2(ligand):1(Pd) complex with trans configuration of the core fragment forms.

Chromatography: Method of investigation of surface chemistry and interface processes

This paper discusses application of gas and liquid chromatography to studies of surface chemistry and various materials. Examples of studying adsorption processes from gas and liquid media with application of the chromatography technique are given. It is shown that the information on the structure of the material obtained using the chromatography technique allows predicting the regularities of chromatographic retention for molecules of different structures and various sorbents. The chromatography technique is frequently used in studies of nanomaterials and stable nanoparticles. It is shown that the chemical properties of surfaces modified by nanoparticles can be advantageously used in gas and liquid chromatography techniques. Much attention is given to molecular statistical calculations of adsorption on carbon sorbents in gas and liquid chromatography. The possibilities of the technique regarding prediction of retention of various sorbates and specification of structural parameters of molecules are demonstrated. Methodological and preparative aspects of a new area, micellar chromatography of nanoparticles, are considered. Options of liquid chromatography for separation, including preparative separation, identification, and classification, are shown.

Palladium-catalyzed amination of isomeric dihalobenzenes with 1- and 2-aminoadamantanes

Palladium-catalyzed amination of isomeric bromochloro- and dibromobenzenes with 1- and 2-aminoadamantanes was studied. The best yields of the corresponding monoamination products were obtained in the reactions of 2-aminoadamantane with bromochlorobenzenes. The arylation of 1-aminoadamantane was successful in the presence of donor phosphine ligand. The amination of o- and m-dibromobenzenes was strongly complicated by formation of diamination products. Conditions ensuring predominant formation of the latter were found. The arylation of 2-aminoadamantane was accompanied by oxidation of the initial amine and reduction of aryl halide.

Structural-functional characteristics of a new bioregulator isolated from bovine pigmented epithelium tissue

A new bioregulator operating in ultralow doses corresponding to 10−17 mg/ml has been isolated from tissue of pigmented epithelium of bovine eyes. It has been established that the functional basis of this bioregulator is a complex of a low molecular weight regulatory peptide (4372 Da) and a modulator consisting of a mixture of proteins with molecular weights of 14.980–66.283 kDa. It has been shown that the regulatory peptide is responsible for membranotropic activity of the bioregulator, and the modulator proteins are responsible for biological action in ultralow doses. The data demonstrate an interrelation between nanocondition of the bioregulator and its ability to show activity in ultralow doses.

Experimental Modeling of Transport and Deposition of Hydrocarbon Radicals on ITER-FEAT Cold Trap

Abstract The surface loss probability, β , of methyl (CH 3 ) radicals and atomic (H) hydrogen on a growing film surface was measured at lowered temperatures. The loss of reactive species was investigated by analysis of the deposition profiles along a quartz tube reactor directly coupled with a methane RF discharge (so-called ‘stream’ technique). The experiments were performed using special external containers with dry ice (∼200 K) and liquid nitrogen (77 K). It has been found that β (CH 3 ) on the growing film surfaces increases from 1.6×10 −4 at 300 K to 6.2×10 −4 at 200 K. Based on the data analysis, β for H can be deduced. The β (H) values were 3×10 −4 , 1×10 −3 and at least 10 −2 at 300 K, ∼200 K and 77 K, respectively. Film deposition from hydrocarbon radicals generated in a magnetron discharge is studied at temperatures from 300 K down to 120 K. Transition from formation of film-like to drop-like deposit is observed with cooling the substrate from 220 to 120 K. The application of the results to the understanding of transport and deposition of neutral reactive species on ITER-FEAT cold trap have been given.

Arylation of Adamantanamines: III.* Palladium-Catalyzed Arylation of Adamantane-1,3-diyldimethanamine and 2,2'-(Adamantane-1,3-diyl)diethanamine

Palladium-catalyzed arylation of adamantane-1,3-diyldimethanamine and 2,2′-(adamantane-1,3-diyl) diethanamine with isomeric bromochloro- and dibromobenzenes was studied. The yields of N,N′-diarylation products depend on the initial diamine and dihalobenzene structure. Side reactions were revealed, which reduced the yield of the target products. The arylation of 2,2′-(adamantane-1,3-diyl)diethanamine gives the corresponding N,N′-diaryl derivatives with better yield. The possibility for synthesizing unsymmetrical N,N′-diaryl derivatives of 2,2′-(adamantane-1,3-diyl)diethanamine was demonstrated.

Physicochemical fundamentals of mass spectrometry with matrix/surface-assisted laser desorption/ionization for studies of inhibitors

The review explains the fundamentals of the methods of mass spectrometry with matrix assisted laser desorption/ionization (MALDI) and mass spectrometry with surface-assisted laser desorption/ionization (SALDI). Basics of these mass spectrometric techniques and regularities of applications of matrixes of various types are discussed. Examples of using the MALDI and SALDI techniques are presented for obtaining spectra of low-molecular compounds and compounds with a high molecular mass in connection with studies of corrosion inhibitors.

MALDI/SELDI mass-spectrometric surface investigation of AMg-6 and Ad-0 materials

Matrix-assisted and surface-enhanced laser desorption/ionization mass-spectrometry is carried out in order to investigate the surfaces of structural materials using marker substances. The method is shown to provide estimates of the surface heterogeneity and can be used for the quantitative comparison of the heterogeneity of different surfaces. In the domains where homogeneity is distorted, a larger amount of the marker substance is observed. Properly selected marker substances and the high sensitivity of mass-spectrometry make it possible to use the method for the express estimation of the surface heterogeneity.

Effect of surface chemistry of carbon sorbents on high-performance liquid chromatography and mass-spectrometric analysis of amino acids

The work shows a complex approach to analyzing amino acids using carbon sorbents with different surface areas, including molecular-statistical calculations, high-performance liquid chromatography, and mass spectrometry with matrix-activated and surface-activated laser desorption/ionization (MALDI, SALDI). An analysis of the thermodynamic adsorption characteristics (TACs) of a series of proteinogenic amino acids and their isomers on graphitized thermal carbon black (GTCB) is carried out. A satisfactory correlation is established between experimental characteristics of amino-acid retention on the Hypercarb carbon sorbent and TACs of these particles calculated using the molecular statistics method. It is found in the identification of amino acids using the MALDI method in the chromato-mass-spectrometric modification in the off-line mode that the application of carbon sorbents as a support results in an increase in the intensity of the registered protonated molecular ions and adducts with alkali cations compared to a conventional experimental technique on a stainless-steel surface.

Laser desorption/ionization mass-spectrometric study of surface chemistry of Ad-0 and AMg-6 alloys

Ad-0 and AMg-6 alloy surfaces are studied using matrix-enhanced laser desorption/ionization mass spectrometry. Inorganic salts, namely, nickel chloride and silver halides, which form cluster ions at the ionization, were taken as test molecules. Mass spectra revealed a principal difference between the desorption/ionization mechanisms depending on the surface kind and its prehistory. Qualitative and quantitative investigation of the mass spectra led to certain suppositions about the photoionization mechanisms of the cluster structures of inorganic nickel and silver salts. It is shown that, on the studied surfaces, parameters that characterize the surface chemistry can be estimated based on the mass spectra of the salts.