σ,π-acetylido complexes via P---C bond cleavage of phosphinoacetylenes: X-ray structure of Fe2(CO)6(CCPh)(PPh2)

Solutions of Co^II salts of organic acids in primary amines absorb molecular oxygen rapidly and irreversibly forming μ-dioxygen—cobalt complexes. Thermolysis leads to a homopolar cleavage of the OO bond with subsequent radical reactions involving ligand amine. After thermolysis the capacity of oxygen uptake is reestablished (catalysis).     

Potentiometric studies of dithiooxamide with a sulphide-selective membrane electrode

The sulphide-selective electrode is applicable to the determination of dithiooxamide by titration with silver nitrate. The effect of the alkali content of the solutions on the reaction has been studied. The reaction products are silver sulphide, oxalic acid, and nitric acid. If the alkali concentration of the solution is lower than that equivalent to the acid formed during the titration, the amount of sulphide produced by hydrolysis decreases and the equilibrium potential is established more slowly.The determination is rapid and accurate in the presence of 1 M sodium hydroxide.     

A Novel Real-time Fluorescence Mutant-allele-specific Amplification Method for Rapid Single Nucleotide Polymorphism Analysis

Current methods for single nucleotide polymorphism (SNP) analysis are time-consuming and complicated. We aimed at development of one-step real-time fluorescence mutant-allele-specific amplification (MASA) method for rapid SNP analysis. The method is a marriage of two technologies: MASA primers for target DNA and a double-stranded DNA-selective fluorescent dye, SYBR Green I. Genotypes are separated according to the different threshold cycles of the wild-type and mutant primers. K-rar oncogene was used as a target to validate the feasibility of the method. The experimental results showed that the different genotypes can be clearly discriminated by the assay. The real-time fluorescence MASA method will have an enormous potential for fast and reliable SNP analysis due to its simplicity and low cost.     

Stochastic model of dissociation-recombination kinetics in micelles

The small number of reagents solubilized in a micelle prohibits the use of conventional reaction kinetics. In order to describe the kinetics of the reaction A + B ? AB proceeding in a micellar phase, a stochastic model is evaluated. The deviation of these results from those obtained by conventional kinetics may be as high as 20%.     

Bibliometric Analysis of the <Emphasis Type="Italic">Journal of Structural Chemistry</Emphasis>

Bibliometric analysis has been carried out for the Journal of Structural Chemistry (JSC) published since 1960 by the Siberian Branch of the Russian Academy of Sciences. All JSC publications which appeared between 1960 and 2002 have been chosen online from the Chemical Abstracts and Science Citation Index databases of the STN International net and analyzed according to topics, authors, affiliations, and other criteria. JSC authors and publications with the largest numbers of citations have been identified. The impact factor has been determined for JSC 2002.Original Russian Text Copyright © 2004 by V. M. Buznik, I. V. Zibareva, V. N. Piottukh-Peletskii, and N. I. Sorokin__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1142–1153, November–December, 2004.     

Spectroscopy of large molecules in inert gas clusters

Aromatic hydrocarbons provide nucleation centers for the formation of clusters of inert gases in high-flow supersonic beams. Large clusters of Ar, each containing a single tetracene (T) molecule, were prepared by supersonic expansion of the seeded gas at pressures p = 3000–13000 Torr and interrogated by laser-induced fluorescence spectroscopy Evidence is reported for homogeneous line broadening of large TAr_n clusters prepared at p? 8000 Torr.     

Reaction of η5-cyclopentadienylbis(triphenylphosphine)cobalt(I) with alkadiynes. Preparation and reactions of bicyclic cobalt metallocycles and a stable trimethylsilyl-substituted mono-complexed alkadiyne. Comments on the mechanism of cobalt-catalyzed alkyne cooligomerization

Reactions of η⁵-cyclopentadienylbis(triphenylphosphine)cobalt(I) (5) with several 2,n-alkadiynes (2) were investigated. Each of these reactions leads initially to a material in which one of the acetylene functional groups is π-coordinated to cobalt; this complex then undergoes conversion to a metallocycle. In cases where the two acetylene functions are connected by three- and four-carbon bridges (2b, 2c), metallocycles formed by intramolecular reaction of two acetylene functions in the same molecule may be isolated. In cases where the acetylene functions are joined by larger or smaller bridges, the reactions are more complex, and both inter- and intramolecular metallocycles are formed. Reactions of 5 with 1,8-bis(trimethylsilyl)-1,7-octadiyne (16) gives an isolable crystalline mono-acetylene complex (17), this material is stable in the solid state but undergoes conversion to metallocycle (18) in benzene solution. The relationship of these results to the mechanism of the CpCo(CO)₂-catalyzed benzocycloalkene synthesis is discussed; it is suggested that intramolecular metallocycles are intermediates in reactions leading to benzocyclopentanes and -cyclohexenes, but intermolecular metallocycles are probably involved in reactions leading to benzocyclobutenes.     

“化学在抗击新冠肺炎疫情中扮演的重要角色”专题教学

Considering COVID-19 epidemic prevention and control, education materials were excavated and refined, such as chemical disinfectants, typical drugs used in clinical treatment or trial and materials for preparation of medical protective equipment. We have carried out thematic teaching on "The important role of chemistry in the fight against COVID-19 epidemic", and integrated ideological and political education into the thematic teaching. Through thematic teaching, we can make students feel the charm of chemistry subject, stimulate students' interest in learning chemistry, fully mobilize students' learning enthusiasm and initiative, strengthen students' confidence and courage to overcome difficulties, cultivate the students' professional disciplines literacy and scientific literacy, activate students' love for the motherland, the people and the Communist Party of China.     

Chemistry of metal hydrides : XXI. Insertion of acetylenes into palladium hydrides

trans-Pd(NO₃)H(PCy₃)₂ (I) when treated with Et₄NCl forms the hydride trans-PdClH(PCy₃)₂ which in turn reacts with AgPF₆ in acetonitrile to give trans-[PdH(CH₃CN)(PCy₃)₂]PF₆ (III). Both I and III react smoothly with acetylenes containing one electron-withdrawing group to give alkenyl products. The geometry of the resulting alkenyl ligand implies that cis addition has occurred and that the hydridic hydrogen adds to the acetylenic carbon containing the electron-withdrawing group.Acetylenes containing two electron-withdrawing groups give mixtures from which both alkenyl and zerovalent acetylene compounds can sometimes be isolated. In the presence of proton sponge, monosubstituted acetylenes still give alkenyl products while those substituted with two electron-withdrawing groups give the zerovalent products in good yield. The relevance of these results to an understanding of the nature of the migratory insertion reaction is discussed.