Cobalt-catalyzed stereoselective iodosulfonylation and diiodination of alkynes via oxidation of potassium iodide in air

Cobalt-catalyzed iodosulfonylation of alkynes can be achieved using sodium sulfinates in the presence of KI. This procedure produces numerous stereoselective (E)-β-iodoalkenyl sulfones with good yields and suppresses the formation of diiodoalkenes. Furthermore, when this reaction is performed in the absence of sodium sulfinates, the expected (E)-diiodoalkenes are obtained.     

Efficient dealkylation of aryl alkyl ethers catalyzed by Cu2O

An efficient protocol for dealkylation of aryl alkyl ethers under the catalysis of inexpensive and easily reusable Cu₂O has been described. The phenol products were obtained in high yields, and a range of functional groups were well tolerated. The choice of solvent is critical to the catalysis, and CH₃OH proved to be the optimal choice. Mechanistic investigations showed that this reaction possibly proceeds via a single-electron transfer (SET) process.     

Fe-based metal-organic frameworks for the synthesis of N-arylsulfonamides via the reactions of sodium arylsulfinates or arylsulfonyl chlorides with nitroarenes in water

A newly developed chemoselective reaction of sodium arylsulfinates or arylsulfonyl chlorides with nitroarenes has been disclosed. The chemistry, in which non-toxic water and recyclable iron-based metal-organic frameworks are employed as the solvent and catalyst, respectively, provides an efficient approach for the generation of N-arylsulfonamides, which are widely present in biologically active compounds and drugs, rendering this methodology attractive to both synthetic and medicinal chemistry.     

Structure of sodium perchlorate·diethylene glycol

The crystal structure of the 2:1 sodium perchlorate · diethylene glycol complex has been determined by single crystal X-ray diffraction. It crystallizes in space group P2₁2₁2 with a = 7.853(3), b = 7.900(2), c = 10.120(2) Å and Z = 2. Both the sodium ion and the diethylene glycol molecule are disordered, and were modeled with partial site occupancy factors. One sodium position is 7-coordinate and the other is 8-coordinate. The sodium perchlorate ions pack in layers parallel to [100] and [010], with the glycol molecules in channels between layers.     

A structural study of the perovskite series Na0.75Ln0.25Ti0.5Nb0.5O3

The ternary stoichiometric perovskite compounds, Na_0.75Ln_0.25Ti_0.5Nb_0.5O₃ (Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm) are intermediate members of the NaNbO₃-Na_0.5Ln_0.5TiO₃ solid solution series. The compounds were synthesized by standard ceramic methods at 1300 °C followed by annealing at 800 °C and quenching to ambient conditions. Rietveld analysis of the powder X-ray diffraction patterns shows that the compounds with Ln ranging from Pr to Tm adopt the orthorhombic space group Pbnm (a≈b≈√2a_p; c≈2a_p; Z=4) and the GdFeO₃ structure. In contrast, Na_0.75La_0.25Ti_0.5Nb_0.5O₃ adopts the orthorhombic space group Cmcm (a≈b≈c≈2a_p; Z=4). All cations located at the A- and B-sites are disordered in these compounds. The unit cell parameters and cell volumes of the compounds decrease regularly with increasing atomic number of the Ln cation. The Pbnm compounds with Ln from Sm to Tm have A-site cations in eight-fold coordination. A-site cations in the Pr and Nd compounds are considered to be in ten-fold coordination. Analysis of the crystal chemistry of the Pbnm compounds shows that B-site cations enter the second coordination sphere of the A-site cations for compounds with Ln from Tb to Tm as the A-B intercation distances are less than the maximum A-^IIO(2) bond lengths. The [111] tilt angles of the (Ti,Nb)O₆ polyhedra in the Pbnm compounds increase with increasing atomic number from 11.1° to 15.8° and are less than those observed in lanthanide orthoferrite and orthoscandate perovskites. These data are considered as relevant to the sequestration of lanthanide fission products in perovskite and the structure of lanthanide-bearing perovskite-structured minerals.     

Convenient route to dialkyl diselenides from alkyl tosylates. Synthesis of di(cis-myrtanyl) diselenide

A one-step method for the synthesis of dialkyl diselenides, by reaction of alkyl tosylates with sodium diselenide is described. Three variants of the synthesis, using as an example the preparation of optically active di(cis-myrtanyl) diselenide, are compared.     

示波极谱-四苯硼钠法的应用

示波极谱－四苯硼钠法是以示波极谱图形的突变来确定终点，其终点直观，不受溶液的颜色，沉淀，赋形剂的影响，可将重量分析，非水滴定，萃取－光度分析变为示波滴定分析，具有准，快，简，省的特点，有广泛的应用前景.     

TsCl-promoted sulfonylation of quinoline N-oxides with sodium sulfinates in water

An eco-friendly protocol for the synthesis of various 2-sulfonyl quinolines/pyridines through sulfonylation of heteroaromatic N-oxides with sodium sulfinates in water under metal-and oxidant-free conditions has been developed. The high reaction efficiency, operational simplicity, short reaction time, air-and moisture-insensitive conditions and remarkable functional group compatibility make the developed protocol very attractive for the preparation of 2-sulfonyl N-heteroaromatic compounds.     

丙醇-氯化钠-水体系萃取铑(Ⅲ)-氯化亚锡-2-巯基苯并噻唑络合物的研究与应用

研究了丙醇－氯化钠双水相体系萃取铑（Ⅲ）－氯化亚锡－2－巯基苯并噻唑（MBT）络合物的萃取行为及在丙醇萃取相中的光度性质；实验表明，在HCl介质中，铑（Ⅲ）的萃取率是99％，方法可从Fe、Al、Pb、Zn、Ca等常见金属基体中分离铑（Ⅲ），并建立了双水相体系萃取分光光度法测定微量铑（Ⅲ）的新方法。     

Effect of the Phase of Titanium Oxide on Metal-Support Interaction

The metal-support interaction in the system of platinum supported on titanium oxides of different crystalline structures was investigated. Titanium oxide powders used as supports were prepared by neutralization of TiOCl₂-analogue solution with either NaOH or NH₃ base at varied pH. Pt was introduced onto the supports by impregnation. The phenomenon of strong metal-support interaction (SMSI) was determined by the suppression of chemisorption of H₂ over samples reduced at 773 K, in comparison with the behavior of samples reduced at 473 K. The loss of adsorption capacity was proved not due to metal sintering by examining the recovery of adsorption capacity after reduction, reoxidation and reduction cycle, accompanied with examination of the size of Pt particle with an x-ray diffractiometer and a transmission-electron microscope. The results showed that SMSI phenomenon was common to Pt supported on titanium oxides of all the varied crystalline structures. However, the chemisorption capacity of Pt reduced at 473 K varied greatly with the sodium content in the supports, which in turns affects the crystalline structure of titanium oxide. These results are attributed mainly to electronic effect endowed by the support.