Polymerization of Methylene Dichloride and Sodium Tetrasulfide: Synthesis and Kinetic Studies

The kinetics of the condensation polymerization of a novel polysulfide polymer based on methylene dichloride and sodium tetrasulfide is studied. The results of the experiments indicated that the reaction order is two. The activation energy obtained from the Arrhenius plot is 1.879 kcal mol^?1, and the pre-exponential frequency factor is A = 27.11 min^?1 at temperature range of 40～60°C. The polymer is characterized by using Fourier transform-infrared and CHN analysis. Thermal properties were evaluated by differential scanning calorimetry. The TGA-DTA was used to find out the thermal stability of polymer. The solvent resistance of the polymer was investigated by the swelling method.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Ab Initio Study of Structures,Metallotropic 1,2-Shifts and Prototropic 1,2-Shifts of Cyclopentadienyl(trimethyl)silane, -germane and -stannane

Molecular structures, metallotropic and prototropic shifts of cyclopentadienyl(trimethyl)silane ( 1 ), cyclopentadienyl(trimethyl)germane ( 2 ), and cyclopentadienyl(trimethyl)stannane ( 3 ) were investigated using ab initio molecular orbital and the Becke, Lee, Yang, and Parr density functional (B3LYP) methods. The results show that the most stable structure of compounds 1-3 has the (CH 3 ) 3 M fragment in the allylic position. The energy barrier of metallotropic shifts in compound 1 is higher than in 2 , and in compound 2 higher than in 3 , in good agreement with experimental data. The cyclopentadienyl rings in compounds 1-3 are found to be planar but this result contradicts the reported experimental data.     

Synthesis,Crystal Structure,and Antibacterial Activity of Di-μ-chlorido-bis({2-[(4-methoxyphenyl)-iminomethyl]pyridine-κ2N,N'] Mercury(II)

Crystallography Reports - A coordination polymer [Hg(L)Cl2]n consisting of HgCl2 and Schiff base bidentate ligand (4-methoxyphenyl) pyridine-2yl methyleneamine (L) was prepared and structurally...