Mechanistic study of the addition reaction of TeCl4 to alkynes: Participation of TeCl3 centered-radical

The mechanism of the addition reaction of TeCl₄ to alkynes was indirectly established by the detection of TeCl₃ centered radicals using EPR spin trapping, ESI-MS and ESI-MS/MS characterization.     

Can the electron magnetic resonance (EMR) techniques measure the crystal (ligand) field parameters?

In this paper, the question posed in the title is critically examined on the basis of the available literature evidence implying the positive answer. The distinction between, on the one hand, the actual crystal field (CF) or equivalently ligand field (LF) related quantities and, on the other hand, the actual zero-field splitting (ZFS) or equivalently fine structure (FS) quantities, is elucidated. The origin and possible roots of the incorrect terminology consisting in mixing up the two physically distinct quantities at different levels are examined. Aspects concerning Hamiltonians, parameters, energy level splitting, and nature of the operators involved are taken into account. Problems with the various notations for the operators and parameters used in the electron magnetic resonance (EMR) area are also identified and reviewed. A large number of cases of incorrect terminology and other inconsistencies identified in the course of a comprehensive literature survey are analyzed and systematically classified. Implications of the confusion in question, which go beyond the simple semantic issues, are discussed. The results of the survey reveal that the two most serious categories of this confusion lead to misinterpretation of the experimental EMR data. Several examples of serious misinterpretations found in the books, reviews, and original papers are discussed. The incorrect terminology contributes also to misleading keyword classifications of papers in journals as well as references in scientific literature databases. Thus, the database searches may produce unreliable outcomes. Examples of such outcomes are also shown. It is concluded that, in order to prevent further proliferation of the incorrect terminology and thus to increase reliability of the published EMR data, a concerted effort within the EMR community is indispensable. Various ways in this regard at the international level are suggested.     

Ni~(2+):CsMgCl_3的光学吸收谱和EPR的研究

应用三角晶场中d2 (d8)电子组态包括静电相互作用和自旋 轨道耦合作用的强场能量矩阵 ,采用完全对角化方法 ,精确地计算了具有D3d 对称的Ni2 + :CsMgCl3 的光学吸收谱和EPR谱。理论结果与实验值符合得很好。     

Synthesis and characterization of new meso -substituted unsymmetrical metalloporphyrins

The synthesis and characterization of new meso-substituted unsymmetrical metalloporphyrins has been described. A new modified Adler method was used for the synthesis of two unsymmetrical porphyrins. Reactions of these unsymmetrical porphyrins with metal acetates afforded the corresponding metalloporphyrins in high yields with excellent purity. These porphyrins and their metal derivatives were characterized by spectroscopic methods. However, the copper complexes were further studied by ESR spectra and zinc complex by fluorescence spectrum.     

Infrared stealth and anticorrosion performances of organically modified silicate‐NiZn ferrite/polyaniline hybrid coatings

Hybrid coatings based on organically modified silicate‐Ni_0.5Zn_0.5Fe₂O₄/polyaniline were synthesized through a sol–gel technique with different NiZn ferrite/polyaniline weight ratio (1/1, 1/2, 1/5). These hybrid films were deposited via spin coating onto an aluminum alloy to improve the corrosion protection and to act as infrared stealth coatings. The effects induced by the NiZn ferrite/polyaniline hybrids on the chain dynamic, ferromagnetic behavior, infrared stealth, and anticorrosion performances of the coated samples were investigated. The rotating‐frame spin‐lattice relaxation times and scale of the spin‐diffusion path length indicated that the configuration of the hybrid films was highly cross‐linked and dense. The thermal extinction of the hybrid coatings increased with the increase in the polyaniline content. Potentio‐dynamic and salt‐spray analysis revealed that the hybrid films provided an exceptional barrier and corrosion protection in comparison with untreated aluminum alloy substrates. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 926–935, 2008