The role of Sm ions in optical storage of SrS : Eu, Sm

The optical absorption spectra of infrared stimulable phosphor SrS: Eu, Srn in the saturated and bleached states of optical storage were investigated. The valence and number of Sm³⁺ ions were examined via the Sm³⁺ 4f-4f absorption in near-infrared region. It was found that the broad band absorption corresponding to the transition for electrons stimulated from the traps to the conduction band is decreased at the wavelengths of Sm³⁺ absorption lines. The dependence of optical storage on Sm concentration was measured. A new trapping mechanism in SrS:Eu,Sm was presented based on our experimental results and the role of Sm ions was identified     

Reductive Cyclodimerization of α, β‐ Unsaturated Ketones Promoted by AlCl3/Sm System: A Facile Synthesis of 2‐Aroyl‐1,3,4‐triaryl Cyclopentanol Derivatives

Promoted by AlCl₃/Sm bimetallic system, α, β‐unsaturated ketones underwent reductive cyclodimerization to afford cyclopentanol derivatives under mild conditions. The reaction is stereocontrolled and regioselective over the competitive carbon‐carbon double bond reduction.     

Tandem Michael imino–aldol reactions catalyzed by samarium diiodide

Samarium diiodide catalyzes a one-pot procedure allowing to perform sequentially the Michael addition of a ketene silyl acetal on a cyclic ,β-unsaturated ketone, followed by the addition of a glyoxylic or aromatic imine. The presence of a coordinating group on the imine increases the rate of the reaction.     

Synthesis and Crystal Structure of （1,3—^tBu2C5H3）2Sm（μ—Cl）2Li（THF）2

1　ＩＮＴＲＯＤＵＣＴＩＯＮＡｓａｔｙｐｅｏｆｉｍｐｏｒｔａｎｃｅｐｒｅｃｕｒｓｏｒ,ａｌｏｔｏｆｏｒｇａｎｏｌａｎｔｈａｎｉｄｅｃｈｌｏｒｉｄｅｃｏｍｐｌｅｘｅｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄａｎｄｓｔｒｕｃｔｕｒａｌｌｙｃｈａｒａｃｔｅｒｉｚｅｄ[1].Ｔｈｅｂｉｍｅｔａｌｌｉｃｃｏｍｐｌｅｘｅｓｃｏｎｔａｉｎｉｎｇａｌｋａｌｉｍｅｔａｌ,Ｃｐ2Ｌｎ(μＣｌ)2Ｍ(Ｌ)(Ｃｐ=η5Ｃ5Ｈ5ｏｒＣ5Ｍｅ5;Ｍ=Ｌｉ,Ｎａ;Ｌ=ＴＨＦ,ＴＭＥＤＡ),ｉｓａｍａｉｎｓｔｒｕｃｔｕｒｅｔｙｐｅ.Ｉｎｔｈｅｃｏｕｒｓｅｏ…     

Photochemistry of f-element ions

Published data on photochemical reactions of f-element compounds, namely, uranyl ion and lanthanide and actinide ions, are surveyed and analyzed. The types of reactions of photoexcited ions, reaction mechanisms, and analytical applications of the photochemical methods for the separation, isolation, and determination of f-elements are considered.     

KBr-RE(La,Sm)Br3-13%HBr-H2O四元体系25℃时的相平衡研究

Meyer在研究K。REBr。（RE一La,Sin）的结构及热力学性能时,引用文献的方法合成了2：1型化合物见s．其具体反应机理尚未明确表示．根据文觎',合成2：1型化合物CSZLUCI。分两步：第一步是LtJ;03与CSCI在氢氯酸介质中反应,生成2：1型含结晶水的中间体CS入llCI;·H20;第二步是中间体在HCI气氛下的高温脱水反应．反应如下：HC＊＊;HCI;＊ISOOC4CSCI＋l。LI,O。、ZCS,LSCI。·H,O、ZCS,LllCI。－H人）由上述反应过程可见,中间体的形成实际上应是LLICI。与CSCI在HCI介质中反应的生成物．那么,Meye…     

CO加氢合成C2含氧化合物Rh-Sm/SiO2催化剂的研究

使用加压下的CO加氢反应、程序升温还原(TPR)、吸附氢的程序升温脱附(H2-TPD)以及CO和H2吸附等技术,研究了Rh-Sm/SiO2催化剂上Sm促进剂对合成二碳含氧化合物的促进效应.结果表明,Sm加入到Rh/SiO2中使催化剂的活性和二碳含氧化合物的选择性显著提高,催化剂上的Sm3+不易被还原,Sm的加入起着提高Rh分散度的作用,使催化剂上CO和H2的吸附量增大,倾向于促进乙酸和乙醛的生成.     

Transformation of the cationic growing center of poly(tetrahydrofuran) into an anionic one by bis(pentamethylcyclopentadienyl)samarium

Transformation of the cationic growing center of living poly(tetrahydrofuran) [poly(THF)] into an anionic one was achieved in high efficiency (62%) by the end-capping of living poly(THF) with potassium iodide followed by the reduction with bis(pentamethylcyclopentadienyl)samarium (Cp*₂Sm), whereas the direct reduction with Cp*₂Sm without the end-capping resulted in the formation of poly(THF) with pentamethylcyclopentadienyl group at the terminal. The increase in the molecular weight of poly(THF) after the reduction was observed, which indicates the presence of the dimerization of poly(THF) during the reduction. The polymerization of a variety of electrophilic monomers including δ-valerolactone, 2-oxo-1,3-dioxane, and alkyl methacrylates with the macroanion provided good yields of the corresponding block copolymers consisting of both cationically and anionically polymerizable monomers. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2209–2214, 1998