Tetramethyldisilan-1,2-diyl-verbrückte Dicyclopentadienyl-und Diindenylmetalldichloride der 4. Gruppe – Kristallstruktur von

Tetramethyldisilane-1,2-diyl bridged Dicyclopentadienyl and Diindenyl Metal Dichlorides of the Group 4 Metals – Crystal Structure of Dicyclopentadienyl and diindenyl metal dichlorides of the type Cp′? SiMe₂SiMe₂? Cp′MCl₂ (Cp′ = C₅H₄, M = Ti ( 1 ), Zr ( 2 ), Hf ( 3 ); Cp′ = C₉H₇, M = Zr ( 4 ), Hf ( 5 )) were synthesized and characterized by means of their ¹H, ¹³C, ²⁹Si-n.m.r., MS, and IR spectra. The crystal structure of 2 was determined.     

THF—FER沸石的系列研究—1．晶体结构稳定性

四氢呋喃（THF）-Na2O-SiO2-Al2O3-H2O体系水热合成的THF-FER沸石，经酸交 换-焙烧脱THF（Ⅰ）或焙烧脱THF-酸交换（Ⅱ）的不同方式处理，均可制得低钠H- FER沸石。经XRD，^27Al与^29Si MAS NMR,低温氮吸附等表征证明，通过1273K高温 的热处理和1073K饱和水蒸气下的水热处理，H-FER沸石骨架保持高度稳定。在高温 水蒸气作用下，Si(2Al）容易从骨架上脱离，而Si(1Al）则保持相对稳定，以（Ⅱ ）方法处理，制备的H-FER沸石在水热条件下易产生较多的硅差劲基缺陷。经高温 热和水热处理后，H-FER沸石孔道结构基本保持完美、开放。     

Selective Oxidation of Betulin by Cr(VI) Reagents

Oxidation of betulin by pyridinium dichromate, pyridinium chlorochromate, and K₂Cr₂O₇ -H₂SO₄ in the presence of tetrabutylammonium bromide was studied. Products of regioselective C-3, C-28-, and exhaustive oxidation, 28-hydroxylup-20(29)-3-one, 3-hydroxy- and 3-oxolup-20(29)-en-28-al were obtained.     

Molekulares S=GeCl2 Matrix-IR-Untersuchungen und ab initio SCF-Rechnungen

The Molecule S?GeCl₂. Matrix IR Investigation and Ab initio SCF Calculation Molecular S?GeCl₂ is found in a matrix reaction between the high-temperature molecule Ge?S and Cl₂. A structure analog to that of phosgene can be derived from the isotopical shifts (⁷⁰Ge/⁷²Ge/⁷³Ge/⁷⁴Ge/⁷⁶Ge and ³⁵Cl/³⁷Cl) within the IR spectra. The normal coordinate analysis results for the Ge?S force constant a value of 4.21 mdyn/Å. The spectroscopic results are confirmed by ab initio SCF calculations.     

Zur Reaktion von Hydrazinen mit Fluorsilanen und lithiierten Aminen

Lithium salts of hydrazines react with fluorosilanes under formation of fluorosilylhydrazines and LiF. Five membered rings are obtained in the reaction of bis(fluorosilyl)-hydrazines with lithiated amines. The mass,¹H-and¹⁹F-nmr spectra of the compounds are reported.

     

Darstellung und Strukturen einiger N-(Tri-t-butoxysilyl)anilin-Derivate

Formation and Structures of N-(tri-t-butoxysilyl)aniline Compounds Para-substituted N-(tri-t-butoxysilyl)anilines (t-BuO)₃SiNRC₄H₄X-p, R = H, CH₃, with substituents of high electron affinity (X = CN, NO₂) were prepared by a one-pot reaction of tri-t-butoxychlorsilane, potassium t-butanolate and substituted anilines. Corresponding compounds with substituents of low electron affinity (X = OMe, H) preferably were prepared by metalation of anilines with sodium amide. Four crystal structures were determined. N-(tri-t-butoxysilyl)-p-nitro-aniline, N-methyl-(N-tri-t-butoxysilyl)-p-nitroaniline and N-(tri-t-butoxysilyl)-p-cyanoaniline crystallize at 298 K monoclinically, N-(tri-t-butoxysilyl)aniline crystallizes orthorhombically.     

Darstellung und Charakterisierung der Trisilylphosphane (Ph 3Si) n P(SiMe 3)3−n,n=1,2,3

A simple preparation of the title compounds is achieved by reacting Na₃P/K₃P with stoichiometric mixtures of chlorotriphenylsilane and chlorotrimethylsilane.³¹P- and²⁹Si-NMR-Data as well as Ir and Raman spectra of the compounds are reported.

     

钕对Mg-5Al-1Si高温蠕变及组织性能的影响

研究了不同Nd含量对Mg-5Al-1Si镁合金的高温蠕变性能影响, 对析出相进行了分析, 研究了微观组织与力学性能的关系. 研究结果表明, 该合金中的主要强化相Mg2Si呈粗大的汉字状, 分布在晶界的周围, 在受到应力时, 这种汉字状相与基体的界面处易产生微裂纹, 降低合金的抗拉强度、塑性等力学性能. 在Mg-5Al-1Si合金中加入微量的Nd以后, 合金的组织得到明显的细化, 并使Mg2Si强化相形貌由粗大的汉字状转变为细小、弥散分布的颗粒状. 由于显微组织的改善, 使得Mg-5Al-1Si镁合金的室温和高温力学性能均有一定的提高, 并明显的改善了Mg-5Al-1Si的抗蠕变性能.     

Si-VPI-5分子筛的多核固体NMR研究

磷酸铝类分子筛是近年来继Y型和ZSM七分子筛之后的第三代合成分子筛材料，其骨架由A10。和P0。四面体均匀交替地组成问．由于带负电行的A10。和带正电荷的PO。四面体数目相等，整个骨架呈电中性，所以这类分子筛本身无离子交换能力和催化活性．当用硅或某些金属离子（如Mg、Fe、Co、Zn等）对磷酸铝分子筛进行同晶取代，就会在骨架上造成电行不平衡，从而使这类分子筛具有一定的离子交换能力和酸性【习．因而对硅或金属离子在磷酸错类分子筛中取代机理的研究一直是人们感兴趣的问题问．Vpl－5是最近才合成出来的具有18圆环一维孔结构的…