SAPO－5，－11和－34分子筛模板剂的脱除及其结构的热致变化

用水热法合成了ＳＡＰＯ－５，－１１和－３４硅磷酸铝类分子筛。并对经不同温度焙烧处理的样品进行表征，结果表明：分子筛中模块剂的热分解过程与其结构和孔大小有较大的关系。在ＳＡＰＯ－５和ＳＡＰＯ－３４分子筛中，外部联接的Ｔ－Ｏ－Ｔ键的反对称伸缩振动峰（１２４０ｃｍ~（－１）－１０３８ｃｍ~（－１））和其对称伸缩振动（７３４ｃｍ~（－１）－６００ｃｍ~（－１））及双环的变形振动（６００－５００ｃｍ~（－１））的吸收峰对样品的结晶度比较敏感。但在ＳＡＰＯ－１１中，分子筛骨架中Ｔ－Ｏ－Ｔ反对称伸缩振动（１２２５ｃｍ~（－１）和１０３８ｃｍ~（－１））随结晶度的下降而基本保持不变，但内四面体（ＴＯ_４）的对称伸缩振动，反对称伸缩振动峰及Ｔ－Ｏ弯曲振动峰随样品焙烧温度的升高而减弱并分裂。红外吸收带向低频方向移动。ＳＥＭ－ＥＤＡＸ结果表明：随样品焙烧温度的升高，结晶度下降，分子筛晶形变得不规则，晶面越来越粗糙，但结晶度的下降并非由于其中ＰＯ_４四面体的热分解所引起，而是由外部联结的Ｔ－Ｏ－Ｔ键的断裂，双环被破坏及骨架元素间的重排所引起。     

聚乙烯拉伸过程中晶态变化及形变机理

用红外光谱和X-射线衍射研究了室温拉伸的聚乙烯,结果显示单斜晶存在于室温拉伸的聚乙烯中。对Hendra等关于拉伸过程机理的“微熔融”理论及其所根据实验结果提出异议,而本文的,实验结果支持了Peterlin模型。     

Why is space three-dimensional and how may groups be seen?

First we propose a model of visual perception essentially based on the Keldysh-Chernavsky-Sossinsky three-channel theorem, from which three-dimensionality of space follows. Second, we associate with a system of subgroups H ₁, ..., H_s of a given group G a geometric object, called a group crystal, in order to visualize G. How this notion works is illustrated via the Burnside problem.     

On Bateman's method for second kind integral equations

Summary Under suitable conditions, we prove the convergence of the Bateman method for integral equations defined over bounded domains inR ^d ,d1. The proof makes use of Hilbert space methods, and requires the integral operator to be non-negative definite. For one-dimensional integral equations over finite intervals, estimated rates of convergence are obtained which depend on the smoothness of the kernel, but are independent of the inhomogeneous term. In particular, for aC kernel andn reasonably spaced Bateman points, the convergence is shown to be faster than any power of 1/n. Numerical calculations support this result.     

羟基铝溶液及铝交联蒙脱土的研究

本文用(27)~Al NMR法和8-羟基喹啉萃取法分别研究了羟基铝溶液中十三聚铝含量的变化规律,还用X-射线衍射法研究了铝交联蒙脱土d_(001)的变化。研究结果表明,铝离子的聚合情况主要由羟铝比决定,而浓度影响不大。随着羟铝比的增加,溶液中单核铝离子含量减少,十三聚铝离子相对含量增加,所得铝交联蒙脱土的d_(001)也随之增大。参照这些变化规律、控制羟基铝溶液的组成,可以制备各种层柱状铝交联蒙脱土复合物。     

手性3,5-二甲基-2-芳基-2-吗啉醇盐酸盐的合成及其晶体结构

以(S)-2-氨基丙醇为手性源与α-溴-3-氯苯丙酮反应, (R)-2-氨基丙醇为手性源与6-甲氧基-2-(2-溴丙酰基)萘反应, 分别合成了手性纯化合物(2R,3R,5S)-3,5-二甲基-2-(3-氯苯基)-2-吗啉醇盐酸盐(4a)和(2S,3S,5R)-3,5-二甲基-2-(6-甲氧基-2-萘基)-2-吗啉醇盐酸盐(4b), 利用X射线单晶衍射仪测定了两化合物的晶体结构和两化合物的空间结构, 并初步分析两化合物空间结构, 化合物4a晶体属正交晶系, 空间群为P2₁2₁2, 晶胞参数为: a＝0.8718(2) nm, b＝0.7883(2) nm, c＝2.0247(6) nm, Z＝4, V＝1.3915(7) nm³, D_c＝1.328 g/cm³, F(000)＝584, R₁＝0.0399, wR₂＝0.0797, S＝1.042. 化合物4b晶体属正交晶系, 空间群为P2₁2₁2₁, 晶胞参数为: a＝0.71035 (9) nm, b＝0.77703(10) nm, c＝2.9820(4) nm, Z＝4, V＝1.6318(4) nm³, D_c＝1.318 g/cm³, F(000)＝688, R₁＝0.0520, wR₂＝0.1108, S＝0.994.     

N(nPr)4[B5O6(OH)4][B(OH)3]2 and N(nBu)4[B5O6(OH)4][B(OH)3]2: Clathrates with a diamondoid arrangement of hydrogen-bonded pentaborate anions

Single-crystal X-ray structure analyses of N(nPr)₄[B₅O₆(OH)₄][B(OH)₃]₂,1, and N(nBu)₄ [B₅O₆(OH)₄][B(OH)₃]₂,2, reveal that these materials are novel clathrates, the isotypic host structures of which are three-dimensional assemblies of hydrogen-bonded [B₅O₆(OH)₄]^– ionsand B(OH)₃ molecules. The assembly of only the pentaborate anions is a distorted (i.e., along [102] elongated) fourconnected diamond-related network. The N(nPr) ₄ ⁺ and N(nBu) ₄ ⁺ ions are trapped within the complex three-dimensional channel systems of the host frameworks. Both1 and2 crystallize monoclinically with space groupP2₁/c andZ=4. The cell constants are:1:a=13.592(5),b=12.082(2),c=17.355(6) Å, =106.60(2)° (298K);2:a=13.874(3),b=12.585(1),c=17.588(4) Å, =107.04(1)° (238 K). The results obtained by both¹¹B and¹³C MAS NMR spectroscopy are discussed. Thermogravimetric studies under a flowing inert-gas atmosphere suggest that water, stemming from polycondensation of the hydrous borate species, is released from the clathrates at ca. 443 K (1) and 398 K (2) before the decomposition of the organic cations starts at ca. 603 K (1) and 603 K (2).Author for correspondence. Supplementary Data relating to this article are deposited with the British Library as supplementary publication No. SUP 82172 (82 pages).     

Reactions of bis(hexamethylbenzene)iron(0) with carbon monoxide and with unsaturated hydrocarbons

Thermal decomposition of bis(hexamethylbenzene)iron(0) in the presence of carbon monoxide yields a novel carbonyl iron complex, [C₆(CH₃)₆]Fe(CO)₂. The cyclohexadiene complex [C₆(CH₃)₆]Fe(C₆H₈) is obtained from reaction of bis(hexamethylbenzene)iron(0) with either 1,3-cyclohexadiene or benzene, and the yield is much greater in the presence of hydrogen gas. Interaction of bis-(hexamethylbenzene)iron(0) with 2-butyne induces a catalytic cyclotrimerization to give more hexamethylbenzene. Kinetic and isotope distribution studies indicate that the primary step in these reactions is not a direct loss of one ring ligand, but rather an insertion of the iron center into one of the ligand methyl CH bonds, leading to a benzyl hydride complex species. Mechanisms for the subsequent reactions of this iron hydride species are proposed.     

Crystal Structure and Biological Activities of （R）-N′-[2-（4-Methoxy-6-chloro）-pyrimidinyl]- N-[3-methyl-2-（4-chlorophenyl）butyryl]-urea

1 INTRODUCTION The acyl ureas are a kind of high biological acti- vity compounds with low toxicity to mammals, birds, fish, amphibians, etc., and significant organic synthe- sis intermediates working extensively as insecticides, pesticides, fungicides and herbicides in agrochemi- cal industry[1～7]. While pyrimidinyl derivatives show excellent biological activities in the development of pesticide, and are used to develop high effective and high select herbicides. For example, pyrimidiny su…     

西印度蔗螟聚集信息素次要组份合成方法的改进

2-甲基-4-庚醇和2-甲基-4-辛醇是西印度蔗螟(Metamasiushemipterus)聚集信息素的次要组份，本文以天然产物(S)-亮氨酸为原料合成出了2-甲基-4-庚醇及2-甲基-4-辛醇的所有对映异构体，其关键步骤是由(2S)-4-甲基-1,2-戊二醇合成出(2S)和(2R)-4-甲基-1,2-环氧戊烷两种重要中间体，目标产物光学纯度可达95%以上。