Solution and X-Ray Crystal Structures of the Di- and Tetra-allyl Ether of tert- utylcalix[4]arene

The di- and tetra-allyl ethers of tert-butylcalix[4]arene 1 and 2 have been prepared by alkylation of tert-butylcalix[4]arene with allyl bromide and K₂CO₃ using different reaction times. Solution ¹H NMR measurement of the di-allyl ether 1 and X-ray crystal structures of the complexes of 1 with chloroform (1a) or methanol (1b) indicate the cone conformation of 1 in which intramolecular hydrogen bonding can be maximized. The crystalline state conformers 1a and 1b are distorted in different grades depending on the solvent. While methanol is incorporated in the macrocycle, chloroform molecules do not occupy the cage. The solution ¹H NMR spectra of tetra-allyl ether 2 show the co-existence of the cone and partial cone conformation. The partial cone conformer of 2 was investigated by X-ray crystallography. In this compound hydrogen bonding is not existent. The conformer distribution is likely affected by steric and template effects.     

铜(Ⅱ)-邻菲咯啉-(邻菲咯啉-5,6-二酮)络合物的合成及其同脱氧核糖核酸的作用

以邻菲咯啉（phen)、邻菲咯啉－5，6－二酮（dione)为配体首次合成了高氯酸邻菲咯啉－邻菲咯啉－5，6－二酮（Ⅱ）。用荧光光谱，摩尔比，粘度，MLCT减色效应，平衡常数以及荧光能量转移研究了各合物与鱼精子DNA的结合情况，证实了该络合物与DNA存在插入作用。基于络合物对DNA能量转移造成荧光量子产率比值（Φλ/Φ320）的降低，解释了不同波长激发光下，荧光发射峰在加入DNA后产生猝灭和增强两种绝然不同的现象。     

Non-catalytic Addition of 1,2,4-Triazole to Nucleophilic and Electrophilic Alkenes

Non-catalytic addition of 1,2,4-triazole to vinyl ethers and esters occurs on heating (65-175°C, 4-20 h) to give Markovnikov adducts (yield 30-100%). Electron-deficient alkenes (acrylonitrile, acrylic acid, 4-phenyl-3-buten-2-one) react with 1,2,4-triazole (78-190°C, 4-20 h) to give anti-Markovnikov adducts in yields of 45-83%.     

A doubly deprotonated form of calix[6]arene: Crystal and molecular structure of (calix[6]arene-2H)2−·(HNEt 3 + )2

The doubly deprotonated form of calix[6]arene, with two protonated triethylamines as counter-ions, crystallizes in the monoclinic system: space groupP2₁/n,a=8.465(4),b=17.822(8),c=15.182(6) Å,=90.18(4)°,V=2291(2) ų,Z=2. Refinement led to a final conventionalR value of 0.063 for 1046 reflections. The macrocycle conformation is not apinched cone, usual for freeR-calix[6]arene, but a distorted 1,2,3-alternate cone, since the molecule lies on a symmetry center. Furthermore, one of the torsion angles defined by the methylene bridges is near to zero, which is unusual in calixarene structures. Supplementary Data relating to this article (atomic coordinates for hydrogen atoms, anisotropic displacement parameters for oxygen and nitrogen atoms, and observed and calculated structure factors) are deposited with the British Library as Supplementary Publication No. SUP 82182 (7 pages).     

Cu/SO42-/La2O3-ZrO2-Al2O3催化剂的制备及其对C3H6选择还原NO的催化性能

以Al₂O₃为基质，添加ZrO₂和La₂O₃，制成La₂O₃-ZrO₂-Al₂O₃复合载体，然后采用SO₄^2-进行改性，再负载上Cu²⁺，制备了铜基SO₄^2-改性的复合载体催化剂(Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃)。考察了它在富氧条件下对丙烯选择还原NO的催化性能，并借助XRD、SEM、TG、Py-IR、NH₃-TPD、FTIR和TPR等方法研究了Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃的结构和性能的关系。结果表明，ZrO₂的加入主要有利于提高催化剂的低温活性；La₂O₃的加入则主要有利于提高催化剂的热稳定性和还原性能；SO₄^2-能够与Zr形成螯合双配位结构，大幅度促使催化剂表面酸量增加并且酸性增强；因此，有效地提高了Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃在富氧条件下对丙烯选择还原NO的催化活性和水热稳定性。在无水条件下，Cu/SO₄^2-/La₂O₃-ZrO₂-Al₂O₃能使NO的最大转化率高达84.3%，即使在275 ℃ 10%水蒸气存在的情况下，仍能使NO的转化率高达81.2%。     

A new approach to the facile synthesis of mono- and disubstituted quinazolin-4(3H)-ones under solvent-free conditions

Quinazolin-4(3H)-one derivatives were synthesized successfully via a one-pot, three component reaction of isatoic anhydride and an orthoester with ammonium acetate or a primary amine catalyzed by silica sulfuric acid under solvent-free conditions. This is the first report on the synthesis of 2-substituted quinazolin-4(3H)-ones by this procedure.     

锂离子筛的制备及其交换性能研究

用浓度为0.5mol/L的盐酸对高温固相合成的前体LiMn2O4进行酸洗脱锂,制得锂离子筛HMn2O4,并在不同pH值和温度下进行了Li 交换性能的研究,同时运用XRD和TEM进行了相应表征。结果表明,锂离子筛吸附交换前后晶体结构只发生了细微变化,但都仍为尖晶石型结构;交换反应在前10min速率最快,约20min就趋于平衡;Li 交换总量随pH值增大而升高,其中pH=7时交换容量为18.5526mg/g;Li 交换量和交换选择性随温度的升高而显著增强。     

Synthesis and Crystal Structure of the Copper Complex of 7，16-Bis（2-hyd roxy-5-met hylbenzyl）-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane

A lariat crown ether ligand 7,16-bis (2-hydroxy-5-methylbenzyl)- 1,4,10,13-tetraoxa-7,16-diazacyclooctadeeane (L1) has been prepared via one-pot Mannich reaction. Its copper(Ⅱ) complex Cu-L1 was synthesized and characterized by elemental analysis, IR and UV-visible spectroscopy. The crystal structure of the complex has been determined by X-ray diffraction analysis. The result shows that the copper(Ⅱ) ion is six-coordinated by two nitrogen and four oxygen atoms, two from the crown ether and the other two from the deprotonated phenolate anions, forming an elongated octahedral complex. Electrochemical study indicates that the complex undergoes reversible reduction in DMF solution.     

LiMn2O4的湿法合成及锰的光度法测定研究

The LiMn₂O₄ spinel was prepared by wet method using Li₂CO₃， Mn(CH₃COO)₂·4H₂O and CO₂ as raw ma-terials. The products were measured by TG/DTA， XRD， IR. The results Showed that the sample calcined at 800℃ for 10h was well crystallized monophase product. The contents of Mn(Ⅲ) and Mn(Ⅳ) of LiMn₂O₄ spinel were determined simultaneously by spectrophotometric analysis with pyrophosphoric acid.     

QSAR Studies on the COX-2 Inhibition by 3,4-Diarylcycloxazolones Based on MEDV Descriptor

Selective inhibition of cyclooxygenase-2 (COX-2) might avoid the side effects of current available nonsteroidal antiinflammatory drugs while retaining their therapeutic efficacy. A novel variable selection and modeling method based on prediction is developed to construct the quantitative structure-activity relationships (QSAR) between the molecular electronegativity distance vector (MEDV) based on 13 atomic types and the biological activities of a set of selective cyclooxygenase-2 inhibitory molecules, 3,4-diarylcycloxazolones (DAA) plus indomethacin,naproxen, and celecoxib. Using multiple linear regression, a 5-variable linear model is developed with the calibrated correlation coefficient of 0.9271 and root mean square error of 0.17 in modeling stage and the validated correlation coefficient of 0.9030 and root mean square error of 0.20 in leave-one-out validation step, respectively. To further test the predictive ability of the model, 20 DAA compounds are picked up to construct a training set which is used to build a QSAR model and then the model is employed to predict the biological activities of the balance compounds. The predicted correlation coefficient and root mean square error are 0.9332 and 0.19, respectively.