DETECTION OF ACTIVE RADICALS FORMED DURING THE SONOLYSIS OF POLYMERS

Active radicals formed during the sonolysis of PVK (polyvinyl carbazole) and PMMA (polymethylmethacrylate) have been studied with the combination of spin thepping technique and ESR spectroscopy-The results show that: 1. For PVK, radicals CA and--CH_2--CH--are produced during the ultrasonic irradiationand only the later can be trapped by MNP. 2. For PMMA, radicals --C and --CH_2 are grnerated by sonolysis and both can be trappedby ND.     

新的四氢叶酸辅酶模型及与亲核试剂反应生成物的核磁共振研究

对新合成的四氢叶酸辅酶模型碘化１，２二甲基３对甲氧苯磺酰基咪唑啉及与亲核试剂反应后生成的产物进行了１ＨＮＭＲ谱的研究，通过化学位移及偶合常数研究探讨其规律性。     

Hydrothermal Synthesis, Crystal Structure and Fluorescent Property of a Keggin Polyoxometalate [Cu~I(2,2'-bipy)_2]_3[PW~(Ⅵ)_(12)O_(40)]

1 INTRODUCTION Polyoxometalates (POMs) have become a focus of contemporary chemical research due to their structure diversity and potential applications in many areas, such as catalysis[1], photochemistry[2], magnetism[3], etc. In this field, POMs containing Keggin moieties have received considerable attention. A large num- ber of efforts have been given to the decoration of POMs with various transition metal complexes and organic moieties[4]. To date, several compounds con- taining …     

Synthesis,Crystal Structure and Norbornene Polymerization of a Palladium(Ⅱ) Complex Based on Phenoxyimine Ligand

The title complex N,O-bis{2-[[(2,6-benzhydryl-4-methylphenyl)imino]-methyl]-phenol}-palladium(II)(C_(80)H_(64)N_2O_2 Pd) has been synthesized by the reaction of 2-[[(2,6-benzhydryl-4-methylphenyl)imino]-methyl]-phenol with Pd(CH_3COO)_2, and characterized by IR spectrum and elemental analysis. The spatial structure of the complex has been verified by single-crystal X-ray diffraction analysis. The compound belongs to the monoclinic system, space group P21/n with a = 13.492(3), b = 16.924(3), c = 14.135(3) ?, β = 97.84(3)°, V = 3197.4(11) ?~3, C_(80)H_(64)N_2O_2 Pd, Mr = 1191.73, Z = 2, Dc = 1.238 Mg/m~3, μ = 0.339 mm~(-1), F(000) = 1240, T = 293(2) K, the final R = 0.0593 and wR = 0.1192(I 2s(I)). The compound showed excellent catalytic activity up to 1.130 × 10~7 g of PNB(mol of Pd)~(-1)h~(-1) for the addition polymerization of norbornene by using methylaluminoxane(MAO) as a cocatalyst.     

含α-氨基酸的新型有机锗化合物的合成与生物活性研究

设计合成了两个系列20个含α-氨基酸的新型有机锗化合物, 对化合物进行了波谱表征, 用X射线衍射测定了化合物Ph3GeCH(Ph)CH2CONHCH(CH2COOC2H5)COOC2H5的晶体结构. 抗肿瘤实验结果表明, 这两个系列的化合物有一定的抗KB, HCT-8和Bel-7402活性.     

矩阵Hoffman-Wielandt型乘法相对扰动界

<正>1引言设A是一个方阵,(?)是它的扰动矩阵.特征值的加法扰动和乘法扰动是矩阵特征值的两种不同类型的扰动.当(?)=A+E时,称(?)是A的加法扰动矩阵;当(?)=D_1~*AD_2时,其中     

L-苏式二氢鞘氨醇的立体选择性合成

二氢鞘氨醇（ＤＨＳ）是２－氨基－１，３－二羟基的饱和长链氨基醇化合物，是构成鞘脂类（包括鞘磷脂和糖鞘脂）的主链部分．由于鞘脂类在自然界中来源稀少，又很难得到纯品．因此，作为鞘脂类主链部分的二氢鞘氨醇的合成有重要的意义［１］．二氢鞘氨醇有两个手性碳，共...     

氰基蒽的电子转移荧光猝灭及激基复合物

本文测定了在不同溶剂中一系列化合物以及氧分子对9,10-二氰基蒽(DCA)及9-氰基蒽(CNA)的荧光淬灭常数k_q值及DCA与2,5-二甲基呋喃的激基复合物的发射光谱。这些化合物的k_q值与计算所得自由能的变化△G之间的关系基本符合Rehm-Wdler关系。溶剂极性及溶剂粘度对荧光猝灭反应有影响,影响强电子给体k_q值的主要因素是溶剂的粘度,而弱电子给体的k_q值则主要决定于溶剂的极性。氧分子的k_q值基本上与溶剂扩散速率常数走k_diff值吻合。     

氰基芳香化合物与四氯化碳之间电荷转移的相互作用

本文以正己烷为惰性参考溶剂,测定了9,10-二氰基蒽(DCA), 9-氰基蒽(CNA),1-氰基萘(1-CN), 对二氰基苯(p-DCB)在四氯化碳中的紫外吸收光谱, 荧光光谱以及DCA,CNA与四氯化碳1:1的配位平衡常数, 并讨论了这些氰基芳香化合物与四氯化碳之间的电荷转移相互作用.     

硫化镉光催化氧化二苯甲醇的反应

半导体粉能对烯烃, 芳烃等的光催化氧化, 但效率低, 揭示其机理, 研究提高催化效率是研究半导体光催化的突出问题. 本文研究了硫化镉粉末光催化氧化二苯甲醇的反应, 发现能从硫化镉导带上捕获电子的物质都能促使电荷分离, 引发或加速反应, 而自由基猝灭剂却能完全猝灭反应. 本文进一步揭示了硫化镉光催化特性并探讨了反应机理.