反应型受阻胺-4-丙烯酰胺基-2,2,6,6-四甲基哌啶(AATP)熔融本体光聚合反应动力学研究

合成了反应型受阻胺4-丙烯酰胺基-2,2,6,6-四甲基哌啶(AATP),用FTIR、¹H-NMR和元素分析对其结构和组成进行了综合表征.以AATP为聚合单体,利用光-DSC技术研究了AATP熔融本体光聚合反应动力学.结果表明:AATP光聚合的诱导时间随引发剂浓度和辐照光强增加而缩短,光聚合速率随温度的升高而减小;在聚合初期,AATP光聚合速率分别与引发剂浓度和辐照光强的平方根呈较好的线性增长关系.并用稳态和非稳态相结合的光-DSC方法测定了AATP光聚合过程的动力学参数:链增长速率常数k_p=2.22-7.96×10²L/mol·s、链终止速率常数k_t=0.08-2.67×10⁴L/mol·s、表观活化能为E_p-E_t/2=-7.70-13.36kJ/mol、指前因子A_p/A_t^0.5=0.076-0.333(L/mol·s)0.5,k_p和k_t在聚合初期均随单体转化率的提高而增大,但kt增加的幅度远大于k_p.     

Oxidation of N-(2,2,6,6-Tetramethyl-4-piperidinyl)-aminoalkanephosphonates

Abstract

The N-(2,2,6,6-tetramethyl-4-piperidinyl)aminoalkanephosphonates 1 were synthetized by the addition of dialkyl phosphonates to the imines of 4-amino-2,2,6,6-tetramethylpiperidine. Acid hydrolysis of the obtained esters 1 (leads to the free aminoacids which were by exchange ion chromatography.     

Novel Reaction of Nitroxide with Hantzsch Dihydropyridines

Nitroxides have been found to be the intermediate in the in vivo metabolism of hydroxamic acid, a well-known biological molecule1. Structural modification of some antitumor drugs by introducing nitroxides can lower toxicity remarkably with retention or even increase of the antitumor activity2. Furthermore, the use of nitroxides as spin probes makes it possible to get information regarding the microenvironment of the reaction. 4-Substituted Hantzsch 1,4-dihydropyridines (DHP) are analogs …     

溴酸钠和氯化铁为助催化剂2,2,6,6-四甲基-N-氧化哌啶催化醇的氧化

建立了溴酸钠和氯化铁为助催化剂2,2,6,6-四甲基-N-氧化哌啶(NaBrO₃-FeCl₃-TEMPO)新型催化体系,以苯甲醇的氧化为研究对象,得出各成分与底物的最佳物质的量比为:2%TEMPO、35%NaBrO₃、3.7%H₂SO₄、2%FeCl₃·6H₂O。该体系在室温下可有效实现芳香醇、脂肪醇及杂环醇的氧化,收率高(99%)、选择性强(99%),在无氧条件下,仍表现出较好的催化活性。     

Oxidation of Primary Alcohol Groups of Naturally Occurring Polysaccharides with 2,2,6,6-Tetramethyl-1-Piperidine Oxoammonium Ion

ABSTRACT

The primary alcohol groups of ten polysaccharides, with widely different structures and water solubilities, were oxidized to carboxyl groups using 2,2,6,6-tetramethyl-1-piperidine oxoammonium ion (TEMPO) at pH 10.8 and 0°C. The yield and selectivity for the primary alcohol group were high for all ten of the polysaccharides. The oxidation greatly increased the water-solubility of the polysaccharides. Water-insoluble polysaccharides such as amylose, cellulose, and chitin became water-soluble to the extent of approximately 10% (w/v). The water-soluble polysaccharides had their degree of solubility doubled or tripled. The specific optical rotation, viscosity, and gelling properties with calcium ion were determined. The oxidized polysaccharides are new anionic polymers with unique structures that could have application as gums, gels, and films.     

吩噻嗪与四甲基哌啶氧铵正离子的电子转移反应动力学研究

以Marcus半经典电子转移理论为基本框架, 改进了重组能的计算方法, 建立了一套研究自交换和交叉电子转移反应的理论方案。用密度泛函理论和半经验分子轨道理论具体研究了四甲基哌啶氧铵正离子与吩噻嗪在乙腈溶液中的交叉电子转移反应以及相应的2个自交换反应的动力学性质, 计算了反应的活化能、重组能、耦合矩阵元等有关参数,获得了和实验结果相一致的电子转移速率常数。     

侧链含自由基单元的1,4-吡咯并吡咯二酮共轭聚合物的合成和半导体性质研究

合成了两个侧链含有2,2,6,6-四甲基哌啶-1-氧自由基单元(TEMPO)的1,4-吡咯并吡咯二酮(DPP)共轭聚合物PDPP4T-1和PDPP4T-2,并开展了其半导体性质研究。薄膜场效应晶体管器件测试结果显示,相对于不含TEMPO的聚合物PDPP4T,PDPP4T-1和PDPP4T-2的场效应器件性能有所降低,不过,含TEMPO的聚合物器件性能最高仍达到了2.12cm²·V^-1·s^-1。进一步通过原子力显微镜和X射线衍射对TEMPO引入后导致性能降低的可能原因进行了研究。     

Reaction of 3,3,6,6-Tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-diones with Lithium Aluminum Hydride

The corresponding 3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydroacridines have been obtained by the interaction of 3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8,9,10-decahydroacridine-1,8-dione, its 9-Ph- and 9-p-MeOC₆H₄-substituted derivatives with lithium aluminum hydride. The reaction proceeds in boiling diglyme and also at room temperature on extended stirring of the reactants in ether.     

Kinetic Investigation of the Reaction of Octacarbonyl Dicobalt with 2,2,6,6-Tetramethylpiperidin-1-oxyl

The initial rate of carbon monoxide evolution in the reaction of Octacarbonyl dicobalt with 2,2,6,6-tetramethylpiperidin-1-oxyl free radical (TEMPO) at 15°C in n-octane solution leading to the 16e complex (TEMPO)Co(CO)₂ was found to be first order with respect to the TEMPO concentration, 0.5 order with respect to the Co₂(CO)₈ concentration, and negative 0.5 order with respect to the CO concentration. Scavenging ·Co(CO)₄ and ·Co(CO)₃ by the free radical TEMPO in the rate-determining steps are in accord with the kinetic observation. The observed rate constant is k _obs = 6.4 × 10^–5 s^–1.     

原子转移氮氧自由基偶合反应制备聚苯乙烯改性的石墨烯

通过原子转移氮氧自由基偶合(ATNRC)反应制备了聚苯乙烯改性的石墨烯. 先将氧化石墨烯酰氯化, 然后与2,2,6,6-四甲基-4-羟基哌啶-1-氧自由基(HTEMPO)进行酯化反应制备HTEMPO 修饰的石墨烯(Graphene-HTEMPO), 通过Graphene-HTEMPO 与原子转移自由基聚合(ATRP)方法制备的Br 封端的聚苯乙烯进行ATNRC 反应, 即可得到聚苯乙烯共价改性的石墨烯(Graphene-g-PS). 热失重分析结果表明聚苯乙烯的接枝率约为6.68 wt%, 从透射电镜照片中也可以明显地看到石墨烯表面的聚苯乙烯. 由于聚苯乙烯的共价接枝, 使得Graphene-g-PS 在氯仿、正己烷、甲苯、甲醇等有机溶剂中具有很好的分散性, 有利于石墨烯的进一步应用.     

Alkylation of 2,2,6,6-tetr amethyl-4-oxopiperidine and 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl enamines by mannich bases from β-naphthol

Conclusions The alkylation of 2,2,6,6-tetramethyl-4-oxopiperidine and 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl enamines gave paramagnetic compounds that contain the pyran ring.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1668–1670, July, 1978.     

异丙肾上腺素与MnO-4的显色反应

报道了新显色剂异丙肾上腺素与MnO-4进行显色反应的最佳条件、灵敏度、选择性和界限比.建立了微量MnO-4的简便检定新方法,检出限量为0.08μg,稀释限为1∶3.8×106.实验结果表明,在pH=9.91的缓冲溶液中,最大吸收波长483.6nm处,MnO-4浓度在1.0～5.0μg/10mL范围内服从比耳定律,表观摩尔吸光系数为 1.8×105.