EFFECT OF MAGNESIUM COMPLEXATION ON THE 31P MIDDLE-GROUP CHEMICAL SHIFTS OF CHAIN AND RING PHOSPHATES

Abstract

For pure sodium polyphosphates, Na _{n + 2}P _n O_{3n + 1}, exhibiting 3 through 6 phosphorus atoms per molecule, the ³¹P chemical shift of the middle group phosphorus atoms as measured in aqueous solution (0.1 M in P) at pH 7 was seen to increase with increasing magnesium ion concentration until there was one Mg atom per polyphosphate molecule, after which the chemical shift decreased. Finally the rate of decrease diminishes and precipitation occurs. For the longer-chain phosphates, Na _{n + 2}P _n O_{3n + 1} with n = 8, 9, 10, or an average of 100, as well as for the ring phosphates, Na _n P _n O_3n for n ranging from 3 through 10, an increase in magnesium concentration simply leads to a decrease in chemical shift which diminishes at the higher concentrations. These data lend additional support to the concept that polymerized phosphate anions in solution exist in preferred conformations which depend on the nature of the counteraction.     

Electron Spin Resonance Study on Grafting of Tetrafluoroethylene onto Polyethylene

An ESR study has been made on the course of grafting of tetrafluoroethylene onto polyethylene. Alkyl and allyl radicals trapped in the polymers were measured under various grafting conditions. It was observed that alkyl radicals decay very rapidly when monomers are in contact with the irradiated polymer, while allyl radicals decay very slowly even in the presence of monomers as in the decay of radicals in irradiated polymers without monomers. The effect of pre-irradiation temperature on grafting was also studied, and the rate of grafting was found to be much faster for lower pre-irradiation temperatures. From these experimental results it was concluded that alkyl radicals play an important Tole in the initiation reaction of grafting.     

Synthesis of pyrazine-2,3-dicarbonitrile and 1,2,4-triazine-5（4H）-one derivatives from furan-2,3-diones

The reaction of furan-2,3-diones with S-methylisothiosemicarbazide hydroiodide yielded novel 1,2,4- triazine-5（4H）-ones, and reaction of furan-2,3-diones with diaminomaleonitrile led to the formation of pyrazine-2,3-dicarbonitrile derivatives, and the hydrolysis of these products led to the formation of more new pyrazine-2,3-dicarbonitrile derivatives. These compounds are potential herbicides and pesticides.     

Preparation of novel chelating sponge as an adsorbent for the removal of Cu~（2＋） from water

The novel chelating sponge modifed with hydroxamic acid groups was prepared by a grafting polymerization followed by a nucleophilic substitution reaction.Elementary analysis,SEM,FT-IR spectroscopy and XPS were used to characterize the spongy adsorbent（PVA-MA-HH）.Adsorption isotherm study indicated that PVA-MA-HH had high equilibrium adsorption capacity for Cu2＋.     

An efficient,rapid and facile procedure for conversion of aldoximes to nitriles using triphenylphosphine and N-halo sulfonamides

N,N,N＇,N＇-Tetrabromobenzene-1,3-disulfonamide （TBBDA）/triphenylphosphine and N,N,N＇,N＇-tetra- chlorobenzene-1,3-disulfonamide （TCBDA）/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature.     

四氯合钴(Ⅱ)-4-氯苄基吡啶季铵盐的制备及其晶体结构和抗菌性能

合成了1种含四氯合钴配阴离子的4-氯苄基吡啶季铵盐[4-ClBzPy]2[CoCl4];利用元素分析仪、X射线单晶衍射仪以及紫外光谱仪和红外光谱仪等分析了其组成、晶体结构及光谱学性质;利用电导仪测定了[4-ClBzPy]2[CoCl4]的电导,并检测了其对金黄色葡萄球菌和大肠杆菌的抗菌活性.结果表明,合成的[4-ClBzPy]2[CoCl4]季铵盐为单斜晶系,P2(1)/c空间群,晶胞参数为a=0.769 5(13)nm,b=1.895 1(3)nm,c=0.946 3(15)nm,β=93.183(2)°,V=1.378 0(4)nm3,Z=2,Dc=1.470g/cm3,GOOF=1.007,R1=0.041 8,wR2=0.100 2.与此同时,季铵盐[4-ClBzPy]2[CoCl4]对金黄色葡萄球菌和大肠杆菌均具有较好的抗菌活性.     

两种含大吸电子取代基的SnR_2Cl_2化合物的合成和晶体结构

以SnCl4和2,4,6-(CF3)3C6H2Li、2,6-(CF3)2C6H3Li为原料合成了两种含大吸电子取代基的化合物Sn[2,4,6-(CF3)3C6H2]2Cl2(缩写为SnAr2Cl2)和Sn[2,6-(CF3)2C6H3]2Cl2(缩写为Sn Ar′2Cl2),利用X射线衍射仪和核磁共振谱仪(19F NMR)表征了产物SnAr2Cl2和SnAr′2Cl2的晶体结构.     

方便面中砷元素的形态分析

建立了硝酸提取,高效液相色谱一原子荧光联用技术测定方便面中不同砷形态的分析方法。样品经0．15mol／L盐酸溶液超声提取后离心过滤,上机测试。实验表明：砷的4种形态亚砷酸[As（Ⅲ）]、砷酸[As（V）]、一甲基胂酸（MMA）和二甲基胂酸（DMA）的线性范围为0-50μg／L,相关系数（r）均优于0．9990,检出限在2～8μg／L之间,砷各形态的测量重复性（以RSD表示）均小于5％,样品的加标回收率为78％-118％。同时用原子荧光光度计检测了样品中总砷,并将两种方法测定结果进行了对比,结果符合理论以及文献报道。该方法操作简单快速、结果准确可靠,适用于方便面中砷形态的分析测定。     

卟啉单晶微纳米棒的合成及光电性能研究

通过相界面反应制备了一维卟啉微纳米棒,并通过紫外、红外和X衍射仪等多种表征方法对其进行了表征.结果表明,在无机酸的作用下,卟啉分子通过-,氢键和静电作用等多种相互作用聚集成有序的J-聚集体.将此一维卟啉微纳米棒构筑为微纳米器件,并测试其光电性能.该纳米器件在可见光照射下的光电流很大,关闭光源,电流在40 s内降到最低,再次打开光源,电流又在120 s内升到了最大.经过多次＂开＂、＂关＂光源,电导的光响应依旧没有降低.这种具有光电响应的卟啉微纳米棒有望成为微纳电子器件的光电元件.     

含吡啶基团的双极主体材料的合成、性能与蓝光电致磷光器件研究

吡啶类衍生物具有较好的电子传输性能和较高的三线态能级,在有机电致发光中一般用来构建电子传输材料或主体材料中的电子传输单元.本文通过将吡啶的2,6位与三苯胺或N-苯基-咔唑的邻位连接设计合成了两个基于吡啶的双极主体材料DTPAPPy和DCzPPy.它们的三线态能级分别为2.64和2.70eV.以它们作为主体材料制备的基于Firpic的蓝光磷光器件最大电流效率分别为15.4和25.3cd/A.