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141.
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.  相似文献   
142.
A series of PCL/MDI/BDO segmented polyurethanes have been synthesized by two-step method in solution.The hard segment content ranges from 10% to 48% by weight, and the molecular weight of PCL diols is 1500. Hard segment spherulites have been observed in compression molded specimens of all of the samples except the one of the lowest hard segment content. The difficulty in sphernlite formation was explained as only in a small temperature range,the microphase separation rate may be faster than the crystallization rate and all these processes are very slow due to the hydrogen bonding between hard and soft segments and the interactions between hard segments themselves. PCL soft segments of molecular weight 1500 is still crystallizable and may form different crystalline superstructures.  相似文献   
143.
1 INTRODUCTION Transition metal complexes bridged by 1, 2, 4-triazole group can produce interesting structures and specific properties[1]. Many attempts have been made to synthesize a variety of complexes with paramagnetic centers by using such ligands, and their structures and magnetic properties have been characterized[2]. However, the polynuclear Ag(I) complexes bridged by 1, 2, 4-triazole have been poorly studied[3]. Recently, we have prepared a series of silver(I) triazole complex…  相似文献   
144.
范玉华  郝锐  毕彩丰  马玉祥 《合成化学》2003,11(3):230-232,236
合成了稀土硝酸盐与希夫碱盐2-羟基-1-萘醛缩蛋氨酸钾(以KL表示)及邻菲咯啉(Phen)的四种固体三元配合物。通过元素分析,IR,UV,DTA-TG及摩尔电导分析等手段确定配合物的组成为[Ln(L)(Phen)(NO3)(H2O)]NO3(Ln=Gd,Dy,Er,Yb),并对它们的配合方式及某些物理和化学性质进行了研究。  相似文献   
145.
Intrinsic viscosities, [η], second virial coefficients, A2, and preferential solvation coefficients, λ, for the ternary systems n-alkane (l)-butanone (2)-poly(dimethylsiloxane) (PDMS) (3), with n-alkane = n-hexane, n-heptane, n-nonane and n-undecane, have been determined at 20°. The K and a constants of the Mark-Houwink equation have been evaluated over the whole composition range of the binary solvent mixtures. Polymer (mixed solvent) interaction parameters and unperturbed dimensions have been evaluated both from A2 and [η] data, the feasibility of A2 evaluation from [η] experimental data or vice versa being discussed. Experimental and calculated (through Dondos and Patterson theory) excess free energies, GE, follow similar trends with composition; large numerical discrepancies, however, arise between both sets of GE. Maxima in [η], in a and in A2 are accompanied by inversion points in λ. The solvent mixture composition range in which PDMS is preferentially solvated by n-alkane, as well as the extent of solvation, decrease with increasing number of carbon atoms in the n-alkane.  相似文献   
146.
马忠龙  张伦  刘昌俊 《催化学报》2003,24(9):645-646
Hydrogenperoxideisagreenoxidantwithgreatpotentialformuchapplication .Thepresentproduc tionofhydrogen peroxiderequiressevereconditionsand generates pollutants .AlternativesynthesesarerequiredandthesynthesisofH2 O2 fromCO ,H2 OandO2 isverypromising .AsshowninEq(1) ,thesynthesisisthermodynamicallyfavored :CO +H2 O +O2 H2 O2 +CO2 (1)ΔG02 98=- 134kJ/mol  ThereactionwasfirstreportedbyZudinetal[1]whousedpalladiumtriphenylphosphaneasacatalyst.Bianchietal[2 ] usedabiphasesystemforthesynthe …  相似文献   
147.
A soluble poly(meta-phenylene)derivative with rigid twisted biphenyl unit was synthesized by the Yamamoto coupling reaction.The polymer is soluble in common organic solvents,and the number-average molecular weight is about 6500.The UV-Vis and quantum chemical calculation indicate that the different conformation segments named "conformers" exist in the polymer backbones;it was also further confirmed by the single crystal X-ray diffraction study of the dimeric model compound.The π-π transition of biphenyl segments of twisted and planar conformations made the polymer exhibit a strong absorption around 256 nm and a weak absorption at about 300 nm.Furthermore,the polymer exhibits a strong UV photoluminescence at 372 nm when the excitation wavelengths are longer than 300 nm.The ultraviolet-emitting electroluminescence(EL)device with the single layer structure shows EL λmax of the derivative at 370 nm.  相似文献   
148.
A novel coordination polymer {[Zn(ts-gln)(bipy)]3H2O}n (ts-glnH2=N-p-toly-sulfonyl-glutamine,bipy=2,2-bipyridine) has been prepared and structurally characterized by X-ray diffraction method. It crystallizes in orthorhombic,space group P212121 with a=8.2622(5),b=16.6244(10),c=18.2807(10) ,V=2510.9(3) 3,C22H28N4O8SZn,Mr=573.91,Z=4,Dc= 1.518 g/cm3,μ(MoKa)=1.115 mm-1,F(000)=1192,the final R=0.0262 and wR=0.0662 for 5691 independent reflections with Rint=0.0240. The zinc(Ⅱ) atom is coordinated by N(3) and N(4) atoms of a bipy molecule,two carboxylate O(1) and O(2A) and amino N(1) atoms of ts-gln ligands,resulting in a square-pyramidal geometry. The title complex consists of an infinite zigzag chain of zinc(Ⅱ) ions linked by the carboxylate of N-p-tolysulfonyl-glutamine.  相似文献   
149.
1 INTRODUCTION Cadmium (Ⅱ) complexes have been exten- sively studied from both chemical and structural views, mainly due to the capability of cadmium (Ⅱ) (shared by most d10 metal ions) to adopt different modes of coordination determined by the consideration of size, as well as electrostatic and covalent bonding forces[1]. And the field of coordination polymers has witnessed tremendous growth over the last decade[2]. Many coordination polymeric networks have been shown to posses intere…  相似文献   
150.
用二步法合成了不同软段 (PPO ,PEG ,PEPA)聚氨酯 酰亚胺 (PUI)嵌段共聚物 ,FTIR光谱表征了所有合成PUI分子主链均含有酰亚胺链段 ,并研究了PUI嵌段共聚物的热性能受软段类型及长度的影响 .DSC研究表明聚酯型PUI的软硬段之间的相容性比聚醚型PUI好 ,随相同软段分子量的增加 ,PUI体系的软硬段兼容性变差 ,并显示了相分离的特征 ;热失重 (TGA)研究得出不同软段的PUI样品的热稳定性大小顺序为 :PEPA PUI >PEG PUI>PPO PUI ;动态力学 (DMTA)研究给出了所合成的PUI样品在 5 0~ 2 0 0℃范围内均出现了较长的模量平台显示出有较好的耐热性 ,且随硬段含量的升高其储能模量不断增强  相似文献   
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