Two cobalt(II) 5-aminoisophthalate complexes and their stable supramolecular microporous frameworks

Two stable supramolecular microporous cobalt(II) polymers, namely [Co(HAIP)2]n.3nH2O (1) and [Co(AIP)(H2O)]n (2), AIP = 5-aminoisophthalate, were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, IR spectra, thermogravimetric analyses, and variable-temperature magnetic susceptibility measurements. The two complexes are constructed from the same Co2(CO2)2 SBU, which is extended into a 1D chain in 1 and a 2D layer in 2. As a result, 1 and 2 are 2D and 3D coordination polymers, respectively. The 3D supramolecular network of complex 1 is held up by strong hydrogen bonds formed between carboxylate groups and shows very high stability when the free H2O molecules are removed, indicating an extraordinarily stable H-bonding system. Upon water ligands being liberated, complex 2 becomes a stable microporous solid with coordination-unsaturated Co centers. The behavior of the susceptibility curve of 1 suggests the occurrence of an interesting intrachain antiferromagnetic coupling between the Co(II) ions and the presence of a significant orbital contribution, whereas the features of 2 indicate an antiferromagnetic coupling with T(N) = 3.5 K and a long-range antiferromagnetic order with a field-induced magnetic transition.     

MILD煤粉燃烧湍流与化学反应相互作用的数值分析

采用计算流体动力学(CFD)数值模拟方法分析了湍流与化学反应相互作用下MILD煤粉燃烧的微观特征。比较了涡耗散模型(EDM模型)和涡耗散概念模型(EDC模型)对MILD煤粉燃烧的影响,两者得到的速度场、温度场、烟气成分等结果与实验结果符合较好.在此基础上分析了MILD煤粉燃烧湍流和化学反应的微观特征尺度,发现采用EDC模型能更准确地反映MILD煤粉燃烧的微观特征,即山于强烈的烟气内部再循环导致的高湍流混合和烟气稀释后低氧浓度下的缓慢化学反应.     

A Three-dimensional Neodymium(III)-potassium(I) Coordination Polymer

The title compound [NdK(btec)(H2O)2]n 1 was synthesized via the hydrothermal reaction of Zn(OAc)2·H2O, Nd(NO3)3 and KOH with 1,2,4,5-benzenetetra-carboxylic acid (H4btec), and characterized by elemental analysis and infrared spectra.The crystal of 1 crystallizes in monoclinic, space group P21/c with a = 8.9023(3), b = 7.8954(1), c = 17.6249(5)A, β = 91.857(1)o, V = 1238.16(6) -3, Z = 4, C10H6KNdO10, Mr = 469.49, Dc = 2.519 g/cm3, F(000) = 900 and μ(MoKα) = 4.585 mm-1.The final R = 0.0404 and wR = 0.0832 for 2197 observed reflections with I > 2σ(I) and R = 0.0431 and wR = 0.0854 for all data.X-ray diffraction reveals that the btec ligand serves as a (16-bridging ligand to link the Nd(III) and K(I) atoms into a three-dimensional coordination polymer.Photoluminescent investigation shows that the title compound displays strong emission in the blue region, which may be attributed to an intraligand emission state.     

Preparation of Porous Polylactide Microspheres and Their Application in Tissue Engineering

In this study,porous polylactide (PLA) microspheres with different structures were prepared through the multiple emulsion solvent evaporation method.By changing organic solvents (ethyl acetate and chloroform) and adding effervescent salt NH4HCO3 in the inner water phase,microspheres with porous capsular,matrix,microcapsular and multivesicular structures were prepared.The protein encapsulation and release,and the cell growth behavior of porous microspheres were further explored.Under the same inner water phase,microspheres prepared with chloroform had higher protein encapsulation efficiency and less protein release rate as compared with those prepared with ethyl acetate.Cell experiments showed that the relatively rough surface of microspheres prepared with chloroform was more favorable for the cell growth in comparison with the smooth surface of microspheres prepared with ethyl acetate.This study shows a simple and effective method to control the protein release and cell growth behaviors of polymer microspheres by tuning their porous structure.     

新型含氟液晶类化合物的质谱研究

本文报道66个新型含氟液晶类化合物的电子轰击电离质谱(EIMS). 66个化合物分为三个类型, 即炔醚类, 炔酯类和炔类. 并利用MS/MS联用技术和高分辨质谱(HRMS)数据研究了三种不同类型化合物的裂解机理, 并总结其规律性, 结果将有助于未知的类似化合物的结构鉴定 .     

CdS纳米晶与多肽相互作用研究

研究了半导体CdS纳米晶的表面功能化及荧光光谱特性,并利用静电/配位自组装方法实现了多肽和CdS纳米晶的生物无机偶联,研究了纳米晶多肽偶联体系的荧光光谱以及多肽与CdS纳米晶之间的相互作用.结果表明:含巯基多肽对CdS纳米晶表面形成完善包覆,消除CdS纳米晶表面缺陷,使CdS纳米晶荧光增强;含端氨基多肽使CdS纳米晶荧光出现先升后降趋势;其余不含巯基和氨基的多肽均猝灭CdS纳米晶荧光,猝灭机制属于形成化合物所引起的静态猝灭,它们的结合常数约为2×104,结合位点数约为0.87～1.00.     

金属钾和碳酸钠高压合成金刚石

以金属钾和碳酸钠为反应原料, 在压力为2 GPa, 温度为500 ℃的密封白金坩埚中反应18 h, 所得产物通过粉末X射线衍射和显微拉曼分析进行了表征, 证实合成出了微米级的金刚石. 对金刚石的合成机理进行了研究, 推测其反应过程为碳酸钠在铂和钾的作用下分解出CO2, CO2与钾反应得到金刚石. 研究结果表明金刚石可以在温和的条件下合成.     

Ce(III)在辣根体中的迁移

应用放射性同位素示踪法, 即结合放射自显影和液体闪烁器检测及电镜放射自显影技术, 首次定性、定量地研究Ce(III)离子在辣根植物中的迁移. 结果表明: (1) Ce(III)离子能被辣根植物吸收并随时间发生迁移; (2)电镜放射自显影结果显示, Ce(III)离子迁移是通过质外体至共质体进入细胞的. Ce(III)离子在辣根植物体中的行为, 为稀土离子植物环境效应机理及辣根植物安全防护提供借鉴.     

BIC和HA体系的氢键驱动的HOPG表面手性自组装分子动力学模拟

5-（苄氧基）-间苯二甲酸衍生物（BIC）与庚醇（HA）分子在高定向热解石墨（HOPG）表面吸附,通过氢键等弱相互作用会形成具有手性特征的二维网络结构。对该过程进行分子动力学模拟,通过几何结构、能量、氢键数目、氢键键长、氢键键角等特征性参数的定量分析,并与实验结果比照,进行氢键与手性自组装结构的形成趋势和稳定性的相关性研究。     

Amine- and phosphine-free palladium(II)-catalyzed homocoupling reaction of terminal alkynes

An efficient, amine- and phosphine-free palladium(II)-catalyzed homocoupling of terminal alkynes has been developed. In the presence of PdCl₂, CuI, Me₃NO, and NaOAc, homocoupling of various terminal alkynes underwent smoothly to afford the corresponding diynes in moderate to high yields without any phosphine ligands. In contrast, the presence of a phosphine ligand (PPh₃) disfavored this palladium-catalyzed homocoupling procedure. Bases, solvents, and CuI have fundamental influence on the palladium-catalyzed homocoupling of terminal alkynes.