Synthesis,Structures, and Fluorescent Properties of Three Cobalt‐Based Coordination Polymers with a Rigid Tripodal Carboxylate Ligand

Three cobalt(II) coordination polymers, [Co₂(tatb)₂(2,2′‐bipy)₂ (H₂O)₂ · DMA · 2H₂O] ( 1 ), [Co₂(tatb)₂(1,10‐phen)₂(H₂O)₂ · 2H₂O] ( 2 ) and [Co(tatb)(1,3‐dpp) · H₂O] ( 3 ) (H₃tatb = 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)tribenzoic acid; 2,2′‐bipy = 2,2′‐bipyridyl; 1,10‐phen = 1,10‐phenanthroline; 1,3‐dpp = 1,3‐bis(pyridin‐4‐yl)propane), were synthesized solvothermally and characterized by single‐crystal and powder X‐ray diffraction (PXRD), as well as IR spectroscopy. Complexes 1 and 2 exhibit 1D double‐chain structures, which further connect into interesting 3D networks by hydrogen bond and strong π–π interactions. Complex 3 possesses 2D 4⁴‐sql topology, which is packed parallel in an AA fashion. Moreover, thermal stability properties and photoluminescence properties of 1 , 2 and 3 were also investigated.     

粉末压片—X射线荧光光谱法测定土壤中的铜铅锌砷锑钴铬镍等重金属元素

采用粉末压片法制样,使用ZSX PrimusⅡ型X射线荧光光谱仪,对土壤样品中与生命健康和环境污染有直接影响的重金属元素Cu、Pb、Zn、As、Sb、Co、Cr、Ni进行同时测定.选用土壤国家标准物质、以国家标准物质为基体自制校准物质绘制标准曲线,解决了相关标准不足的问题,拓宽了元素测定范围(10~20 000μg/g),重点探讨了As、Sb的测量条件.虽然As、Sb的检出限和准确测定下限较高,但对于土壤质量的评价有重要的参考意义.方法快速、简便、准确.     

光电功能配合物研究进展

南京大学游效曾院士等在国家自然科学基金重点项目的连续资助下 ,以联系高技术的分子电磁性质和非线性光学性质的化学研究为突破口 ,在光电功能分子导电配合物、非线性光学配合物和磁性配合物方面取得重要进展 ,并使我国在该领域中的工作在国际上取得一定地位。1 .分子导电配合物研究了分子间距接近范氏半径之和的中性二硫烯导电配合物 ,这类化合物在实践中有重要意义 ;设计制备了新型杂多酸的二硫烯自由基无机 /有机杂化配合物 ,可望兼有导电和非线性光学性能双重功能 ;发展了一种新的方便的全共轭双金属配合物( Bu4 N) 2 tto[Ni( dmit) …     

壳聚糖及其衍生物与金属配位的研究进展

本文综述了壳聚糖、壳聚糖衍生物及其降解产物与金属配位的性能,形成某些配位化合物的条件、组成、结构及其表征,阐述了它们的应用。     

新型膦配体PDBPDS在氢甲酰化反应中催化剂配体性能的研究

用量子化学 AMI方法优化了 1 -苯基二苯并膦二磺化产物 ( PDBPDS)和三磺化三苯基膦 ( TPPTS)的几何构型 .比较两种化合物的空间结构和电子结构发现 ,在氢甲酰化铑膦催化反应体系中 ,PDBPDS的配体性能优于 TPPTS.首次研究了以 PDBPDS为配体的铑膦催化剂对丙烯氢甲酰化反应的催化性能 ,考察了反应温度、压力、膦铑物质的量比和搅拌速度对催化活性和选择性的影响 .结果表明 ,在 2 .0 MPa,1 0 0℃ ,膦铑物质的量比为 35 ,搅拌速度为 5 0 0 r/min及 V( H2 ) /V( CO) =1 /1的条件下 ,催化活性可达到 2 80 0 g(丁醛 ) /[g(铑 )·h],正异构产物物质的量比为 1 2 .3,在相同条件下与传统的三磺化三苯基膦 ( TPPTS)为配体的铑膦催化剂相比 ,催化活性和选择性提高了 2倍 .反应结束后 ,有机相和水相分离简单 ,有机相铑浓度仅为3.6× 1 0 - 8mol/L,有效地解决了铑流失问题 ,表明 PDBPDS是极具开发前景的新型水溶性配体     

新铌酸盐Ba5NdTi3Nb7O30的合成与介电性能

The New Niobate Ba₅NdTi₃Nb₇O₃₀ was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba₅NdTi₃Nb₇O₃₀ were determined by X-ray powder diffraction and dielectric measurements. The results show that Ba₅NdTi₃Nb₇O₃₀ belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm^-3. Ba₅NdTi₃Nb₇O₃₀ belongs to relaxor ferroelectrics. The phase transition temperature (T_c) of Ba₅NdTi₃Nb₇O₃₀ from ferroelectric to paraelectric is found to shift toward higher temperature side at higher fre-quency, and T_c is 90℃ at 1kHz. At room temperature, the dielectric constant (ε_r) and dielectric loss of Ba₅NdTi₃Nb₇O₃₀ decrease with the increase of frequency, and Ba₅NdTi₃Nb₇O₃₀ ceramic have high dielectric constant 489 at 1kHz.     

改性Y分子筛的酸碱性能及吸附性能的研究

吡啶、吡咯、苯、甲苯、乙苯作为探针分子，在Li＋, Na＋, K＋, Cs＋改性的Y型分子筛上进行吸附，用TPD及IR方法系统地研究了不同碱金属离子改性的Y型分子筛的酸碱性能和吸附性能的变化. 结果表明，按Li、Na、K、Cs的顺序, 随着碱金属离子半径的增大, 其L酸酸强度依次减弱，L碱的强度逐渐增强.由于改性Y型分子筛所含碱金属离子的不同，其对芳烃的吸附的强弱及吸附量的大小亦不同.随着骨架外的阳离子的半径逐渐增大，碱的强度逐渐增强，与芳烃的作用愈强烈，导致TPD脱附峰温增高及芳烃和侧链上的C－H伸缩振动谱带向低波数位移愈多.由于位阻的原因，对含同一种碱金属离子的分子筛来说，随着芳烃侧链C数的增加，芳烃的吸附量逐渐减小.     

电解液对LiCr0.1Mn1.9O4电化学性能的影响

容量;循环特性;自放电;电解液对LiCr0.1Mn1.9O4电化学性能的影响     

Adiabatic calorimetry and thermal analysis on acetaminophen

Molar heat capacities of acetaminophen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 330 K. A solid-solid transition at 149.96 K was found from the C_p,m-T curve. The polynomial functions of C_p,.m(J K^-1 mol^-1) vs. T were established on the heat capacity measurements by means of the least square fitting method. Thermal decomposition processes of acetaminophen have been studied by thermogravimetry. And the thermal decomposition kinetics parameters, such as activation energy E, pre-exponential factor A and reaction order n, were calculated by TG-DTG techniques with the Freeman-Carroll method, Kissinger method and Ozawa method. Accordingly the thermal decomposition kinetics equation of acetaminophen is expressed as: dα/dt=2.67·10⁷e^-89630/RT(1-α)^0.23. The process of fusion has been investigated through DSC. The melting point, molar enthalpy and entropy of fusion are to be (441.89±0.04) K, 26.49±0.44 kJ mol^-1 and 59.80±1.01 J K^-1 mol^-1, respectively.