2-甲基-2-丁醇的低温热容和热力学性质

本文用精密自动绝热量热仪测定了2-甲基-2-丁醇在80～305 K温区的热容,从热容曲线(Cp-T) 发现三个固－固相变和一个固－液相变, 其相变温度分别为T = 146.355, 149.929, 214.395, 262.706 K。从实验热容数据用最小二乘法得到以下四个温区的热容拟合方程。在80～140K温区, Cp,m = 39.208 + 8.0724X - 1.9583X2 + 10.06X3 + 1.799X4 - 7.2778X5 + 1.4919X6, 折合温度X = (T –110) / 30; 在 155 ～ 210 K温区, Cp,m = 70.701 + 10.631X + 12.767X2 + 0.3583X3 - 22.272X4 - 0.417X5 + 12.055X6, X = (T –182.5) /27.5; 在220 ～ 250 K温区, Cp,m = 99.176 + 7.7199X - 26.138X2 + 28.949X3 + 0.7599X4 - 25.823X5 + 21.131X6, X = (T – 235)/15; 在 270～305 K温区, Cp,m =121.73 + 16.53 X- 1.0732X2 - 34.937X3 - 19.865X4 + 24.324X5 + 18.544X6, X = (T –287.5)/17.5。从实验热容计算出相变焓分别为0.9392, 1.541, 0.6646, 2.239 kJ×mol-1; 相变熵分别为6.417, 10.28, 3.100, 8.527 J×K-1×mol-1。根据热力学函数关系式计算出80～305 K温区每隔5 K的热力学函数值 [HT –H298.15]和 [ST –S298.15]。     

一种新颖的二维4f-3d-5d多金属-异烟酸配合物的合成、晶体结构和磁性研究

通过水热方法合成了一种新颖的异金属金属-异烟酸无机-有机杂化体[Zn0.5(H2O)]{(Hg2Cl5)[Er(C6NO2H4)3(H2O)2]}(HgCl2)·0.5CH3OH·0.5H2O (1)并对其进行了单晶X-射线衍射结构表征。该化合物是首例4f-3d-5d多金属-异烟酸配合物。化合物1属于单斜晶系C2/c空间群,每个单胞中有8个分子,晶体学参数为：a = 34.165(4) Å,b = 9.4692(8) Å,c = 24.575(3) Å,β = 115.090(5)°,V = 7200(1) Å3,C18.50H21Cl7ErHg3N3O10Zn0.50,Mr = 1495.25,Dc = 2.759 g/cm3,T = 293(2) K,μ(MoKα) = 15.954 mm-1,F(000) = 5400, R1/wR2 = 0.0561/0.0909,共有6468个独立衍射点,其中[I > 2σ(I)]的有3157个。该化合物具有新颖的二维{(Hg2Cl5)[Er(C6NO2H4)3(H2O)2]}层状结构,由Hg2Cl5–连接[Er(C6NO2H4)3(H2O)2]链形成。该二维层和氯化汞及结晶水之间通过氢键形成三维结构,甲醇分子和水合锌离子位于该三维结构的空隙中。对化合物1的磁性测试显示该化合物具有反铁磁作用。     

钯（II）-克林霉素-卤代荧光素体系的共振瑞丽散射光谱及其分析应用

在pH为5.0-5.4的乙酸-乙酸钠缓冲溶液中,克林霉素（Clin）与钯(Ⅱ)形成螯合阳离子,它能进一步与二碘荧光素（DIF）,赤藓红（Ery）,曙红Y（EY）等卤代荧光素类染料反应形成1：1：1的三元离子缔合物,此时将引起吸收光谱变化和荧光猝灭,同时还导致共振瑞利散射(RRS)的急剧增强并产生新的RRS光谱,钯(Ⅱ)-克林霉素与DIF,Ery和EY形成产物的最大散射波长分别位于285,287,32 1nm处,另外还有些较弱的散射峰存在。散射增强（ΔI）与克林霉素浓度在一定范围内成正比,可用于克林霉素的定量测定。对于DIF,Ery和EY体系的线性范围和检出限分别为0.025-2.1μg•mL-1和7.8 ng•mL-1,0.053-2.4μg•mL-1和16.0 ng•mL-1;以及0.038-2.4μg•mL-1和11.0 ng•mL-1。本文研究了适宜的反应条件,考察了共存物质的影响,表明方法有较好的选择性,基于三元离子缔合物的RRS光谱,发展了一种高灵敏、简便快速测定克林霉素的新方法。文中还对离子缔合物的组成,结构和反应机理,以及离子缔合物对吸收,荧光和RRS光谱的影响进行了讨论。     

ECD & CAD裂解方式的FT-ICR-MS研究

傅立叶变换离子回旋共振质谱(Fourier transform ion cyclotron resonance mass spectrometry,FTICR-MS),具有经典质谱及现代质谱技术的多种功能,由于采用离子回旋共振质量检测器,FT-ICR-MS具有超高分辨率、超高灵敏度(fmol),以及较宽的质量范围(m/z＞10 000 u).多级质谱功能与肽库配合越来越广泛地应用到生物大分子的研究中[1-2],已经成为生命科学相关前沿领域如蛋白质组研究不可缺少的工具之一.     

Protein surface recognition of the novel tetra-carboxylphenyl calix[4]arene to cytochrome c

The interaction of the novel tetra-carboxylphenyl calix[4]arene （TCPC） with the bovine heart cytochrome c （Cc） was first investigated by fluorescence spectroscopy and molecular modeling methods. The formation of a stable 1：1 complex was monitored by fluorescence titration, and its binding constant is 1.916 ×10^7 L mol^-1. Molecular modeling reveals the recognition mechanism of TCPC to the Cc surface, that is, the electrostatic interaction drives TCPC to the Cc surface, and the van der Waals interaction orientates TCPC parallel to the cleft of Cc.     

流通池光度滴定法应用—络合反应中的质子释放数测定

用具有流通池的分光光度计作测定装置,建立了由平衡移动法测定络合反应中质子释放数的新方法。方法简单、快速,仅用一个标准溶液,适于在变更pH值范围内金属离子不发生水解和没有其他副反应的体系。     

Catalytic Asymmetric Construction of α‐Quaternary Cyclopentanones and Its Application to the Syntheses of (−)‐1,14‐Herbertenediol and (−)‐Aphanorphine

A novel and efficient strategy to build α‐benzylic quaternary cyclopentanones with excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 % yield) has been developed, and its application demonstrated by the first catalytic asymmetric total synthesis of (?)‐1,14‐herbertenediol and the formal synthesis of (?)‐aphanorphine.     

Motion‐Based,High‐Yielding,and Fast Separation of Different Charged Organics in Water

We report a self‐propelled Janus silica micromotor as a motion‐based analytical method for achieving fast target separation of polyelectrolyte microcapsules, enriching different charged organics with low molecular weights in water. The self‐propelled Janus silica micromotor catalytically decomposes a hydrogen peroxide fuel and moves along the direction of the catalyst face at a speed of 126.3 μm s^?1. Biotin‐functionalized Janus micromotors can specifically capture and rapidly transport streptavidin‐modified polyelectrolyte multilayer capsules, which could effectively enrich and separate different charged organics in water. The interior of the polyelectrolyte multilayer microcapsules were filled with a strong charged polyelectrolyte, and thus a Donnan equilibrium is favorable between the inner solution within the capsules and the bulk solution to entrap oppositely charged organics in water. The integration of these self‐propelled Janus silica micromotors and polyelectrolyte multilayer capsules into a lab‐on‐chip device that enables the separation and analysis of charged organics could be attractive for a diverse range of applications.     

Electrochemical Sensors Using Two‐Dimensional Layered Nanomaterials

Two‐dimensional (2D) layered nanomaterials, e.g. graphene and molybdenum disulfide (MoS₂), have rapidly emerged in material sciences due to their unique physical, chemical and mechanical properties. In the meanwhile, there is a growing interest in constructing electrochemical sensors for a wide range of chemical and biological molecules by using these 2D nanomaterials. In this review, we summarize recent advances on using graphene and MoS₂ for the development of electrochemical sensors for small molecules, proteins, nucleic acids and cells detection. We also provide our perspectives in this rapidly developing field.