Low-temperature Heat Capacities and Thermodynamic Properties of Hydrated Sodium Cupric Arsenate [NaCuAsO4·1.5H2O（s）]

Low-temperature heat capacities of the solid compound NaCuAsO4·1.5H2O(s)were measured using a precision automated adiabatic calorimeter over a temperature range of T=78 K to T=390 K.A dehydration process occurred in the temperature range of T=368-374 K.The peak temperature of the dehydration was observed to be TD=(371.828±0.146)K by means of the heat-capacity measurement.The molar enthalpy and entropy of the dehydration were ΔDHm=(18.571±0.142)kJ/mol and ΔDSm=(49.946±0.415)J/(K·mol),respectively.The experimental values of heat capacities for the solid(Ⅰ)and the solid-liquid mixture(Ⅱ)were respectively fitted to two polynomial equations by the least square method.The smoothed values of the molar heat capacities and the fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated at an interval of 5 K.     

Low-Temperature Heat Capacities and Thermodynamic Properties of Octahydrated Barium Dihydroxide,Ba（OH）2·8H2O（s）

Low-temperature heat capacities of octahydrated barium dihydroxide, Ba（OH）2·8H2O（s）, were measured by a precision automated adiabatic calorimeter in the temperature range from T=78 to 370 K. An obvious endothermic process took place in the temperature range of 345-356 K. The peak in the heat capacity curve was correspondent to the sum of both the fusion and the first thermal decomposition or dehydration. The experimental molar heat capacifies in the temperature ranges of 78-345 K and 356-369 K were fitted to two polynomials. The peak temperature, molar enthalpy and entropy of the phase change have been determined to be （355.007±0.076） K, （73.506±0.011） kJ·ol^-1 and （207.140±0.074） J·K^-1·mol^-1, respectively, by three series of repeated heat capacity measurements in the temperature region of 298-370 K. The thermodynamic functions, （Hr-H298.15 k ）and （Sr-S298.15k）, of the compound have been calculated by the numerical integral of the two heat-eapacity polynomials. In addition, DSC and TG-DTG techniques were used for the further study of thermal behavior of the compound. The latent heat of the phase change became into a value larger than that of the normal compound because the melfing process of the compound must be accompanied by the thermal decomposition or dehydration of 71-120.     

Low Temperature Heat Capacities and Thermodynamic Properties of Zinc L-Threonate Zn（C4H7O5）2（s） by Adiabatic Calorimetry

Low-temperature heat capacities of the solid compound Zn（C4H7O5）2（s） were measured in a temperature range from 78 to 374 K, with an automated adiabatic calorimeter. A solid-to-solid phase transition occurred in the temperature range of 295？322 K. The peak temperature, the enthalpy, and entropy of the phase transition were determined to be （316.269±1.039） K, （11.194±0.335） kJ？mol-1, and （35.391±0.654） J？K-1？mol-1, respectively. The experimental values of the molar heat capacities in the temperature regions of 78？295 K and 322？374 K were fitted to two polynomial equations of heat capacities（Cp,m） with reduced temperatures（X） and [X = f（T）], with the help of the least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound, relative to that of the standard reference temperature 293.15 K, were calculated on the basis of the fitted polynomials and tabulated with an interval of 5 K. In addition, the possible mechanism of thermal decomposition of the compound was inferred by the result of TG-DTG analysis.     

配合物[Fe(CTS)2]·5SO4·7H2O的热分解动力学

研究了壳聚糖对Fe2+的吸附行为,并进行了条件优化,得到了较为理想的合成产物.通过红外光谱和紫外光谱进行了表征,进而用化学分析、元素分析确定了配合物的组成,并利用TG-DSC分析,采用常用的22种机理函数,对非等温动力学数据进行了线性回归拟合处理,求得了配合物主要分解阶段热动力学最可机理函数和动力学参数(E和A).     

Synthesis and Thermodynamic Properties of MgO·B_2O_3·4H_2O

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅａｒｅｍａｎｙｋｉｎｄｓｏｆｍａｇｎｅｓｉｕｍｂｏｒａｔｅｓ ,ｂｏｔｈｎａｔｕｒａｌａｎｄｓｙｎｔｈｅｔｉｃ .Ａｂｏｒａｔｅｄｏｕｂｌｅｓａｌｔ (2ＭｇＯ·2Ｂ2 Ｏ3 ·ＭｇＣｌ2 · 14Ｈ2 Ｏ)ｎａｍｅｄｃｈｌｏｒｏｐｉｎｎｏｉｔｅｗａｓｏｂ ｔａｉｎｅｄｆｒｏｍｔｈｅｎａｔｕｒａｌｃｏｎｃｅｎｔｒａｔｅｄｓａｌｔｌａｋｅｂｒｉｎｅ .1Ｉｎｏｒｄｅｒｔｏｆｉｎｄｔｈｅｆｏｒｍｉｎｇｒｅｌａｔｉｏｎｂｅｔｗｅｅｎｔｈｅｄｏｕｂｌｅｓａｌｔａｎｄｍａｇｎｅｓｉｕｍ ｂｏｒａ…     

(NH4)11Gd[Gd4Mo29O100(H2O)16]·33H2O杂多化合物在苯酚羟化反应中的催化活性

对苯二酚;过氧化氢;(NH4)11Gd[Gd4Mo29O100(H2O)16]·33H2O杂多化合物在苯酚羟化反应中的催化活性     

[Gd(Gly)3(H2O)2]Cl3·H2O的合成与晶体结构

氯化钆;甘氨酸;固态配合物;[Gd(Gly)3(H2O)2]Cl3·H2O的合成与晶体结构     

配合物Zn(Leu)SO4·O.5H2O的合成与热行为

在水-丙酮溶液中制备了zn(Leu)SO4@0.5H2O的配合物.通过热重和红外分析,研究了它的热分解机理,可分为三步完成.第一阶段配合物的脱水过程在60-180℃,形成Zn(Leu)S04,第二阶段,Zn(Leu)SO4进一步分解为Zn(Leu)SO4@9ZnSO4,随后其在728℃完全分解为ZnO.在不同线性升温5.O,10.0,15.0,20.OK@min-1条件下,用两种积分法和三种微分法研究了题目化合物失去配体过程的非等温动力学,相应过程的表观活化能E为133.78KJ@mol-1,指前因子A为1O8.19s-1,配体失去过程为三维扩散机理控制,并建立了反应过程的动力学方程.     

Low-temperature Heat Capacities and Thermodynamic Properties of Solid State Coordination Compound Zn(nicotinate)_2·H_2O(s)

A novel compound—monohydrated zinc nicotinate was prepared via room temperature solid phase synthesis and ball grinding.FTIR,chemical and elemental analyses and X-ray powder diffraction technique were applied to characterizing the structure and composition of the complex.Low-temperature heat capacities of the solid coordination compound were measured by a precision automated adiabatic calorimeter over a temperature range from 77 to 400 K.A solid-solid phase transition process occurred in a temperature range...     

配合物Zn(His)SO4·H2O(s)的低温热容和热力学性质

通过精密自动绝热热量计测定了配合物Zn(His)SO4*H2O(s)在78～390K温区的摩尔热容,由热容曲线得到其起始脱水温度328.90K;用最小二乘法拟合得到摩尔热容(Cp,m)对温度(T)的多项式方程,并在此基础上计算了它的各种热力学函数.此外,研究了其在惰性气氛下的热分解过程.     

[(CH3)2NH2]3[NSiMo12O40]·2DMF·4H2O的合成和晶体结构

电荷转移盐;[(CH3)2NH2]3[NSiMo12O40]·2DMF·4H2O的合成和晶体结构     

配合物Zn(Met)SO4·H2O(s)的低温热容和标准摩尔生成焓

利用精密自动绝热热量计直接测定了配合物Zn(Met)SO4·H2O(s)在78～370K温区的摩尔热容.通过热容曲线的解析得到该配合物的起始脱水温度为T0=329.50K.将该温区的摩尔热容实验值用最小二乘法拟合得到摩尔热容(Cp,m)对温度(T)的多项式方程,并且在此基础上计算出了它的舒平热容值和各种热力学函数值.依据Hess定律,通过设计热化学循环,选择体积为100cm3、浓度为2mol·L-1的盐酸作为量热溶剂,利用等温环境溶解-反应热量计,测定和推算出该配合物的标准摩尔生成焓为?fHms=-(2069.30±0.74)kJ·mol-1.     

Synthesis, Characterization and Thermochemistry of 2MgO：B2O3：1.5H2O

Introduction　　 2MgO·B2 O3(Mg2 B2 O5)and 2MgO·B2 O3·H2 Omightbepreparedaswhiskermaterials .12MgO·B2 O3·H2 OnamedszaibelyiteisamagnesiumboratemineralwithastructuralformulaofMg2 [B2 O4 (OH) 2 ].2 Itisdifficulttosynthesizethiscompoundinthelaboratory .Recently ,weobtainedasimilarcompound 2MgO·B2 O3·1 5H2 Owhenwetriedtopreparewhiskerof 2MgO·B2 O3·H2 Obythephasetransformationof 2MgO·2B2 O3·MgCl2 ·14H2 OinH3BO3solutionunderhydrothermalcondition .Itishope fultopreparewh…     

Syntheses,Structures and Characterizations of Two Vanadium(V) Complexes:[2-MePyH][V^vO2(C14H9N2O3Br)] and [2-EtPyH][V^VO2(C14H9N2O3Br)]

Two new oxovanadium(V) complexes, [2‐MePyH][V^vO₂(L)] (3) and[2‐EtPyH][V^vO₂,(L)] (4) (salicylaldehyde 5‐bromo salicyloylhydrazone is abbreviated as H₂L; 2‐MePyH is protonated 2‐Mepyridine; 2‐EtPyH presents protonated 2‐Et‐pyridine) were obtained from a reaction of VOSO₄ and H₂L in acetonitrile‐methanol with small quantity of 2‐Me‐pyridine or 2‐Et‐pyridine, and characterized by X‐ray diffraction and spectroscopic methods. Crystal data: [2‐MePyH][VO₂(L)] (3), C₂₀H₁₇N₃O₅BrV, M_r = 510.2, monoclinic, P2₁/n, a = 0.7363(1) nm, 6 = 0.9514(1) nm, c = 2.8594(2) nm, β = 95.305(2)°, Z = 4 and V=1.9946(3) nm³, μ(Mo Kα) = 2.539 mm^?1; [2‐EtPyH][VO₂(L)] (4), C₂₁H₁₉N₃ O₃BrV, M_r = 524.2, triclinic, P1 , a = 0.8051(1) nm, b = 0.9413(1) nm, c = 1.4648(2) nm, α=99.1900(10)°, α = 99.4530(10)°, γ = 104.6670(10)°, Z = 2 and V= 1.0355(2) nm³, μ(Mo Kα) = 2.448 mm^?1, X‐Ray analyses revealed that the crystal structures of 3 and 4 have similar packing modes.     

复合物C2H6·(H2O)2中分子间相互作用的理论研究

在B3LYP/6-311 G**水平上得到C2H6.(H2O)2复合物势能面上四种稳定构型。在相同基组下经MP2电子相关能和基组叠加误差(BSSE)进行单点能量校正,求得单体间相互作用能的大小。结果发现:四种稳定构型都通过CH…O氢键而形成,相应σ(CH)键都出现了较小的收缩,导致伸缩振动发生蓝移,在最稳定的复合物Comp lex2和Comp lex3中,H2O(A)分子的一个H原子与C2H6的两个H原子相对距离较短,并且具有最大的总相互作用能和两个单体AC分子间相互作用能,这说明三个氢原子间存在着较强的相互作用,并对分子的稳定性起着重要作用.     

NH_4Al(SO_4)_2·12H_2O的热分解动力学研究

采用热分析(TG-DTA/DTG)、X射线衍射(XRD)研究了固态物质NH4Al(SO4)2.12H2O在氩气中的热分解过程。热分析结果表明,NH4Al(SO4)2.12H2O在氩气中分5步分解,其质量变化率与理论计算相吻合。XRD结果表明,NH4Al(SO4)2.12H2O热分解的最终产物为Al2O3。用Friedman法对各步分解过程的活化能Ea进行了计算,依此为初始值,采用多元非线性回归法得到各个分解步骤可能的动力学模型和参数。     

Dawson结构杂多化合物[4,4′-bipyH]2H4(P2W18O62)?[4,4′-bipy]1.5?4H2O的水热合成及晶体结构

Dawson结构杂多化合物[4;4′-bipyH]2H4(P2W18O62)?[4;4′-bipy]1.5?4H2O的水热合成及晶体结构;水热合成;联吡啶;Dawson结构;杂多化合物     

Synthesis of Mg5(CO3)4(OH)2·4H2O with Flower-like Microstructure and Its Catalytic Activity for Transesterification of Dimethyl Carbonate with Phenol

A novel flower-like hydrated magnesium carbonate hydroxide,Mg_5(CO_3)_4(OH)_2·4H_2O,with micro-structure composed of individual thin nano-sheets was synthesized using a facile solution route without the use of template or organic surfactant.Reaction time has an important effect on the final morphology of the product.The micro-structure and morphology of Mg_5(CO_3)_4(OH)_2·4H_2O were characterized by means of X-ray diffractometry(XRD),field-emission scanning electron microscopy(FE-SEM).Brunauer-Emmett-Teller(BET)surface areas of the samples were also measured.The probable formation mechanism of flower-like micro-structure was discussed.It was found that Mg_5(CO_3)_4(OH)_2·4H_2O with flower-like micro-structure was a novel and efficient catalyst for the synthesis of diphenyl carbonate(DPC)by transesterification of dimethyl carbonate(DMC)with phenol.     

ZrWⅥ1.7WⅤ0.3O7H0.3(OH)2·2H2O的合成与表征

分别利用微乳液水热法和酸蒸气水热法合成了杂多蓝化合物ZrWⅥ1.7WⅤ0.3O7H0.3(OH)2·2H2O. XRD测定结果表明, 该化合物与ZrMo2O7(OH)2·2H2O具有相同晶体结构类型. 使用Rietveld方法对产物进行了结构精修, 并计算出了键参数和键价. 运用EPR技术测定了该化合物中W的价态, 并利用XPS能谱测定了WⅤ/WⅥ的比例. 利用价键和规则, 指出ZrWⅥ1.7WⅤ0.3O7H0.3(OH)2·2H2O中的W-O3-H0.15存在羟基化现象, 并对杂多蓝化合物的红外吸收光谱进行了指认.     

金属碳笼(Met-Cars)化学反应的理论研究Ⅱ.Ti8C12与H2O,C2H4生成Ti8C12(H2O)8和Ti8C12(C2H4)4反应的ab initio研究

用量子化学从头计算方法,研究了Ti8C12分别与H2O,C2H4作用形成Ti8C12(H2O)8,Ti8C12(C2H4)4的反应.计算结果表明,在Ti8cC12(H2O)8中,电子由H2O向Ti8cC12转移,在Ti8cC12(C2H4)4中,电子由Ti8cC12向C2H4转移.从Ti8cC12生成Ti8cC12(H2O)8能量降低,稳定性增加,生成Ti8cC12(C2H4)4能量升高,稳定性减小.