三元配合物Tm[(C_5H_8NS_2)_3(C_(12)H_8N_2)]的热化学性质研究

在无水乙醇中,用吡咯烷二硫代氨基甲酸铵(APDTC)和1,10-邻菲咯啉(o-phen·H2O)与TmCl3·3.65H2O作用,合成了未见文献报道的三元固态配合物,确定它的组成为Tm[(C5H8NS2)3(C12H8N2)]。用RD496-Ⅲ微量热计测定了298.15K下水合氯化铥及两个配体在无水乙醇中的溶解焓,两个配体醇溶液的混合焓及不同温度下标题化合物液相生成反应的焓变。在实验和计算基础上,得到了液相生成反应的热力学参数(活化焓、活化熵和活化自由能),速率常数和动力学参数(表现活化能、频率因子和反应级数)。通过合理的热化学循环,求得了298.15K时标题化合物的固相生成反应焓变;推导了用该热量计测定固态物质比热容的计算式,并测定了题目配合物298.15K的比热容。用RBC-Ⅱ精密转动弹热量计测定了题目配合物的恒容燃烧热,计算了它们的标准摩尔燃烧焓和标准摩尔生成焓。     

三元配合物La[(C5H8NS2)3(C12H8N2)]生成反应的热动力学

在无水乙醇中, 用吡咯烷二硫代氨基甲酸铵(APDTC)和1,10-邻二氮菲(phen)与LaCl3·3.94H2O作用,合成了未见文献报道的三元固态配合物, 确定它的组成为La[(C5H8NS2)3(C12H8N2)]. X粉末衍射说明它为一新相化合物. IR光谱说明配合物中La3 分别与3个APDTC的6个硫原子双齿配位, 同时与phen的两个氮原子双齿配位, 配位数为8. TG-DTG分析显示其热分解为一步生成1/2La2S3 3C. 用微量热计测定了298.15 K下水合氯化镧及两个配体在无水乙醇中的溶解焓, 两个配体醇溶液的混合焓及不同温度下标题化合物液相生成反应的焓变. 在实验和计算基础上, 得到了液相生成反应的热力学参数 (活化焓、活化熵和活化自由能)和动力学参数(速率常数、表观活化能、频率因子和反应级数), 通过合理的热化学循环, 求得了标题化合物的固相反应焓变.     

三元配合物Tm[(C5/sub>H8NS2)3(C12H8N2)]的热化学性质研究

在无水乙醇中，用吡咯烷二硫代氨基甲酸铵(APDTC)和1,10-邻菲咯啉(o-phen·H₂O)与TmCl₃·3.65H₂O作用，合成了未见文献报道的三元固态配合物，确定它的组成为Tm[(C_{5/sub>H8NS2)3(C12H8N2)]。 用RD496-Ⅲ微量热计测定了298.15 K下水合氯化铥及两个配体在无水乙醇中的溶解焓，两个配体醇溶液的混合焓及不同温度下标题化合物液相生成反应的焓变。在实验和计算基础上，得到了液相生成反应的热力学参数(活化焓、活化熵和活化自由能)，速率常数和动力学参数(表现活化能、频率因子和反应级数)。通过合理的热化学循环，求得了298.15 K时标题化合物的固相生成反应焓变；推导了用该热量计测定固态物质比热容的计算式，并测定了题目配合物298.15 K的比热容。用RBC-Ⅱ精密转动弹热量计测定了题目配合物的恒容燃烧热， 计算了它们的标准摩尔燃烧焓和标准摩尔生成焓。}     

三元配合物RE(Et2dtc)3(phen)热化学性质的规律性

在无水乙醇中, 用铜试剂(NaEt₂dtc•3H₂O)和邻菲咯啉(o-phen•H₂O)分别与13种低水合氯化稀土合成了三元固态配合物(其中5种尚未见文献报道), 确定它们的组成可用通式RE(Et₂dtc)₃(phen)表示. IR光谱表明配合物中RE³⁺与3个NaEt₂dtc中的6个硫原子双齿配位, 同时与o-phen中的2个氮原子双齿配位. 用RD496-Ⅲ微量热计测定了298.15 K下13种水合氯化稀土盐及两个配体在无水乙醇中的溶解焓, 两个配体醇溶液的混合焓及13种化合物液相生成反应的焓变, 并通过合理的热化学循环, 求得了标题配合物的固相生成反应焓变; 测定了标题配合物298.15 K的比热容. 用RBC-II精密转动弹热量计测定了标题配合物的恒容燃烧热, 计算了它们的标准摩尔燃烧焓和标准摩尔生成焓. 发现系列配合物RE(Et₂dtc)₃(phen) (RE＝La, Pr, Nd, Sm～Lu)的多项热化学性质, 如低水合氯化稀土盐在无水乙醇中的溶解焓以及配合物的液相生成反应焓变和固相生成反应焓变、常温比热容、标准摩尔燃烧焓和标准摩尔生成焓都与稀土原子序数作图呈现“三分组现象”. 较集中地反映出配合物中RE³⁺与配体间的化学键有一定程度的共价性, 这是由于稀土离子5s²5p⁶轨道对4f电子的不完全屏蔽引起的.     

三元配合物RE(Et2dtc)3(phen)热化学性质的规律性

在无水乙醇中, 用铜试剂(NaEt₂dtc•3H₂O)和邻菲咯啉(o-phen•H₂O)分别与13种低水合氯化稀土合成了三元固态配合物(其中5种尚未见文献报道), 确定它们的组成可用通式RE(Et₂dtc)₃(phen)表示. IR光谱表明配合物中RE³⁺与3个NaEt₂dtc中的6个硫原子双齿配位, 同时与o-phen中的2个氮原子双齿配位. 用RD496-Ⅲ微量热计测定了298.15 K下13种水合氯化稀土盐及两个配体在无水乙醇中的溶解焓, 两个配体醇溶液的混合焓及13种化合物液相生成反应的焓变, 并通过合理的热化学循环, 求得了标题配合物的固相生成反应焓变; 测定了标题配合物298.15 K的比热容. 用RBC-II精密转动弹热量计测定了标题配合物的恒容燃烧热, 计算了它们的标准摩尔燃烧焓和标准摩尔生成焓. 发现系列配合物RE(Et₂dtc)₃(phen) (RE＝La, Pr, Nd, Sm～Lu)的多项热化学性质, 如低水合氯化稀土盐在无水乙醇中的溶解焓以及配合物的液相生成反应焓变和固相生成反应焓变、常温比热容、标准摩尔燃烧焓和标准摩尔生成焓都与稀土原子序数作图呈现“三分组现象”. 较集中地反映出配合物中RE³⁺与配体间的化学键有一定程度的共价性, 这是由于稀土离子5s²5p⁶轨道对4f电子的不完全屏蔽引起的.     

三元配合物Dy（Et2dtc）3（phen）的热化学性质

以铜试剂(NaEt2dtc·3H2O)和菲咯啉(phen·H2O)与低水合氯化狄(DyCl3·3.74H2O)在无水乙醇中反应,制得三元固态配合物,化学分析和元素分析确定该化合物的组成为Dy(Et2dtc)3(phen)。IR光谱表明配合物中Dy3 与3个NaEt2dtc中的6个硫原子双齿配位,同时与phen中的2个氮原子双齿配位,可推测其配位数为8。用微热量计测定出298.15 K下液相生成反应的焓变A,H曼(1)为(一19.091±0.015)kJ·mol_。,通过合理的热化学循环计算出固相生成反应焓变△rHmθ(s)为(139.641±0.482)kJ·mol-1;改变反应温度,研究了配合物的液相生成反应的热动力学,配合物的恒容燃烧能△cU用精密转动弹热量计测定为(-16730.21±9.25)kJ·mol-1,其标准燃烧焓△fHmθ和标准生成焓△fHmθ经计算分别为(-16749.42±9.25)kJ·mol-1和(-2019.68±10.19)kJ·mol～1。     

配合物[Sm(C7H5O3)2(C4H6NO2S)]·2H2O的热化学研究

将六水氯化钐,水杨酸与硫代脯氨酸3种物质一起反应,制得了一种新的稀土三元固体配合物[Sm(C7H5O3)2(C4H6NO2S)].2H2O(s)。通过红外光谱、热重差热分析、元素分析等手段确定了其结构与组成。在常压、298.15 K下,分别测定了六水氯化钐、水杨酸、硫代脯氨酸和该配合物在混合溶剂(二甲亚砜∶乙醇∶3 mol.L-1HCl=1∶1∶1)中的溶解焓,并根据热化学原理得出了298.15 K时配合物[Sm(C7H5O3)2(C4H6NO2S)].2H2O(s)的标准摩尔生成焓ΔfHmΘ=(-2913.73±3.10)kJ.mol-1。     

三元配合物Ho(Et2dtc)3(phen)的合成及其热化学性质

改进文献方法,以铜试剂(NaEt2dtc·3H2O)和邻菲咯啉(o-phen·H2O)与低水合氯化钬(HoCl3·3.58H2O)在无水乙醇中反应,制得三元固态配合物.化学分析和元素分析确定该配合物的组成为Ho(Et2dtc)3(phen).IR光谱表明配合物中Ho3 与3个NaEt2dtc中的6个硫原子双齿配位,同时与o-phen中的2个氮原子双齿配位,可推测其配位数为8.用微量热量计测定了298.15 K下液相生成反应的焓变△rHm (1),为(-14.697±0.0376)kJ·mol-1,通过合理的热化学循环计算了固相生成反应焓变△rHm (s),为(117.504±0.619)kJ·mol-1;改变反应温度,研究了配合物的液相生成反应的热力学性质.配合物的恒容燃烧能△cU用精密转动弹热量计测定为(-18687.64±8.22)kJ·mol-1,其标准燃烧焓△cHm 和标准生成焓△fHm 经计算分别为(-18706.85±8.22)和(-70.01±9.37)kJ·mol-1.     

水合氯化镧与二乙氨基荒酸二乙铵配合行为的热化学

在干燥氮气气氛下，以无水乙醇为溶剂，制备了低水合氯化镧与二乙氨基荒酸 二乙铵（D-DDC）的配合物，确定其组成为Et_2NH_2[La(S_2CNEt_2)_4]。用微量热 法测定了298.15 K下水合氯化镧和D-DDC在无水乙醇中的溶解焓和不同温度下二乙 氨基荒酸镧液相生成反应的焓变。在实验和计算基础上，得到了液相生成反应的热 力学参数（活化焓、活化熵和活化自由能）、速率常数和动力学参数（表现活化能 、频率因子和反应基数），通过合理的热化学循环，求得了标题固相反应的焓变。     

La(NCS)_3·4.5H_2O与18C6在乙醇中的配合行为及热化学研究

采用半微量相平衡方法研究了三元体系La(NCS)3·4.5H2O-18C6-C2H5OH在298.15K的溶解度,测定了各饱和溶液的折光率。该体系形成两种化学计量的配合物,其组成分别为:犤La(NCS)318C6犦·4.5H2O?和犤La2(NCS)6(18C6)3犦·9H2O?,?为溶解一致化合物,?为溶解不一致化合物。依据相平衡结果,制备了两种固态配合物,用IR,DTG,TG,DSC及电导对配合物进行了表征。测量了298.15K时18C6,配合物?在无水乙醇中的热效应,依据本文所设计的热化学循环,求得了溶解一致化合物?的标准生成焓,ΔfHm(犤La(NCS)318C6犦·4.5H2O,s)为-3196.7kJ·mol-1。     

Thermal decomposition of Pr[(C5H8NS2)(C12H8N2)]

The thermal behavior of the complex Pr[(C₅H₈NS₂)(C₁₂H₈N₂)] in a dry nitrogen flow was examined by TG-DTG analysis. The TG-DTG investigations indicated that Pr[(C₅H₈NS₂)(C₁₂H₈N₂)] was decomposed into Pr₂S₃ and deposited carbon in one step where Pr₂S₃ predominated in the final products. The results of non-isothermal kinetic calculations showed that the decomposition stage was the random nucleation and subsequent growth mechanism(n = 2/3), the corresponding apparent activation energyE was 115.89 kJ•mol⁻¹ and the pre-exponential constant In[A/s] was 7.8697. The empirical kinetics model equation was proposed as\(f(\alpha ) = \frac{3}{2}(1 - \alpha )[ - 1n(1 - \alpha )]^{\frac{1}{3}} \). The X-ray powder diffraction patterns of the thermal decomposition products at 800 °C under N₂ atmosphere show that the product can be indexed to the cubic Pr₂S₃ phase. The transmission electron microscopy (TEM) of the final product reveals the particle appearance of a diameter within 40 nm. The experimental results show that the praseodymium sulfide nanocrystal can be prepared from thermal decomposition of Pr[(C₅H₈NS₂)(C₁₂H₈N₂)].

     

Total cross sections for electron scattering by polyatomic molecules at 10–1000 eV: C2H2, C2H4, C2H6, C3H6, C3H8 and C4H8

A model complex optical potential (composed of static, exchange, polarization and absorption terms) is employed to calculate the total (elastic and inelastic) electron-atom scattering cross sections from the corresponding atomic wave function at the Hartree-Fock level. The total cross sections (TCS) for electron scattering by their corresponding molecules (C₂H₂, C₂H₄, C₂H₆, C₃H₆, C₃H₈ and C₄H₈) are firstly obtained by the use of the additivity rule over an incident energy range of 10–1000 eV. The qualitative molecular results are compared with experimental data and other calculations wherever available, good agreement is obtained in intermediate-and high-energy region.     

H atom yields from the reactions of CN radicals with C2H2, C2H4, C3H6, trans-2-C4H8, and iso-C4H8

The kinetics and H atom channel yield at both 298 and 195 K have been determined for reactions of CN radicals with C2H2 (1.00+/-0.21, 0.97+/-0.20), C2H4 (0.96+/-0.032, 1.04+/-0.042), C3H6 (pressure dependent), iso-C4H8 (pressure dependent), and trans-2-C4H8 (0.039+/-0.019, 0.029+/-0.047) where the first figure in each bracket is the H atom yield at 298 K and the second is that at 195 K. The kinetics of all reactions were studied by monitoring both CN decay and H atom growth by laser-induced fluorescence at 357.7 and 121.6 nm, respectively. The results are in good agreement with previous studies where available. The rate coefficients for the reaction of CN with trans-2-butene and iso-butene have been measured at 298 and 195 K for the first time, and the rate coefficients are as follows: k298K=(2.93+/-0.23)x10(-10) cm3 molecule(-1) s(-1), k195K=(3.58+/-0.43)x10(-10) cm3 molecule(-1) s(-1) and k298K=(3.17+/-0.10)x10(-10) cm3 molecule(-1) s(-1), k195K=(4.32+/-0.35)x10(-10) cm3 molecule(-1) s(-1), respectively, where the errors represent a combination of statistical uncertainty (2sigma) and an estimate of possible systematic errors. A potential energy surface for the CN+C3H6 reaction has been constructed using G3X//UB3LYP electronic structure calculations identifying a number of reaction channels leading to either H, CH3, or HCN elimination following the formation of initial addition complexes. Results from the potential energy surface calculations have been used to run master equation calculations with the ratio of primary:secondary addition, the average amount of downward energy transferred in a collision DeltaEd, and the difference in barrier heights between H atom elimination and an H atom 1, 2 migration as variable parameters. Excellent agreement is obtained with the experimental 298 K H atom yields with the following parameter values: secondary addition complex formation equal to 80%, DeltaEd=145 cm(-1), and the barrier height for H atom elimination set 5 kJ mol(-1) lower than the barrier for migration. Finally, very low temperature master equation simulations using the best fit parameters have been carried out in an increased precision environment utilizing quad-double and double-double arithmetic to predict H and CH3 yields for the CN+C3H6 reaction at temperatures and pressures relevant to Titan. The H and CH3 yields predicted by the master equation have been parametrized in a simple equation for use in modeling.     

Thermal decomposition of Pr[(C_5H_8NS_2)_3(C_(12)H_8N_2)]

The thermal behavior of the complex Pr[(C5H8NS2)3(C12H8N2)] in a dry nitrogen flow was examined by TG-DTG analysis. The TG-DTG investigations indicated that Pr[(C5H8NS2)3-(C12H8N2)] was decomposed into Pr2S3 and deposited carbon in one step where Pr2S3 predominated in the final products. The results of non-isothermal kinetic calculations showed that the decomposition stage was the random nucleation and subsequent growth mechanism (n = 2/3), the corresponding apparent activation energy ?was 115.89 kJ·mol-1 and the pre-expo-nential constant ln[A/s] was 7.8697. The empirical kinetics model equation was proposed as/(α) =3/2(1-α)[-ln(1-α)]1/3.The X-ray powder diffraction patterns of the thermal decomposition products at 800℃under N2 atmosphere show that the product can be indexed to the cubic Pr2S3 phase. The transmission electron microscopy (TEM) of the final product reveals the particle appearance of a diameter within 40 nm. The experimental results show that the praseodymium sulfide nanocrystal can be prepared from thermal decomposition of Pr[(C5H8NS2)3(C12H8N2)].