硝酸镧与丙氨酸反应的热化学研究

稀土离子具有独特的生理、生化特性．氨基酸是体内蛋白质分子的基本单元,它通过ＤＮＡ,ｍＤ－ＮＡ复制、转录、翻译成不同类型的蛋白质分子．１９２８年Ｆｅｉｆｅｒ首次合成,１９７５年Ａｎｙｈｉｌｅｒｉ报道了稀土氨基酸配合物Ｌａ（Ｇｌｙ）３·Ｃｌ３·Ｈ２Ｏ的抗肿瘤作用．显然,研究稀土氨基酸配合物具有十分重要的意义．近年来,对稀土氨基酸配合物的研究已成为化学和生物学交叉领域的研究热点［１－５］．认识它们的基本热力学性质也变得越来越重要．但是,国内外在这方面的研究尚处于开拓时期． 姜相武等［４］在 ３５℃时对体…     

镧与L-酪氨酸和甘氨酸三元固态配合物的热化学研究

由于稀土元素镧与氨基酸形成的配合物具有抗癌、抗肿瘤活性 ,人们对稀土氨基酸配合物的研究产生了浓厚兴趣。有关这类配合物的制备和表征的研究较多[1～ 4] ,而对其热化学性质的研究较少。我们按文献[5] 方法合成了配合物Ｌａ(Ｔｙｒ)(Ｇｌｙ) 3Ｃｌ3·3Ｈ2 Ｏ(ｓ) ,在自行研制的具有恒定温度环境反应热量计上 ,分别测定了Ｌａ2 Ｏ3(ｓ)、氨基酸 [Ｌ 酪氨酸 (Ｌｙｒ) +甘氨酸 (Ｇｌｙ) ]和配合物在2ｍｏｌ·Ｌ- 1 ＨＣｌ溶液中的溶解焓 ,通过设计的热化学循环得出配合反应焓 ,进而计算出Ｌａ(Ｔｙｒ)(Ｇｌｙ) 3Ｃｌ3·3Ｈ2 Ｏ(ｓ)的标准摩尔…     

硝酸铒与丙氨酸配位反应的热化学研究

稀土氨基酸配合物是一类具有应用前景的化合物,它有杀菌、消炎、抗凝血等作用 [1,2], 1975年 Anghileri报道了 La(Gly)3Cl3· 3H2O具有抗肿瘤作用后,更引起了人们的关注,但多数是研究这类配合物的制备和性质 [3～ 5],而对其进行热化学研究的较少,稀土氨基酸配合物的热力学数据目前尚很缺乏。为此,我们进行了这方面的研究工作。 硝酸铒与丙氨酸固体配合物的合成及相平衡研究已有报道 [3,4],其配位反应的热化学性质研究未见报道。本文用量热法分别测定了配位反应的反应物 [Er(NO3)3· 6H2O＋ 4Ala]和产物 [Er(Ala)4(NO3)3· H2…     

氯化钐与甘氨酸配合物Sm(Gly)2Cl3·3H2O热化学研究

A complex of samarium with glymine， [Sm(Gly)₂Cl₃·3H₂O]， was synthesized and characterized by DSC， TG and DTG. A possible mechanism of thermal decomposition of this complex was suggested. The heat capacities of the complex were measured by a precision adiabatic calorimeter over the temperature range from 82 to 375 K. The solution enthalpies of reactants [SmCl₃·6H₂O+2Gly] and the products [Sm(Gly)₂Cl₃·3H₂O+3H₂O] were determined by an isoperibel solution- reaction calorimeter at 298.15 K， respectively; the standard molar enthalpy of formation of [Sm(Gly)₂Cl₃·3H₂O] was calculated through a designed thermochemical cycle.     

硝酸镝与丙氨酸配位反应的热化学研究

采用新型的具有恒温环境的反应热量计 ,以 2mol L的HCl作溶剂 ,分别测定了 [Dy(NO3) 3·6H2 O +4Ala]和Dy(Ala) 4(NO3) 3·H2 O在 2 5℃时的溶解焓。通过设计的热化学循环得到六水硝酸镝与丙氨酸配位反应的反应焓ΔrHmθ=30 .638kJ mol,并计算出配合物Dy(Ala) 4(NO3) 3·H2 O在 2 98.1 5K时的标准生成焓ΔfHmθ=-3833.8kJ mo     

量热法测定氯化钐与甘氨酸配合物的标准生成焓

稀土在生命科学领域的研究日益受到人们关注,稀土化合物所具有的抑菌、抑癌、消炎等作用及其作用机理的探讨已有报道［１～３］。最近几年稀土在生物领域中的研究又有了新的突破和进展,从稀土与氨基酸、蛋白质、膜脂及膜蛋白的作用到其对ＤＮＡ。ＲＮＡ的影响［１,４］,从稀土的分子水平、细胞及亚细胞水平到动物整体实验的系统研究［５,６］等,分别从不同的层次、不同的水平研究了稀土的生物效应。但至目前为止,稀土的生物效应机理及其对人体的影响尚未得到令人满意的解释。由于氨基酸是构成人体蛋白质的基本单位,故研究稀土与氨基…     

七水氯化铈与甘氨酸丙氨酸三元固态配合物的热化学

合成了Ce3+与甘氨酸丙氨酸混配体配合物, 通过红外光谱分析、元素分析、热重分析和化学分析, 确定了配合物的组成为Ce(Gly)2(Ala)3Cl3*2H2O, 并用溶解量热法分别测定了CeCl3*7H2O(s), 2Gly(s)+3Ala(s)和Ce(Gly)2(Ala)3Cl3*2H2O(s)在2 mol*L-1 HCl中的溶解焓; 再根据盖斯定律设计了一个热化学循环, 计算得到了七水氯化铈与甘氨酸丙氨酸反应的反应焓ΔrHmθ (298.15 K)=29.075 kJ*mol-1, 并求出了Ce(Gly)2(Ala)3Cl3*2H2O(s)标准生成焓△fHmθ [Ce(Gly)2(Ala)3Cl3*2H2O, s, 298.15 K]=-4468.0 kJ*mol-1.     

四水氯化锰与对甲基苯胺配位反应的热化学研究

用溶解量热法测定聚凝相反应的焓变,并进一步得到指定物质未见报道的标准生成焓数据,是一种较准确的研究手段。所得到结果可完善物质的标准热力学性质,满足化学研究与应用的需要。本文选择氯化锰（NnCl2.4H2O)与对甲基苯胺（CH3C6H4NH2,简称p-tol)进行反应,合成了配合物Mn(p-tol)2Cl2。用新型的具有恒定温度环境的反应热量计^[1],以溶解量热法^[2,3],用一定比例的HCl(3.0mol.L^-1)与无水乙醇的合溶液作为量热溶剂,分别测定了反应物,产物的溶解熔,设计了一个新的热化学循环,得到了配位反应的反应焓,并计算出了配合物Mn(p-tol)2Cl2的标准生成焓。     

氯化钆与L-酪氨酸和甘氨酸三元固态配合物的热化学及热分解动力学研究

合成表征了氯化钆与L 酪氨酸和甘氨酸形成的三元固态配合物Gd(Tyr) (Gly) 3 Cl3 ·3H2 O .用具有恒温环境的溶解 -反应热量计 ,测定了配位反应GdCl3 ·6H2 O (s) +Tyr (s) +3Gly (s) =Gd(Tyr) (Gly) 3 Cl3 ·3H2 O (s) +3H2 O (l)在 2 98.15K时的反应焓为 ( 9.45 1± 0 .468)kJ·mol-1 .计算得配合物Gd(Tyr) (Gly) 3 Cl3 ·3H2 O (s)在 2 98.15K时的标准摩尔生成焓为ΔfH m =-( 4 2 69.7± 2 .3 )kJ·mol-1 .并用热分析手段对配合物进行了非等温热分解动力学研究 ,推断配合物第二步热分解反应机理为二级化学反应 ,其动力学方程为 :dα/dT =(A/β)exp( -E/RT) ( 1-α) 2 ,求得分解反应的表观活化能为E =2 15 .17kJ·mol-1 ,指前因子为 10 1 8.71 s-1 .     

A Thermochemical Study of the Reaction of Lanthanum Nitrate with Alanine

IntroductionRare earth ions possess some special functions, in biochemistry and can be used as aprobe to label the calcium ion, moreover, amino acids are the structure unit of proteins, so itis very important to make research on the complexes of rare earth salts with amino acids. Theresearch on the behaviour of the complexes of rare earth salts with amino acids has become aheated point of the research in the crossing field of chemistry and biology in recent years['--'].In order to guide the de…     

谷氨酸和精氨酸与铜离子混配合物的热化学

The Mixed ligands complexes of L glutamic acid and L arginine with Cu(Ⅱ) was synthesized. The composition of the complex was determined by chemical analysis, element analysis and thermal gravity analysis. By solution calorimetry in a reaction calorimeter at 298.2 K,the dissolution enthalpy for the reactant, CuSO4 5H2O(s), L Glutamic acid(s) and L Arginine(s), and the product, Cu稧lu稟rg稴O4 5H2O(s), were determined. They were dissolved in 2 mol稬－1 H2SO4 solution, respectively. A themochemistry cycle was designed, to obtain the coordinate reaction enthalpy change,=(19.745 0.033) kJ穖ol－1, and the standard formation enthalpy of the mixed ligands complex was calculated,=(－3923.145 3.768)kJ穖ol－1. This result offers a basic thermochemistry parameter for the further research of this kind of compounds.     

高氯酸钆与脯氨酸形成配合物的反应热化学研究

稀土氨基酸配合物具有许多特殊的性能,1975年Anghileri等报到了氯化镧与甘氨酸的配合物具有抗肿瘤作用^[1],此后人们又陆续发现这类配合物在医药,防腐剂,动物饲料,农用微肥,钙离子探针,羊毛染色等方面具有广泛的实用价值[2,3],因而引起人们对研究稀土氨基酸配合物的兴趣。但目前这类配合物的制备和性质报道较多^[4,5],基础热化学的研究尚待展开^[6]。     

Synthesis and Determination of Standard Molar Enthalpies of Formation for Complexes of Rare Earth Isothiocyanates with Glycine

Four solid complexes of rare earth isothiocyanates with glycine were synthesized. They were characterized by chemical analysis, elemental analysis, Infrared spectra, X-ray powder diffraction and TO-DSC analysis. Their chemical formulae were proved to be RE(NCS)2.Gly .H2O, where RE is La, Ce, Pr or Nd. The integral heats of solution of RE(NCS)3.3Gly. H2O in water, of RE(NCS)2. 7H2O in aqueous glycine solution and of glycine in water have been measured calorimetricaliy at 298. 15K. By means of a thermochemical cycle suggested in this paper, the standard molar enthalpies of formation for RE(NCS)2. 3Gly.H2O(c) were obtained and their lattice energies were calculated.     

Thermochemical studies of 1-hydroxyisoquinoline, 5-hydroxyisoquinoline and 1,5-dihydroxyisoquinoline

The standard (p^° = 0.1 MPa) molar enthalpies of formation, , for crystalline 1-hydroxyisoquinoline, 5-hydroxyisoquinoline and 1,5-diidroxyisoquinoline, were derived from the standard molar enthalpies of combustion, in oxygen, at the temperature 298.15 K, measured by static bomb-combustion calorimetry. The standard molar enthalpies of sublimation, , at T = 298.15 K, were determined by Calvet microcalorimetry. The results were as follows:

1-Hydroxyisoquinoline	4395.1 ± 1.5	113.6 ± 2.2
5-Hydroxyisoquinoline	4455.2 ± 1.9	109.6 ± 2.1
1,5-Dihydroxyisoquinoline	4194.1 ± 2.2	123.6 ± 2.2

Full-size table

     

Thermochemical Study of 1-Methylhydantoin

Using static bomb combustion calorimetry, the combustion energy of 1-methylhydantoin was obtained, from which the standard molar enthalpy of formation of the crystalline phase at T = 298.15 K of the compound studied was calculated. Through thermogravimetry, mass loss rates were measured as a function of temperature, from which the enthalpy of vaporization was calculated. Additionally, some properties of fusion were determined by differential scanning calorimetry, such as enthalpy and temperature. Adding the enthalpy of fusion to the enthalpy of vaporization, the enthalpy of sublimation of the compound was obtained at T = 298.15 K. By combining the enthalpy of formation of the compound in crystalline phase with its enthalpy of sublimation, the respective standard molar enthalpy of formation in the gas phase was calculated. On the other hand, the results obtained in the present work were compared with those of other derivatives of hydantoin, with which the effect of the change of some substituents in the base heterocyclic ring was evaluated.