L-苏糖酸锰的制备及标准生成焓

The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃ for certain time. The composition of the new compound was determined by chemical and elemental analyses and its formula fits Mn(C₄H₇O₅)₂·H₂O, the IR spectra indicated that Mn²⁺ in the compound coordinates to oxygen atom of the carboxyl group, while the proton of the carboxyl group is dissociated, it was assumed that the coordination number of Mn²⁺ was 4. The results of TG-DTG showed that the compound have fairish stability, the intermediate and final product of the thermal de-composition of the compound are Mn(C₄H₇O₅)₂ and MnO₂, respectively. The constant volume combustion energy of the compound, Δ_cE, were determined by a precise rotating-bomb calorimeter at 298.15K, it was (-3384.30±1.21)kJ·mol^-1, its standard enthalpy of Combustion,Δ_cH_m^?,and standard enthalpy of formation,Δ_fH_m^? , were calculated. They are (-3383.07±1.21)kJ·mol^-1 and (-2 571.68±1.63)kJ·mol^-1, respectively.     

锌(Ⅱ)-氨基酸水杨醛席夫碱-α-氨基酸三元配合物的稳定性

The stability constants of binary complexes of Zn(Ⅱ)-α-amino acid and ternary complexes of Zn(Ⅱ)-N-Salicylideneaminio acid (ligand A)-α-amino acid(ligand B) at (25±0.1)℃ and in the presence of 0.1 mol·L^-1 KNO₃ have been determined by pH method. The α-amino acid(Aa) used were Glycine(Gly), L-Serine(Ser), L-Leucine(Leu), L-Proline(Pro) and L-Phenylalanine(Phe). It was found that the linear free energy relationship (LFER) exists nicely between the following parameter pairs logβ₁₀₂ and pK^B₂, logβ₁₁₁ and pK^B₂, and logβ₁₁₁ and pK^A₂. The ΔlgK was used to characterize the stability of ternary complexes related to the stability of parent binary complexes. The hydrophobic interaction between ligands in the ternary complexes was studied.     

金属离子与卟啉的嵌入反应动力学研究——邻苯二甲酸缓冲溶液中溴化间-四(N-乙酸甲酯基-3-吡啶基)卟啉与Cu(Ⅱ)的配位反应

Kinetics of the coordination reaction of tetrakis(N-carbomethoxymethyl-3-pyridyl) porphyrin(abbr. H₂T_β-N-ACMSPyP) with Cu(Ⅱ) ion has been studied in o-phthalic acid buffer system in an ionic strength of 0.5mol·dm^-3(KCI) at 35.0±0.1℃.The reaction is catalyzed by o-phthalic ion. The effect of concentration of the cata-lyst, metal ion and pH value of solution was discussed. The kinetics equation of the reaction were obtained as d[CuP⁴⁺]/dt=16.15{(1.0+3.35×10⁵[PT^2-]²)/1.0+1.57×10^-4[H⁺]²}[Cu²⁺][P]_T. The mechanism of the reaction was proposed. The deformation of the ring of porphyrins is the general condition in the reaction.     

Lu(Et2dtc)3(phen)的生成反应焓变、摩尔热容和恒容燃烧能测定

A ternary solid complex Lu(Et₂dtc)₃(phen) has been obtained from the reaction of hydrated lutetium chloride with sodium diethyldithiocarbamate (NaEt₂dtc), and 1,10-phenanthroline (o-phen·H₂O) in absolute ethanol. IR spectrum of the complex indicates that Lu³⁺ binds with sulfur atom in the Na(Et₂dtc)₃ and nitrogen atom in the o-phen. The enthalpy change of liquid-phase reaction of formation of the complex, Δ_rH_m^Ө (l), was determined to be (-32.821 ± 0.147 ) kJ·mol^-1 at 298.15 K by an RD-496 Ⅲ type heat conduction microcalormeter. The enthalpy change of the solid-phase reaction of formation of the complex, Δ_rH_m^Ө (s), was calculated to be (104.160 ± 0.168) kJ · mol^-1 on the basis of an appropriate thermochemistry cycle. The thermodynamics of liquid-phase reaction of formation of the complex was investigated by changing the temperature of liquid-phase reaction. Fundamental parameters, such as the activation enthalpy (ΔH_≠^Ө), the activation entropy (ΔS_≠^Ө), the activation free energy (ΔG_≠^Ө), the apparent reaction rate constant (k), the apparent activation energy (E), the pre-exponential constant (A) and the reaction order (n), were obtained by combination the reaction thermodynamic and kinetic equations with the data of thermokinetic experiments. The molar heat capacity of the complex, c_m, was determined to be (82.23 ± 1.47) J·mol^-1·K^-1 by the same microcalormeter. The constant-volume combustion energy of the complex, Δ_cU, was determined as (-17 898.228 ± 8.59) kJ·mol^-1 by an RBC-Ⅱtype rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, Δ_cH_m^Ө, and standard enthalpy of formation, Δ_fH_m^Ө, were calculated to be (-17 917.43 ± 8.11) kJ·mol^-1 and (-859.95 ±10.12) kJ·mol^-1, respectively.     

烷基钴肟及其β-环糊精包结物水溶液中氨取代反应平衡常数测定

The axial coordinate water substitution reactions of alkylaquacobaloximes (alkyl=n-C₃H₇, n-C₄H₉, i-C₄H₉, n-C₅H₁₁, Br(CH₂)₃, PhCH₂) by ammonia in aqueous solution were studied in the absence and presence of β-cyclodextrin (β-CD). The equilibrium constants were measured by UV-vis spectroscopy. It has been found that (i) comparing with that in the absence of β-CD, the equilibrium constant were influenced slightly in the presence of β-CD, (ii) with increasing electron-withdrawing ability of the alkyl groups, the equilibrium constants were increased.     

MULTIDENTATE LIGAND EXCHANGE KINETICS:REACTIONS OF AMINOCARBOXYLATO-FERRATE(Ⅲ) COMPLEXES WITH 4-(2-PYRIDYLAZO) RESORCINOL

The kinetics and mechanism of ligand substitution reactions of nitnlotriacetatoiron(Ⅲ),(Fe(NTA)],and N-(2-hydroxycthyl)-ethylencdiaminetriacetatoiron(Ⅲ),[Fe(HEDTA)],complexes with 4-(2-pyridylazo) resorcinol (Par) has been investigated at pH=9.0±0.02,I=0.1mol·l^-1 (NaClO₄,and temp.=25±0.1℃ and 30±0.1℃ respectively. The reaction has been studied spectrophotometrically at 496 nm. (λmax of Fe(Par)₂. In both reactions the final product was [Fe(Par)₂]^-. The values of second order rate constants for NTA and HEDTA exchange reactions are (10.0±0.8)×10¹¹·mol^-1·s^-1 and (2.7±0.1)×10^-1·mol^-1·s_-1 respectively. The reactions of NTA and HEDTA exchange were studied in the pH range 6-9.5 and 7-10.85 respectively. The rate of reacton of [Fe(NTA)] with HPar^- first increases with pH and then levels off. However,in the case of [Fe(HEDTA)] reaction,the rate increases monotonically with increase of pH in the specified range.     

[Cu(TO)2(H2O)4](PA)2的合成和晶体结构

[Cu(TO)₂(H₂O)₄](PA)₂ was prepared by mixing the aqueous solution of 1,2,4-triazol-5-one(TO) and Cu(PA)₂. The molecular structure and crystal structure of the title complex was determined by X-ray single crystal diffraction method. The crystal is triclinic, space group with a=0.7321(1)nm,b=0.7474(2)nm,c=1.3649(3)nm;α=88.65(2)°,β=85.63(1)°,γ=63.35(1)°;V=0.6655(2)nm³,Z=1. The Cu²⁺ coordinated with two TO molecule through its 2-nitrogen atom and four water molecules and showed an octahedral configuration.     

1,10-邻菲咯啉-铜(Ⅱ)-L-蛋氨酸配合物的合成、表征及其分子结构

The complex [Cu(L-met)(phen)(H₂O)]NO₃·H₂O has been synthesized and investigated by elemental analysis, molar conductivity, spectroscopic and X-ray diffraction methods, where phen=1,10-phenanthroline and L-met=L-methioninate group. The complex crystallized in the monoclinic space group P2₁ with a=12.053(2)?, b=6.886(1)?, c=13.385(3)?, β=113.59(3)°, V=1018.1(3)?³, Z=2,D_c=1.598g·cm^-3, μ=1.223mm^-1, F(000)=506, R₁=0.0306, and wR₂=0.0742. The copper(Ⅱ) atom is ligated in a distorted square-pyramidal geometry by two nitrogen atoms of one phen and the amino nitrogen atom , one carboxylate oxygen atom of L-met in the base plane, and an aqua at the apical position. A one-dimensional chain configuration formed by the hydrogen-bonding and weak Cu-O (the uncoordinated carboxyl oxygen atom) coordination interactions be-tween neighboring [Cu(L-met)(phen)(H₂O)]⁺ cations. CCDC: 183368.     

钾的N-酰化牛磺酸配合物的合成、表征及其晶体结构

The title complex(K(C₉H₁₃NO₅S₂)(H2O)) was synthesized by the reaction of p-tolysulfonyl chloride, taurine and potassium hydrate in water-methanol-ethanol solution. The crystal structure was determined by X-ray diffraction method and the chemical formula weight of the complex is 336.44. The crystal structure of the title complex belongs to orthorhombic space group Pbca and cell parameters: a=0.853 31(12) nm, b=0.820 42(12) nm, c=3.989 4(6) nm. V=2.792 8(7) nm³, Z=8, D_c=1.600 g·cm^-3, μ=0.699 mm^-1, F(000)=1 400. The compound is an one-dimension chain complex of infinite length which are connected with hydrogen bond and bridging coordination water. The difference and same of the complexes were discussed. CCDC: 244938.     

N，N，N′，N′-四丁基丙二酰胺从硝酸盐介质中萃取铈(Ⅲ)

Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work， the extraction of Ce(Ⅲ) with N，N，N′，N′-tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid， TBMA and salt-ing-out agent (LiNO₃) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO₃)₃·3TBMA and Ce(NO₃)₃·4TBMA， respectively. The ap-parent extraction constants and the enthalpy of the extraction were calculated based on the extraction data， which are logK_ex1=3.97， logK_ex2=4.75 and Δ_rH_m^?=-31.25kJ·mol^-1， respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism.     

四氮杂大环与镧系金属配合物的热力学研究

The stability constants of the 1:1 complexes of H4L2 (5,12-dipheny1-7, 14-dimethyl-1,4,8,11-tetraazamasrocyclotetradecane-N', N", N"',N""-tetraacetic acid) with Ln3+ (Ln=La, Nd, Pr, Sm, Eu, Gd, Dy, Yb) were determined by potemtiometric titrations in 0.5mol•L-1 KCl at 40±0.1℃, 50±0.1℃ and 60±0.1℃ respectively. The △H, △S and △G of the coordination reactions of H4L2 with Ln3+ were given. Influences of the steric effect and temperature changes on the stability lanthanide complexes were discussed thermodynamically.     

溶液中N-乙酸基取代氮氧杂大环及其配合物稳定性研究

用pH电位滴定法在25℃,0.5mol·L~(-1)KNO_3水溶液中测定了三种大环化合物:H_2L~1(1,12-二氮杂-3,4:9,10-二苯并-5,8-二氧杂环十五烷-N,N＇-二乙酸);H_3L~2(1,12,15-三氮杂-3,4:9,10-二苯并-5,8-二氧杂环十七烷-N,N＇,N″-三乙酸)和H_2L~3(1,15-二氮杂-3,4:12,13-二苯并-5,8,11-三氧杂环十八烷-N,N′-二乙酸)的逐级质子化常数.又测定了它们与Cu~(2+)、Ni~(2+)、Pb~(2+)配合物的稳定常数,以及H_2L~3与镧系金属La~(3+)、Pr~(3+)、Nd~(3+)、Eu~(3+)、Sm~(3+)、Gd~(3+)、Dy~(3+)、Yb~(3+)配合物的稳定常数.讨论了三种大环化合物质子化的一般顺序及其与各种离子配位时稳定性选择规律.说明了影响配位稳定性的有关因素.     

Thermodynamic investigations of methyl tert-butyl ether and water mixtures

Interactions between methyl tert-butyl ether (MTBE) and water have been investigated by scanning calorimetry, isothermal titration calorimetry, densitometry, IR-spectroscopy, and gas chromatography. The solubilization of MTBE in water at 25 °C at infinite dilution has ΔH° = -17.0 ± 0.6 kJ mol(-1); ΔS° = -80 ± 2 J mol(-1) K(-1); ΔC(p) = +332 ± 15 J mol(-1) K(-1); ΔV° = -18 ± 2 cm(3) mol(-1). The signs of these thermodynamic functions are consistent with hydrophobic interactions. The occurrence of hydrophobic interaction is further substantiated as IR absorption spectra of MTBE-water mixtures show that MTBE strengthens the hydrogen bond network of water. Solubilization of MTBE in water is exothermic whereas solubilization of water in MTBE is endothermic with ΔH° = +5.3 ± 0.6 kJ mol(-1). The negative mixing volume is explained by a large negative contribution due to size differences between water and MTBE and by a positive contribution due to changes in the water structure around MTBE. Henry's law constants, K(H), were determined from vapor pressure measurements of mixtures equilibrated at different temperatures. A van't Hoff analysis of K(H) gave ΔH(H)° = 50 ± 1 kJ mol(-1) and ΔS(H)° = 166 ± 5 J mol(-1) K(-1) for the solution to gas transfer. MTBE is excluded from the ice phase water upon freezing MTBE-water mixtures.     

Potentiometric study of binary complexes of methyl 2-pyridyl ketone oxime, phenyl 2-pyridyl ketone oxime and diacetyl monooxime with some transition and heavy metal ions in aqueous solution

The complexation reaction between some oximes including methyl-2-pyridylketone oxime (MPKO), phenyl-2-pyridylketone oxime (PPKO) and diacetyl monooxime (DMO) with some transition and heavy metal ions Co2+, Ni2+, Zn2+, Pb2+, Fe2+, Fe3+, Cr3+ and La3+ has been studied potentiometrically in aqueous solution at 25+/-0.1 degrees C and ionic strength (mu) of 0.1M supported by KCl. The overall stability constants logbeta's of respective species were obtained by computer refinement of pH-volume data using BEST program. The best model among the several proposed models was selected according to the lowest sigma(fit) value. The main species in binary systems are ML, ML2, MLH, MLH2, ML2H, ML2H2, MOHL, M(OH)2L, M(OH)L2 and M(OH)2L2 (L = MPKO or PPKO or DMO).     

A new fluorescent probe for zinc(II): an 8-hydroxy-5-N,N-dimethylaminosulfonylquinoline-pendant 1,4,7,10-tetraazacyclododecane

A new fluorescent probe for Zn2+, namely, 8-hydroxy-5-N,N-dimethylaminosulfonylquinolin-2-ylmethyl-pendant cyclen (L8), was designed and synthesized (cyclen=1,4,7,10-tetraazacyclododecane). By potentiometric pH, 1H NMR, and UV spectroscopic titrations, the deprotonation constants pKa1-pKa6 of L(8)4 HCl were determined to be <2, <2, <2 (for amino groups of the cyclen and quinoline moieties), 7.19+/-0.05 (for 8-OH of the quinoline moiety), 10.10+/-0.05, and 11.49+/-0.05, respectively, at 25 degrees C with I=0.1 (NaNO3). The results of 1H NMR, potentiometric pH, and UV titrations, as well as single-crystal X-ray diffraction analysis, showed that L8 and Zn2+ form a 1:1 complex [Zn(H-1L8)], in which the 8-OH group of the quinoline ring of L8 is deprotonated and coordinates to Zn2+, in aqueous solution at neutral pH. On addition of one equivalent of Zn2+ and Cd2+, the fluorescence emission of L8 (5 microM) at 512 nm in aqueous solution at pH 7.4 [10 mM HEPES with I=0.1 (NaNO3)] and 25 degrees C increased by factors of 17 and 43, respectively. We found that the cyclen moiety has the unique property of quenching the fluorescence emission of the quinolinol moiety when not complexed with metal cations, but enhancing emission when complexed with Zn2+ or Cd2+. In addition, the Zn2+-L8 complex [Zn(H-1L8)] is much more thermodynamically and kinetically stable (Kd{Zn(H-1L8)}=[Zn2+]free[L8]free/[Zn(H-1L8)]=8 fM at pH 7.4) than the Zn2+ complexes of our previous Zn2+ fluorophores ([Zn(H-1L2)] and [Zn(L3)]). Furthermore, formation of [Zn(H-1L8)] is much faster than those of [Zn(H-1L2)] and [Zn(L3)]. The staining of early-stage apoptotic cells with L8 is also described.     

N-苄基甘氨酸-N-乙基磷酸离解常数及其有关配合物稳定常数的确定

用 p H滴定法测定了标题化合物在 2 5± 0 .1℃、3 5± 0 .1℃和 4 5± 0 .1℃ KNO3 存在下的离解常数 ;计算了 2 5± 0 .1℃离解反应的焓变Δr Hm和熵变Δr Sm。确定了 2 5± 0 .1℃ KNO3 存在下 ,它与 Co( )、Ni( )及Cu( )形成的配合物的稳定常数     

链酚胺型配体锌(Ⅱ)配合物模拟碳酸酐酶研究

合成了酚胺型链状配体,N,N'-二(2-羟基苄基)丙二胺(H~2L)及其Zn(Ⅱ)配合物(ZnL),通过元素分析、IR和^1HNRM等手段进行了表征。采用pH电位滴定法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,测定了配体的质子化常数以及配体与金属离子Zn(Ⅱ)配位反应平衡常数。讨论了配体与金属离子Zn(Ⅱ)的配位情况,得到了配位酚羟基的解离常数。运用分光光度法,在25℃±0.1℃,I=0.1mol·dm^-^3(KNO~3)条件下,在pH=5.5～9.0(50mmol·dm^-^3缓冲溶液)范围内,研究了配合物作为碳酸酐酶模拟物催化对-硝基苯酚乙酸酯(NA)水解动力学,得到了NA酯水解的配合物催化速率常数k~N~P。实验结果表明,ZnHL^+的配位酚羟基的解离常数pK~a为6.83;催化速率常数k~N~P与pH之间不存在Sigmoidal型曲线关系,而是在pH值中性附近有最大值,ZnHL^+对NA酯水解有很好的催化效果,并且采取双重催化机理,是碳酸酐酶很好的模拟物。     

Bis- and tris-(3-aminopropyl) derivatives of 14-membered tetraazamacrocycles containing pyridine: synthesis, protonation and complexation studies

New N-(3-aminopropyl) (L1, L2) and (2-cyanoethyl) (L3, L4) derivatives of a 14-membered tetraazamacrocycle containing pyridine have been synthesized. The protonation constants of L1 and L2 and the stability constants of their complexes with Ni2+, Cu2+, Zn2+ and Cd2+ metal ions were determined in aqueous solutions by potentiometry, at 298.2 K and ionic strength 0.10 mol dm(-3) in KNO3. Both compounds have high overall basicity due to the presence of the aminopropyl arms. Their copper(II) complexes exhibit very high stability constants, which sharply decrease for the complexes of the other studied metal ions, as usually happens with polyamine ligands. Mono- and dinuclear complexes are formed with L2 as well as with L1, but the latter exhibits mononuclear complexes with slightly higher K(ML) values while the dinuclear complexes of L2 are thermodynamically more stable. The presence of these species in solution was supported by UV-VIS-NIR and EPR spectroscopic data. The single crystal structures of [Cu(H2L2)(ClO4)]3+ and [CoL3Cl]+ revealed that the metal centres are surrounded by the four nitrogen atoms of the macrocycle and one monodentate ligand, adopting distorted square pyramidal geometries. In the [CoL3Cl]+ complex, the macrocycle adopts a folded arrangement with the nitrogen atom opposite to the pyridine at the axial position while in the [Cu(H2L2)(ClO4)]3+ complex, the macrocycle adopts a planar conformation with the three aminopropyl arms located at the same side of the macrocyclic plane.     

Novel chiral N4S2- and N6S3-donor macrocyclic ligands: synthesis,protonation constants,metal-ion binding and asymmetric catalysis in the Henry reaction

New hydrophobic chiral macrocyclic ligands L1-L3 with chiral diamino and thiophene moieties have been synthesized by the Schiff base condensation approach. Protonation constants of L1 and L2 were determined by potentiometry titration. Metal-ion binding experiments exhibited that L1 and L3 are pronounced in selective recognition, Ag+, Cu2+ and Ca2+ ions among the surveyed metal ions (Cu2+, Co2+, Ni2+, Zn2+, Cd2+, Pb2+, Ag+, Li+, Na+, K+, and Ca2+). L1 was found to spectroscopically detect the presence of Cu2+ and Ca2+ to function as a multiple readout sensor. The detection limit for Ca2+ ions was found to be 9.8 x 10(-5) M in CH2Cl2-MeOH solution. The trimeric chiral ligand L3 has been shown to be an efficient auxiliary in a Zn(II)-mediated enantioselective Henry reaction.     

胶束溶液中某些氨基酸和二肽的解离常数

用ｐＨ电位法测定了在ＳＤＳ（十二烷基磺酸钠）胶束溶液中甘氨酰丙氨酸和六种氨基酸（甘氨酸、丙氨酸、缬氨酸、亮氨酸、异亮氨酸、苯丙氨酸）的两级酸解离常数ｐＫａ１和ｐＫａ２,发现与水溶液相比,ｐＫａ值均显著增加,即ＳＤＳ胶束形成强烈抑制质子解离,结合＾１ＨＮＭＲ测定结果,讨论了ｐＫａ１和ｐＫａ２随ＳＤＳ浓度的变化规律以及与各配体自身结构的关系。