固相配位化学反应研究 XXIII: 一取代基五氰合铁(II)类配合物热分解反应的研究

本文以气相色谱法为主要手段, 配合Mossbauer谱、红外光谱等结构分析方法, 研究了一系列一取代基五氰合铁(II)类配合物Na2[Fe(CN)5L]·mH2O及Na3[Fe(CN)5L']·nH2O(L=NO^+、N2H5^+、enH^+, L'=NH3、H2O、Py)的热分解反应。结果表明所有一取代五氰合铁(II)配合物热分解过程中都形成相同的中间化合物Na4[Fe(CN)6]和Fe2[Fe(CN)6], 各配合物热分解放出取代基L(L')的温度次序与L(L')在光谱化学序列中的次序一致。本文以亚硝基铁氰化钠为代表, 详细讨论了该系列配合物的热分解反应机理以及热稳定性的规律性。     

Kinetics of solid state thermal decomposition reactions

The author wishes to thank Prof. C. G. R. Nair, Dr. V. R. Gowarikar, Mr. M. R. Kurup and Dr. K. V. C. Rao for their encouragements. Thanks are due to Prof. P. M. Madhusudanan and Dr. K. Krishnan for helpful discussions and to Director, VSSC for the kind permission to publish this work.     

Studies on Cr(III) complexes with glycilglycine in the solid state

Two isomers of the trinuclear Cr(III) complex with glycilglycine have been separated in the solid state. Their properties have been examined by spectroscopic, EPR, and magnetic methods, and the structures of these compounds are suggested.     

The thermal decomposition of some Cr(III) complexes

The thermal decomposition reactions of the following chromium(III) complexes were investigated: Cr(CH₃COO)₃·2 H₂O, [C_r3O(CH₃COO)₆(H₂O)₃]Cl·2 H₂O and [Cr₃O(CH₂ClCOO)₆(H₂O)₃]Cl·6H₂O. Simultaneous TG/DTG/DTA were applied nonisothermal conditions. From the recorded curves, the activation energiesE _a were calculated for all the thermal decomposition steps. Appropriate chemical reactions were attributed to the thermal effects, with consideration to the X-ray diffraction and IR spectra results.

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Zusammenfassung Für die Untersuchung der thermischen Zersetzungsreaktion der Chrom(III)-Komplexe Cr(CH₃COO)₃·2H₂O [C_r3O(CH₃COO)₆·(H₂O)₃]Cl2H₂O und [C_r3O(CH₂ClCOO)₆·(H₂O)₃]C₁₆H₂O wurde simultane TG/DTG/DTA unter nichtisothermen Bedingungen eingesetzt. Ausgehend von den aufgezeichneten Kurven wurden für alle Schritte der Zersetzungsreaktion die E_a-Werte berechnet. In Übereinstimmung mit röntgenographischen und IR-spektroskopischen Ergebnissen wurden den thermischen Effekten passende chemische Reaktionen zugeordnet.

     

Primary decomposition mechanism of cobalt(III) nitrotetrazolatoammine complexes

Russian Journal of General Chemistry - Results of quantum-chemical simulation of isolated molecules of (5-nitrotetrazolato-N 2)pentaaminecobalt(III) perchlorate, cis-bis(5-nitrotetrazolato-N...     

固相配位化学反应研究 52: 室温固-固相化学反应合成氨基酸铜配合物

本文报道室温固-固相化学反应一步法合成氨基酸铜配合物。trans-Cu(Gly)2.H2O、cis-Cu(GlY)2.H2O、trans-Cu(DL-Ala)2、trans-Cu(DL-Ala)2.H2O、trans-Cu(DL-Val)和trans-Cu(DL-Leu)2, 经元素分析、IR、XRD、DTA测定了配合物的组成及几何构型。并初步讨论了室温固相反应合成机理。     

Thermal decomposition reactions of amminecobalt(III)complexes

Simultaneous TG-DTG-DTA studies under non-isothermal conditions on [Co(NH₃)₆]Cl₃, [Co(NH₃)₅]Cl₂ and [Co(NH₃)]₂(C₂O₄)₃.4H₂O complexes have been carried out in air and argon atmospheres in the temperature range 293–1273 K. All the dissociation processes occur in three main stages. The kinetics of thermal decomposition of the complexes have been evaluated from the dynamic weight loss data, to determine the most probably mechanisms of the stages on the basis of statistical analysis. The decomposition of the compounds was controlled by diffusion and phase boundary reactions except stage III of the oxalate complex in argon (random nucleation). The activation energiesE _a of the particular stages of the thermal decomposition were calculated.

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Zusammenfassung Simultane TG-DTG-DTA-Untersuchungen an den Komplexverbindungen [Co(NH₃)₆]Cl₃, [Co(NH₃)₅Cl]Cl₂ und [Co(NH₃)₆]₂(C₂O₄)₃.4H₂O unter nichtisothermen Bedingungen wurden in Luft und Argonatmosphäre bei 293–1273 K durchgeführt. Die Zersetzung läuft in jeweils drei Stufen ab. Für die kinetische Auswertung der thermischen Zersetzung der Komplexverbindungen aus den dynamischen Gewichtsabnahmekurven wurde der wahrscheinlichste Mechanismus der einzelnen Stufen mit Hilfe von statistischen Analysen ermittelt. Die Zersetzung der Komplexverbindungen wird meist durch Diffusions- und Phasengrenzreaktionen kontrolliert, nur bei der 3. Stufe des Oxalatkomplexes in Argon herrscht statistische Keimbildung. Die AktivierungsenergienE _a der einzelnen Zersetzungsstufen werden berechnet.

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293–1273 — [Co(NH₃)₆]Cl₃, [Co(NH₃)₅Cl]G₂ [Co(NH₃)₆]₂(C₂O₄)₃.4H₂O. . , . , III , . _a .

     

Studies on the bacterial activity of cobalt(III) complexes. Part II. Cobalt(III) aminoacidato-complexes

Summary Cobalt(III) complexes of the typetrans-[Co(AA)₂(ox)] (where AA = aminoacidato, gly = glycinato, sar = sarcosinato, DL-ala = DL-alaninato, L-ala = L-alaninato; ox = oxalate); [Co(L-val)₂CO₃] and DL-[Co(en)₂sar]I₂ where L-val = L-valinato, en = ethylenediamine) have been investigated for their bacterial activity againstEscherichia coli B using well-cultured techniques on EMB agar and in minimal glucose media. The activities decrease in the order:trans-(N)(+)K[Co(sar)₂(ox)] >trans-(N)(+)K[Co(L-ala)₂(ox)] >trans-(N)(–)K[Co (gly)₂(ox)] >trans-(N)(+)K[Co(DL-ala)₂(ox)] >trans-(N)(+)K[Co(gly)₂(ox)] >trans(+)K[Co(DL-ala)₂(ox)] >trans-K[Co(L-val)₂CO₃].     

Kinetic study of the thermal decomposition of cobalt(III) oxyhydroxide

The kinetics of thermal decomposition of CoOOH have been studied by analysis of isothermal weight loss data under vacuum. The comparison of linear correlation coefficients of different kinetic expressions applied to these data does not allow an understanding of the mechanism, even when significance tests are performed (t test). A single value of the activation energy (193 kJ mol^?1) is obtained from the Arrhenius plots, and is relatively independent of the choice of rate law. On the other hand, a change in the mechanism of formation of Co₃O₄ with temperature cannot be inferred from analysis of isothermal data. Thus, the statement of some authors that from formal kinetics it is possible to distinguish the proton and electron transfers involved in the transformation appears unacceptable.     

Study of the thermal behavior of Al(III) and In(III)-diclofenac complexes in solid state

The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of 2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results in two kinetic behavior patterns.     

Unusual coordination mode of tetradentate Schiff base cobalt(III) complexes

Contrary to the stereotype, Jacobsen's catalyst, chiral (salcy)Co(III)OAc adopts an unusual binding mode. The tetradentate {ONNO} ligand does not form a square plane but wraps cobalt in a cis-β fashion while acetate is chelating.     

Studies on the thermal decomposition of alkali metal thiosulphatobismuthates(III)

The thermal decomposition of thiosulphatobismuthates(III) of alkali metals was investigated. The general formulae of the thiosulphatobismuthates are M₃[Bi(S₂O₃)₃]·H₂O where M = Na, K, Rb or Cs, and M₂Na[Bi(S₂O₃)₃]·H₂O where M = K or Cs.Typical thermal curves for thiosulphatobismuthates(III) and the results obtained in thermal, X-ray, chemical and spectrophotometrical analyses of the decomposition products are shown. The results were used to determine three stages of the thermal decomposition. At the first stage, at about 200°C, hydrated compounds are dehydrated. At the second stage, above 200°C, there is a rapid decrease in mass which is caused by evolving sulphur dioxide; bismuth sulphide and an intermediate decomposition product are formed. At about 320°C the thermal decomposition products are bismuth sulphide and alkali metal sulphate.     

Studies on solid state synthesis and the oxygenation property of cobalt (II) Schiff base (vanilline polyamine) complexes

Three new cobalt complexes were synthesized by solid-state reaction at room temperature and the resultant Co complexes reacted with two equivalent oxygen molecules at room temperature to produce the oxygenated complexes [Co·(L₁)₂·(O₂)₂](NO₃)₂·2H₂O (L₁ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl)-diethylenetriamine), [Co·(L₂)₂·(O₂)₂](NO₃)₂·2H₂O (L₂ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl)-triethylenetetramine), and [Co·(L₃)₂·(O₂)₂](NO₃)₂·2H₂O (L₃ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl-tetraethylenepentamine). The oxygenated complexes were characterized by elemental analysis, IR (Infrared), ¹H-NMR (Nuclear Magnetic Resonance), and UV-Vis (Ultraviolet Visual) spectrometry, and TG/DTA (Thermogravimetry/Differential Thermal Analysis) analysis, and molar conductance. The coordinated oxygen contents in the oxygenated complexes were also determined by weight method. It was supposed that only one O₂ molecule coordinated to the Co ion forming a superoxo type oxygenated complex. Translated from Acta Chimica Sinica, 2006, 64(15): 1517–1522 (in Chinese)     

Thermal studies on oxalate complexes. III. Complexes of cobalt(III) and cobalt(II)

The decomposition of K₂[Co(C₂O₄)₂] and K₃[Co(C₂O₄)₃] has been studied using TG. In the case of the latter compound, the first step involves the rupture of all the oxalates and one of the resultant carbonates to liberate CO₂ and three molecules of CO. Subsequent steps involve the loss of CO₂. In the case of K₂[Co(C₂O₄)₂], four decomposition reactions are observed. The first involves the loss of only CO. Subsequent steps involve loss of CO₂, CO₂ and CO, and CO₂, respectively. Basic carbonates appear to be the intermediate products. Kinetic parameters are presented for most of the reactions.     

Thermal intramolecular electron transfer reactions of [N,N′-ethylene-bis(salicylideneaminato)](2,4-pentanedionato)cobalt(III) complexes in the solid state

The title complexes with the formula Co(salen)L where L is a series of 2,4-pentanedionates underwent thermally induced one-electron transfer reactions from L to Co(III). The reaction left behind a stoichiometric amount of the crystalline Co^II(salen) complex which took up oxygen in a molar ratio of Co:O₂ = 2:1. The kinetic analyses showed that the electron transfer reaction rate was apparently dominated by activation entropy rather than by activation enthalpy.     

Kinetics of thermal decomposition of iron(III) dicarboxylate complexes

Summary Tris(dicarboxylate) complexes of iron(III) with oxalate, maleate, malonate and phthalate viz. K₃[Fe(C₂O₄)₃]×3H₂O (1), K₃[Fe(OOCCH₂COO)₃]×3H₂O (2), K₃[Fe(OOCCH=CHCOO)₃]×3H₂O (3), K₃[Fe(OOC-1,2-(C₆H₄)-COO)₃]×3H₂O (4) have been synthesized and characterized using a combination of physicochemical techniques. The thermal decomposition behaviour of these complexes have been investigated under dynamic air atmosphere upto 800 K. All these complexes undergo a three-step dehydration/decomposition process for which the kinetic parameters have been calculated using Freeman-Carrol model as well as using different mechanistic models of the solid-state reactions. The trisoxalato and trismalonato ferrate(III) complexes undergo rapid dehydration at lower temperature below 470 K. At moderately higher temperatures (i.e. >600 and 500 K, respectively) they formed bis chelate iron(III) complexes. The trismalonato and trismaleato complexes dehydrate with almost equal ease but the latter is much less stable to decomposition and yields FeCO₃ below 760 K. The cis-dicarboxylate complexes particularly with maleate(2-) and phthalate(2-) ligands are highly prone to the loss of cyclic anhydrides at moderately raised temperatures. The thermal decomposition of the tris(dicarboxylato)iron(II) to iron oxide was not observed in the investigated temperature range up to 800 K. The dehydration processes generally followed the first or second order mechanism while the third decomposition steps followed either three-dimensional diffusion or contracting volume mechanism.     

Co(II)Schiff碱配合物的合成、氧合反应热力学及热分解动力学的研究

合成了两种新的钴(II)schiff碱配合物水杨醛L-甲硫氨酸-水合钴(II)(1), 邻香兰素L-甲硫氨酸-水合钴(II)(2)。通过元素分析、红外光谱、热分析等测试手段研究了配合物的性质, 并确定了配合物的组成。用气体吸收装置测定配合物在乙腈溶液中不同温度下的饱和吸氧量, 求得氧合反应的平衡常数及热力学参数, 同时探讨了温度和配体结构对配合物氧合性能的影响。用TG-DTG法研究了配合物的热稳定性及非等温热分解动力学, 并采用积分法和微分法相结合的方法,推断了两种配合物的第一步热分解反应机理, 得到了热分解反应动力学参数及其动力学方程。     

Co(II)Schiff碱配合物的合成、氧合反应热力学及热分解动力学的研究

合成了两种新的钴(II)schiff碱配合物水杨醛L-甲硫氨酸-水合钴(II)(1), 邻香兰素L-甲硫氨酸-水合钴(II)(2)。通过元素分析、红外光谱、热分析等测试手段研究了配合物的性质, 并确定了配合物的组成。用气体吸收装置测定配合物在乙腈溶液中不同温度下的饱和吸氧量, 求得氧合反应的平衡常数及热力学参数, 同时探讨了温度和配体结构对配合物氧合性能的影响。用TG-DTG法研究了配合物的热稳定性及非等温热分解动力学, 并采用积分法和微分法相结合的方法,推断了两种配合物的第一步热分解反应机理, 得到了热分解反应动力学参数及其动力学方程。     

α-和β-K6H[GeW9V3O40].xH2O的合成及其^5^1V和^1^8^3W核磁共振研究

本文报道了α-和β-K6H[GeW9V3O40].xH2O的合成及其^5^1V和^1^8^3W NMR研究。^5^1V NMR谱只有一个单峰, ^1^8^3W NMR谱中有两个峰, 相对强度为2:1, 其^2J~w~-~o~-~-~w偶合常数分别为19.35和16.73Hz, 表明其阴离子分别为A型α-和β-Keggin结构, 即三个VO6八面体是角顶共用。