Calorimetric study and thermal analysis of [Gd4/3Y2/3(Gly)6(H2O)4](ClO4)6·5H2O and [ErY(Gly)6(H2O)4](ClO4)6·5H2O (Gly: glycin)

Two solid-state coordination compounds of rare earth metals with glycin, [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O and [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O were synthesized. The low-temperature heat capacities of the two coordination compounds were measured with an adiabatic calorimeter over the temperature range from 78 to 376 K. [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O melted at 342.90 K, while [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O melted at 328.79 K. The molar enthalpy and entropy of fusion for the two coordination compounds were determined to be 18.48 kJ mol⁻¹ and 53.9 J K⁻¹ mol⁻¹ for [Gd_4/3Y_2/3(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O, 1.82 kJ mol⁻¹ and 5.5 J K⁻¹ mol⁻¹ for [ErY(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O, respectively. Thermal decompositions of the two coordination compounds were studied through the thermogravimetry (TG). Possible mechanisms of the decompositions are discussed.     

Non-equivalent water molecules in [Ni(H2O)6](ClO4)2 and in [Ni(D2O)6](ClO4)2 in the thermogravimetric investigations

The thermal decomposition of [Ni(H₂O)₆](ClO₄)₂ and [Ni(D₂O)₆](ClO₄)₂ were studied by thermogravimetric analysis (TG) and simultaneous differential thermal analysis (SDTA) at a constant heating rate. The gaseous products of the decomposition were on-line identified by a quadrupole mass spectrometer (QMS). In both cases the process of decomposition starts at ca. 410 K and is connected with removal of water molecules in a stepwise way; at the beginning the first water molecule is lost, then the second and at higher temperature the third one. The rest of the water molecules are lost in the temperature region of ClO₄⁻ decomposition. The energy of activation of the process was calculated in both cases.     

[Gd2(Gly)6(H2O)4](ClO4)6(H2O)5的合成、晶体结构与热化学研究

利用微波技术合成了配合物[Gd₂(Gly)₆(H₂O)₄](ClO₄)₆(H₂O)₅, 进行了化学成分分析、红外表征和热重分析. 应用X衍射仪测定其晶体结构, 该晶体为一维链结构, 属三斜晶系, P 空间群, 晶胞参数: a＝1.1569(17) nm, b＝1.4138(2) nm, c＝1.5642(2) nm, α＝96.910(2)°, β＝102.735(2)°, γ＝105.512(2)°, V＝2.3606(6) nm³, Z＝2, D_c＝2.144 g•cm^－3. 采用精密溶解-反应量热计, 通过设计热化学循环, 计算出了该配合物的标准摩尔生成焓为 －(7960.73±3.23) kJ•mol^－1.     

Low-temperature heat capacity and standard enthalpy of formation of neodymium glycine perchlorate complex [Nd2(Gly)6(H2O)4](ClO4)6·5H2O

Rare-earth perchlorate complex coordinated with glycine [Nd₂(Gly)₆(H₂O)₄](ClO₄)₆·5H₂O was synthesized and its structure was characterized by using thermogravimetric analysis (TG), differential thermal analysis (DTA), chemical analysis and elementary analysis. Its purity was 99.90%. Heat capacity measurement was carried out with a high-precision fully-automatic adiabatic calorimeter over the temperature range from 78 to 369 K. A solid-solid phase transformation peak was observed at 256.97 K, with the enthalpy and entropy of the phase transformation process are 4.438 kJ mol⁻¹ and 17.270 J K⁻¹ mol⁻¹, respectively. There is a big dehydrated peak appears at 330 K, its decomposition temperature, decomposition enthalpy and entropy are 320.606 K, 41.364 kJ mol⁻¹ and 129.018 J K⁻¹ mol⁻¹, respectively. The polynomial equations of heat capacity of this compound in different temperature ranges have been fitted. The standard enthalpy of formation was determined to be −8023.002 kJ mol⁻¹ with isoperibol reaction calorimeter at 298.15 K.     

Structure of Ba Na Ethylenediaminetetraacetatocobaltate(III) Perchlorate, Na[Ba6(H2O)25][Co(Edta)]4(ClO4)9 · 5H2O

Crystals with uncommon composition NaBa₆[Co(Edta)]₄(ClO₄)₉ · 30H₂O (Edta⁴⁻ is ethylenediaminetetraacetic acid anion) were obtained with the following unit cell parameters: a = 14.8513(9) Å, b = 26.2361(15) Å, c = 15.1789(9) Å, α = 91.661(7)°, β = 113.035(7)°, γ = 89.897(7)°, space group P1¯. Each complex anion [Co(Edta)]⁻ is bonded through the carboxyl O atoms to five Ba atoms to give three-dimensional framework in a crystal. One perchlorate ion forms Ba-O-Cl-O-Ba bridge between the Ba atoms; four ClO ₄ ⁻ ions are isolated, while the remaining four ions act as monodentate ligands at the Ba atoms. The water molecules (25 in sum) complete the coordination sphere of the Ba atoms to eight-, nine-, or ten-vertex polyhedron. Four water molecules are in the closest surrounding of the Na atom, one H₂O molecule is isolated.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 8, 2005, pp. 590–595.Original Russian Text Copyright © 2005 by Zabel, Poznyak, Pawlowski.     

Strukturchemie titanorganischer verbindungen: Molekül- und kristallstruktur von [{(π-C5H5)2Ti(H2O)}2O](ClO4)2 · 2 H2O

(π-C₅H₅)₂TiCl₂ and cobaltous perchlorate react in aqueous solution to give [{(π-C₅H₅)₂Ti(H₂O)}₂O](ClO₄)₂ · 2 H₂O (I). Compound I crystallizes in the orthorhombic space group Fdd2 with Z 8 and lattice parameters a 28.893(5), b 17.433(4), c 10.312(3) Å. Results of an X-ray analysis of I (R 0.061): the (crystallographic) symmetry of the complex cation is C₂-2; Ti exhibits pseudotetrahedral coordination with a water molecule as one of the ligands; Ti—μ-O distance 1.83 Å; Ti—μ-O—Ti angle 176°; the geometry of the (π-C₅H₅)₂Ti unit in I corresponds closely to that in (π-C₅H₅)₂TiCl₂.     

A novel three-dimensional malonate-bridged complex {[Cu4(4,4′- bpy)8(mal)2(H2O)4](ClO4)2(H2O)4(CH3OH)2}n

A novel malonate-bridged copper (II) compound of formula {[Cu₄(4,4′-bpy)₈(mal)₂(H₂O)₄](ClO₄)₂(H₂O)₄(CH₃OH)₂}_n (4,4′-bpy = 4,4′-bipyridine; mal = malonate dianion) has been prepared and structurally characterized by X-ray crystallography. This compound exhibits a novel three-dimensional network being composed of Cu-4,4′-bipyridine layers which are pillared by malonate bridge ligands. The copper(II) ions has two different coordination environment.     

用T-jump/FTIR研究MnCP、NiCP和PbCP的快速热分解(英)

0IntroductionCarbohydrazideisahydrazinederivativewithwhitecrystalofstrongreducingbehaviors.Becauseithasmanycoordinationatoms(fournitrogenatomsandoneoxygenatom),carbohydrazidecan,therefore,beusedasmultidentateligand.Itscoordinationcom鄄poundiswidelyusedint…     

[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.     

Melting and thermal decomposition of [Ni(H2O)6](NO3)2

The two-stage melting process and the thermal decomposition of [Ni(H₂O)₆](NO₃)₂ was studied by DSC, DTA and TG. The first melting point at 328 K is connected with the small and the second melting point at 362 K with the large enthalpy and entropy changes. The thermal dehydration process starts just above ca. 315 K and continues up to ca. 500 K. It consists of three well-separated stages, but the sample mass loss at each stage depends on the experimental regime. However, irrespective of the chosen regime, the total of registered mass losses in stage one and two amounts to three H₂O molecules per one [Ni(H₂O)₆](NO₃)₂ molecule. The remaining three H₂O molecules are gradually freed in the temperature range of 440–500 K in the third stage of the dehydration. Above 580 K, anhydrous Ni(NO₃)₂ decomposes into NO and NiO. The gaseous products were identified by quadrupole mass spectrometer (QMS), and the solid product was identified by X-ray diffraction (XRD) analysis.     

Synthesis, heat capacity and enthalpy of formation of [Ho2(l-Glu)2(H2O)8](ClO4)4·H2O

A complex of holmium perchlorate coordinated with l-glutamic acid, [Ho₂(l-Glu)₂(H₂O)₈](ClO₄)₄·H₂O, was prepared with a purity of 98.96%. The compound was characterized by chemical, elemental and thermal analysis. Heat capacities of the compound were determined by automated adiabatic calorimetry from 78 to 370 K. The dehydration temperature is 350 K. The dehydration enthalpy and entropy are 16.34 kJ mol⁻¹ and 16.67 J K⁻¹ mol⁻¹, respectively. The standard enthalpy of formation is −6474.6 kJ mol⁻¹ from reaction calorimetry at 298.15 K.     

三维超分子[Ni(hmt)2(SCN)2(H2O)2][Ni(SCN)2(H2O)4](H2O)2的自组装,晶体结构及磁性质(hmt=六次甲基四胺)

Compound [Ni(hmt)₂(SCN)₂(H₂O)₂][Ni(SCN)₂(H₂O)₄](H₂O)₂ (hmt=hexamethylenetetramine) was pre-pared and structurally characterized by means of X-ray single crystal diffraction. The two neutral units [Ni(hmt)₂(SCN)₂(H₂O)₂] and [Ni(SCN)₂(H₂O)₄] are joined together through hydrogen bonds N…H-O, O…H-O and S…H-O. In the solid state, the compound has three-dimensional network structure. The determination of its variable-temperature magnetic susceptibilities (5～300K) shows that the magnetic behavior obeys the Curie-Weiss law over the whole temperature ranges.     

[Cu(DMTZB)_4](ClO_4)_2的合成及晶体结构(DMTZB=3,3-二甲基-(1H-1,2,4-三唑)-2-丁酮)

［Ｃｕ（ＤＭＴＺＢ）４］（ＣｌＯ４）２的合成及晶体结构（ＤＭＴＺＢ＝３，３－二甲基－（１Ｈ－１，２，４－三唑）－２－丁酮）顾建胜李宝龙＊卞国庆（苏州大学化学系苏州２１５００６）郁开北（中科院成都分院分析测试中心成都６１００４１）关键词三唑铜配合物晶体...     

Low-temperature heat capacity and thermodynamic properties of crystalline [Re2(Ala)4(H2O)8](ClO4)6 (Re = Eu, Er; Ala = alanine)

[Re₂(Ala)₄(H₂O)₈](ClO₄)₆ (Re=Eu, Er; Ala=alanine) were synthesized, and the low-temperature heat capacities of the two complexes were measured with a high-precision adiabatic calorimeter over the temperature range from 80 to 370 K. For [Eu₂(Ala)₄(H₂O)₈](ClO₄)₆, two solid–solid phase transitions were found, one in the temperature range from 234.403 to 249.960 K, with peak temperature 243.050 K, the other in the range from 249.960 to 278.881 K, with peak temperature 270.155 K. For [Er₂(Ala)₄(H₂O)₈](ClO₄)₆, one solid–solid phase transition was observed in the range from 270.696 to 282.156 K, with peak temperature 278.970 K. The molar enthalpy increments, ΔH_m, and entropy increments,ΔS_m, of these phase transitions, were determined to be 455.6 J mol⁻¹, 1.87 J K⁻¹ mol⁻¹ at 243.050 K; 2277 J mol⁻¹, 8.43 J K⁻¹ mol⁻¹ at 270.155 K for [Eu₂(Ala)₄(H₂O)₈](ClO₄)₆; and 4442 J mol⁻¹, 15.92 J K⁻¹ mol⁻¹ at 278.970 K for [Er₂(Ala)₄(H₂O)₈](ClO₄)₆. Thermal decompositions of the two complexes were investigated by use of the thermogravimetric (TG) analysis. A possible mechanism for the thermal decomposition is suggested.     

Crystal Structure of (H3O)4[(C2H5)4N]6 [Th2Cl4(H2O)12O]3[Re4Se4(CN)12]4

Crystals of the rhenium cluster complex (H₃O)₄[(C₂H₅)₄N]₆[Th₂Cl₄(H₂O)₁₂O]₃[Re₄Se₄(CN)₁₂]₄ are obtained in an acidic (HCl) aqueous solution by the reaction of cluster salt K₄[Re₄Se₄(CN)₁₂]·6H₂O with ThCl₄ and (C₂H₅)₄NCl. Single crystal X-ray analysis shows that the title compound is ionic and crystallizes in the cubic crystal system (a = 22.7322(3) ?, V = 11746.93(27) ?³, Z = 2, I4 3m space group, R = 0.0350). It contains [Th₂Cl₄(H₂O)₁₂O]²⁺ cations with two thorium atoms bonded to each other through the bridging oxygen atom forming an angle of 180° in the structure.     

Complexes of N,N′,N′′-tris(2-hydroxypropyl)-1,4,7-triazacyclononane (L): Structures of [CuL](ClO4)(NO3), [CoL](ClO4)2, [ZnL](ClO4)2 and the catalytic activity of [MnL](ClO4)2 towards olefin epoxidation with hydrogen peroxide

Complexes of N,N′,N′′-tris(2-hydroxypropyl)-1,4,7-triazacyclononane (L), [CuL](ClO₄)(NO₃) (1), [CoL](ClO₄)₂ (2), [ZnL](ClO₄)₂ (3) and [MnL](ClO₄)₂ (4), have been synthesized and characterized on the basis of elemental analysis, electrospray ionization mass spectrometry, UV–Vis measurements and cyclic voltammetry. Crystal structures of the former three complexes, characterized by X-ray crystallography, show that these complexes are monoclinic with space group P2₁/n and P2₁/c. Each metal central in the complexes is six-coordinate with three N atoms of the macrocycle and three O atoms from the pendant hydroxypropyl arms, forming a distorted octahedral configuration. [MnL](ClO₄)₂ (4) is employed as catalyst in olefin epoxidation with H₂O₂. The final results indicate that complex (4) has good catalytic activity towards olefin epoxidation. Under mild conditions, the olefin conversion is moderate and epoxidation selectivity is 95–100%.     

Phase transitions and molecular motions in [Ni(ND3)6](ClO4)2

[Ni(ND₃)₆](ClO₄)₂ has three solid phases between 100 and 300 K. The phase transitions temperatures at heating (T_C1^h=164.1 K and T_C2^h=145.1 K) are shifted, as compared to the non-deuterated compound, towards the lower temperature of ca. 8 and 5 K, respectively. The ClO₄⁻ anions perform fast, picosecond, isotropic reorientation with the activation energy of 6.6 kJ mol⁻¹, which abruptly slow down at T_C1^c phase transition, during sample cooling. The ND₃ ligands perform fast uniaxial reorientation around the Ni-N bond in all three detected phases, with the effective activation energy of 2.9 kJ mol⁻¹. The reorientational motion of ND₃ is only slightly distorted at the T_C1 phase transition due to the dynamical orientational order-disorder process of anions. The low value of the activation energy for the ND₃ reorientation suggests that this reorientation undergoes the translation-rotation coupling, which makes the barrier to the rotation of the ammonia ligands not constant but fluctuating. The phase polymorphism and the dynamics of the molecular reorientations of the title compound are similar but not quite identical with these of the [Ni(NH₃)₆](ClO₄)₂.     

Phase polymorphism of [Zn(DMSO)6](ClO4)2 studied by differential scanning calorimetry

Four solid phases of [Zn(DMSO)₆](ClO₄)₂ have been detected by differential scanning calorimetry (DSC). Specifically, the phase transitions were detected between: metastable phase KII ↔ supercooled phase K0 at , stable phase KIb ↔ stable phase KIa at , stable phase KIa ↔ stable phase K0 at . At T_m2 = 389 K crystals partially and at T_m1 = 465 K completely melts. From the entropy change values it was concluded that the phases: K0 and K0′ are the orientationally dynamically disordered phases, so called ODDIC crystals, and phases KIa, KIb and metastable KII are dynamically ordered but with some degree of positional disorder.     

Synthesis, structure, and properties of [Re2(HPO4)2(H2PO4)2(H2O)2] · 4H2O

The complex [Re₂(HPO₄)₂(H₂PO₄)₂(H₂O)₂] · 4H₂O (I) was synthesized and investigated by conductometric, potentiometric, electronic and vibration spectroscopic methods. Thermal behavior of the title compound was studied and its molecular structure was determined from X-ray diffraction data. In the dimeric neutral complex, the bridging pairs of the hydrophosphate and dihydrophosphate groups close four five-membered Re-O-P-O-Re chelate rings. The O atom of water molecule occupies the axial position in the metal coordination polyhedron. The Re-Re distance 2.2168(8) ? corresponds to quadruple bond. Original Russian Text ? A.V. Shtemenko, V.G. Stolyarenko, K.V. Domasevich, 2007, published in Koordinatsionnaya Khimiya, 2007, Vol. 33, No. 2, pp. 83–88.     

一个新的Tutton盐Na2[Co(H2O)6](SO4)2的结构与性能研究

采用溶液法合成了一个新的Tutton盐Na2[Co(H2O)6](SO4)2通过红外光谱和X-射线单晶衍射对其进行了表征.晶体结构分析表明该化合物晶体属单斜晶系,P21/c空间群,晶胞参数:a=0.6185(2)nm,b=1.2334(3)um,c=0.9137(1)nm,β=105.775(1)°,V=0.67078(2)nm3,Z=2.固体粉末紫外可见透射光谱是不连续的,具有较高的透过率和较窄的带宽(300～450 nm).用循环伏安法研究了化合物的电化学性质,发现Na2[Co(H2O)6](SO4)2掺杂氢氧化镍电极片的氧化还原峰电流均有较大提高,电极反应活性明显增加.