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1.
T-jump/FT-IR spectroscopy was used to study the rapid thermal decomposition activity of [Pb2(TNR)2(CHZ)2(H2O)2]·4H2O and Cd(CHZ)2(TNR)(H2O) under 0.1 MPa Ar atmosphere. The results show that the main gaseous products of [Pb2(TNR)2(CHZ)2(H2O)2]·4H2O are NH3, H2O and HONO, while CO and NO are the major gaseous products of flash pyrolysis of Cd(CHZ)2(TNR)(H2O). Thus Cd(CHZ)2(TNR)(H2O) is not an eco-friendly and chemically compatible primary explosive. Both compounds liberate volatile metal carbonate, oxide and isocyanate compounds. The combustion temperature and products of the two compounds were calculated by Real code. The results of theoretical calculation show that the combustion temperature of [Pb2(TNR)2(CHZ)2(H2O)2].4H2O is higher than that of Cd(CHZ)2(TNR)(H2O), there is no HNCO in the combus- tion products and the amount of NO is less than the experiment result from T-jump/FTIR.  相似文献   

2.
TG-DTG technique and Harcourt-Esson integrated equation were used to study the dehydration process of zinc phosphate tetrahydrate α-Zn3(PO4)2·4H2O nanoparticle and its thermal decomposition kinetics. The results show that there are three stages of dehydration between 300 and 800 K during the thermal decomposition of α-Zn3(PO4)2·4H2O nanoparticle. The first stage is controlled by chemical reaction with an activation energy of 69.48 kJ·mol^-1 and a pre-exponential factor of 1.77×10^6 s^-1. The second is controlled by nucleation and growth with an activation energy of 78.74 kJ·mol^-1 and a pre-exponential factor of 5.86×10^9 s^-1. The third is controlled by nucleation and growth with an activation energy of 141.5 kJ·mol^-1 and a pre-exponential factor of 1.01×10^12 s^-1. The kinetic compensative effects not only exist in Arrhenius equation but also in Harcourt-Esson equation. Activation energy E is dependent on both the decomposition fraction α and temperature T.  相似文献   

3.
邸友莹张剑  谭志诚 《中国化学》2007,25(10):1423-1429
A coordination compound of erbium perchlorate with L-α-glutamic acid, [Er2(Glu)2(H2O)6](ClO4)4·6H2O(s), was synthesized. By chemical analysis, elemental analysis, FTIR, TG/DTG, and comparison with relevant literatures, its chemical composition and structure were established. The mechanism of thermal decomposition of the complex was deduced on the basis of the TG/DTG analysis. Low-temperature heat capacities were measured by a precision automated adiabatic calorimeter from 78 to 318 K. An endothermic peak in the heat capacity curve was observed over the temperature region of 290-318 K, which was ascribed to a solid-to-solid phase transition. The temperature Ttrans, the enthalpy △transHm and the entropy △transSm of the phase transition for the compound were determined to be: (308.73±0.45) K, (10.49±0.05) kJ·mol^-1 and (33.9±0.2) J·K^-1·mol^-1. Polynomial equation of heat capacities as a function of the temperature in the region of 78-290 K was fitted by the least square method. Standard molar enthalpies of dissolution of the mixture [2ErCl3·6H2O(s)+2L-Glu(s)+6NaClO4·H2O(s)] and the mixture {[Er2(Glu)2(H2O)6](ClO4)4·6H2O(s)+6NaCl(s)} in 100 mL of 2 mol·dm^-3 HClO4 as calorimetric solvent, and {2HClO4(1)} in the solution A' at T=298.15 K were measured to be, △dHm,1=(31.552±0.026) kJ·mol^-1, △dHm,2 = (41.302±0.034) kJ·mol^-1, and △dHm,3 = ( 14.986 ± 0.064) kJ·mol^-1, respectively. In accordance with Hess law, the standard molar enthalpy of formation of the complex was determined as △fHm-=-(7551.0±2.4) kJ·mol^-1 by using an isoperibol solution-reaction calorimeter and designing a thermochemical cycle.  相似文献   

4.
Low-temperature heat capacities of octahydrated barium dihydroxide, Ba(OH)2·8H2O(s), were measured by a precision automated adiabatic calorimeter in the temperature range from T=78 to 370 K. An obvious endothermic process took place in the temperature range of 345-356 K. The peak in the heat capacity curve was correspondent to the sum of both the fusion and the first thermal decomposition or dehydration. The experimental molar heat capacifies in the temperature ranges of 78-345 K and 356-369 K were fitted to two polynomials. The peak temperature, molar enthalpy and entropy of the phase change have been determined to be (355.007±0.076) K, (73.506±0.011) kJ·ol^-1 and (207.140±0.074) J·K^-1·mol^-1, respectively, by three series of repeated heat capacity measurements in the temperature region of 298-370 K. The thermodynamic functions, (Hr-H298.15 k )and (Sr-S298.15k), of the compound have been calculated by the numerical integral of the two heat-eapacity polynomials. In addition, DSC and TG-DTG techniques were used for the further study of thermal behavior of the compound. The latent heat of the phase change became into a value larger than that of the normal compound because the melfing process of the compound must be accompanied by the thermal decomposition or dehydration of 71-120.  相似文献   

5.
The thermal decomposition reactions of the complexes cis/trans-[Cu(gly)2]·H2O were studied by TG-DSC methods. The results showed that they have similar decomposition process, which occur in two steps. The first step is the loss of water and the second step is the decomposition of anhydrous complexes. But for cis-[Cu(gly)2]·H2O, the temperature of losing water is higher than that of trans-isomer. Their reaction mechanisms of the two-step decomposition were also proposed.  相似文献   

6.
Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(S) have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141 ±0.095) K, (18.809±0.088) kJ·mol ^-1 and (51.093±0.239) J·K^-1·mol^-1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X=f(T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.  相似文献   

7.
A novel hybrid tungstocuprate ( Ⅱ ) [ Cu (2,2'-bpy) 3 ] 2 H4 [ CuW12O40 ] · 6H2O ( 2,2'-bpy = 2,2'-bipyfidine) was synthesized via hydrothermal method and characterized using elemental analyses, IR, UV, XPS, TG-DSC, EPR, and X-ray single crystal diffraction. The structural analysis shows that the complex consists of an unusual Keggin-type polyoxoanion [ CuW12O40 ]^6- and a pair of chiral complex cations [ Cu(2,2'-bpy) 3 ]^+ together with four protons and six crystallization water molecules, and the Keggin polyoxoanion is connected with [ Cu (2,2'-bpy)3 ]^+v/a multiple C-H…O hydrogen bonds resulting in a dimer.  相似文献   

8.
张建国  张同来  刘艳红 《中国化学》2005,23(10):1403-1406
[Cu(TO)2(H2O)4](PA)2 was prepared by the reaction of aqueous 1,2,4-triazol-5-one (TO) solution with the solution of copper picrate Cu(PA)2 and characterized by elemental analysis, FT IR and X-ray powder diffraction analysis. The title complex has been studied by means of TG-DTG and DSC under conditions of linear temperature increase. The thermal decomposition residues were examined by FT IR analysis. Thermal decomposition mechanism of the title complex was proposed. In the temperature range of 30-680 ℃, the thermal decomposition process was composed of four major stages. The first stage was an endothermic process with the loss of four coordination water molecules. Since the dehydration product was unstable, when it was heated, it would be decomposed much more easily. The second stage was composed of an acute endothermic process and a continued strong exothermic process and the main decomposed residues were CuCO3, Cu(NCO)2 and polymers during this stage. The third stage was a sharp exothermic process, which resulted from the decomposition of the polymer. After the forth stage, the final decomposed residues were certainly copper oxide. The Arrhenius parameters have been also studied on the dehydration process and the first-step exothermic decomposition of [Cu(TO)2(H2O)4](PA)2 using Kissinger's method and Ozawa-Doyle's method. The results using both methods were consistent with each other. The Arrhenius equation can be expressed as in k=24.0-179.8 × 10^3/RT for the dehydration process and in k= 16.7-206.0 × 10^3/RT for the first-step exothermic decomposition, on the basis of the average of Ea and In A through the two methods.  相似文献   

9.
Low-temperature heat capacities of the solid compound Zn(C4H7O5)2(s) were measured in a temperature range from 78 to 374 K, with an automated adiabatic calorimeter. A solid-to-solid phase transition occurred in the temperature range of 295?322 K. The peak temperature, the enthalpy, and entropy of the phase transition were determined to be (316.269±1.039) K, (11.194±0.335) kJ?mol-1, and (35.391±0.654) J?K-1?mol-1, respectively. The experimental values of the molar heat capacities in the temperature regions of 78?295 K and 322?374 K were fitted to two polynomial equations of heat capacities(Cp,m) with reduced temperatures(X) and [X = f(T)], with the help of the least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound, relative to that of the standard reference temperature 293.15 K, were calculated on the basis of the fitted polynomials and tabulated with an interval of 5 K. In addition, the possible mechanism of thermal decomposition of the compound was inferred by the result of TG-DTG analysis.  相似文献   

10.
A transition metal substituted polyoxotungstate, [Cu(en)2(H2O)]2{PW11.5Cu0.5O40[Cu(en)2] }·2H2O
1 based on Keggin frameworks, has bccn hydrothcrmally synthesized and characterized by IR, TGA and single-crystal X-ray structural analysis. It is interesting to find that the structure unit contains two different valence cations, narncly, one [Cu(1)(en)2(H2O)]^+ and one [Cu(2)(en)2(H2O)]^2+. Data for the crystal: orthorhombic system, space group Pbca, a = 21.585(2), b = 20.695(2), c = 26.137(3)A, V = 11675(2)A^3, Z = 8, Mr = 3428.23, Dc = 3.901 g/cm^3, F(000) = 12156,μ(MoKα) = 23.932 mm^-1, the final R = 0.0468 and wR = 0.0969 for 6927 observed reflections (I 〉 2σ(I)).  相似文献   

11.
[Zn(phen)3]·ZTO·6H2O(1) and[Cu(phen)3]·ZTO·6H2O(2) were synthesized by the reaction of Zn(NO3)2·6H2O/Cu(NO3)2·3H2O with 4,4-azo-1H-1,2,4-triazol-5-one(ZTO) and 1,10-phenanthroline(phen). The two compounds were characterized by elemental analysis and IR spectrum analysis, respectively. Compound 1 was also characterized by single crystal X-ray diffraction analysis. For compound 1, the coordination geometry around the Zn2+ is a distorted octahedron, with the bite angles of 76.7(3)°-77.6(4)° for all three phen ligands. Moreover, the thermal behaviors and thermal decomposition kinetics were studied and analyzed. Besides, thermal stability and safety parameters(TSADT, Tb) are 164.7 and 166.4℃ for compound 1, and 149.6 and 150.8℃ for compound 2, respectively.  相似文献   

12.
Thermal decomposition of mixed ligand thymine (2,4-dihydroxy-5-methylpyrimidine) complexes of divalent Ni(II) with aspartate, glutamate and ADA (N-2-acetamido)iminodiacetate dianions was monitored by TG, DTG and DTA analysis in static atmosphere of air. The decomposition course and steps of complexes [Ni(C5H6N2O2)(C4H5NO4)2−(H2O)2]·H2O, [Ni(C5H6N2O2)(C5H7NO4)2−(H2O)2]·H2O and [Ni(C5H6N2O2)(C6H8N2O5)2−(H2O)2]·1.5H2O were analyzed. The final decomposition products are found to be the corresponding metal oxides. The kinetic parameters namely, activation energy (E*), enthalpy (ΔH*), entropy (ΔS*) and free energy change of decomposition (ΔG*) are calculated from the TG curves using Coats–Redfern and Horowitz–Metzger equations. The stability order found for these complexes follows the trend aspartate > ADA > glutamate.  相似文献   

13.
Synthesis and Characterization of Zinc Succinate, Zn(C4H4O4)   总被引:3,自引:0,他引:3  
Introduction  Succinateion (C4H4O4) 2 -(—OOCCH2 CH2 COO— )isaversatileligandsinceeachofthefourterminalcarboxyloxygensisabletoparticipateincoordinationtocentralmetalatom(s)inadditiontotheflexibilityoftheC—Cbone .Suchcoordinatingversatilityhasbeenreflectedinseve…  相似文献   

14.
金属磷酸盐材料在吸附、离子交换、离子传导和催化剂方面有潜在的应用前景[1~5]. 近年来, 通过水热反应合成了一些A-V-P-O化合物. 在这些化合物中, A一般为碱金属或有机阳离子, 如层状结构的[H2N(C4H8)2NH2][(VO)4(OH)4(PO4)2][6] 和[H2N(C2H4)3NH2][(VO)8(HPO4)3(PO4)4*(OH)2]*2H2O[6], 一维链状结构的 [H2NCH2CH2NH3(VO)(PO4)][7], 手性双螺旋结构的 [(CH3)2NH2]K4[(VO)10(H2O)2(OH)4(PO4)7]*H2O[8]以及具有三维骨架结构的化合物 [H3N(CH2)3NH3K(VO)3(PO4)3][9], [H3N(CH2)3NH3]2[V(H2O)2(VO)6(OH)2(HPO4)3(PO4)5]*3H2O[10]和[H3N(CH2)2NH3][(VO)3(H2O)2(PO4)2(HPO4)4][11].  相似文献   

15.
多金属氧酸盐 (也称金属 -氧簇 )由于在催化、材料及医药等领域的应用日益广泛而备受关注 .近年来 ,一些新颖的非经典结构的化合物不断被合成出来 .如带二帽的 Keggin结构化合物 [V15O4 2 ]9- [1] ,[PV14 O4 2 ]9- [2 ] ,[As V14 O4 2 ]9- [3 ] ,[{ Mo8V7O4 2 } 2 ]14 - [4 ] ,  相似文献   

16.
The hexaaquacobalt(II)bis(phthalhydrazidato)tetrahydrate, [Co(H2O)6](C8N2O2H5)2·4H2O is examined using single crystal X-ray diffraction analysis. The crystals are triclinic, space group , with a = 9.757(1), b = 10.955(2), c = 11.106(1),  = 100.79(2), β = 90.35(3), γ = 91.54(1) and Z = 2. In [Co(H2O)6](C8N2O2H5)2·4H2O, the cobalt(II) is coordinated by six water ligands and the [Co(H2O)6]2+ is associated with the two O-deprotonated phthalhydrazidato ions only by hydrogen bonds. The infrared and Raman spectra of phthalhydrazide (PH) and infrared spectra of deuterated derivative phthalhydrazide (PD) and of [Co(H2O)6](C8N2O2H5)2·4H2O are reported. The theoretical wavenumbers, infrared intensities and Raman scattering activities have been calculated using density functional (B3LYP) method with the 6-311++G(d,p) basis set. The calculated potential energy distribution has proved to be of great help in assigning the spectra PH, its deuterated derivative and [Co(H2O)6](C8N2O2H5)2·4H2O. The results from natural bond orbital (NBO) analysis for keto-hydroxy form of PH are presented.  相似文献   

17.
Chromium(Ⅲ) is one essential nutrient that has been implicated as glucose tolerant factor(GTF) in the maintenance of normal carbohydrate and lipid metabolism. Schiff base complexes of chromium (Ⅲ) such as N,N' -ethylenebis (Salicylideneiminato) diaquochromium (Ⅲ) chloride[Cr(Salen)(H2O)2]Cl as a new kind of GTP model was shown to reduce the symptoms of diabetes significantly, hyperglycemia and cholesterol in diabetic rates[l]. After studied the decomposition and characterization of[Cr(Salen)(H2O)2]Cl[2], a new confound of[Cr(Salen)(H2O)2]BPh4 is prepared and its transfer Gibbs energies(Δtr Go) from water to strait-chain Alkanols is studied in order to understand the thermodynamic properties of[Cr(Salen)(H2O)2]+ in different solvents.  相似文献   

18.
Two new polyoxometalate(POM)-based hybrid compounds, [Cu(en)][H4Mo4O16]0.5(1)(en=ethylene- diamine) and [Ag(3-C5H6N2)2][H2PMo12O40](2)(3-C5H6N2=3-aminopyridine), containing different transition metal-amine subunits were hydrothermally synthesized and characterized by elemental analyses, infrared spectroscopy and single-crystal X-ray diffraction. For compound 1, each [H4Mo4O16]4-(Mo4O16) cluster was linked to four neighboring Mo4O16 clusters through four [Cu(en)]2+ subunits to yield a (2,4)-connected 2D layer, which was further extended to a 3D supramolecular network via hydrogen bonding interactions. For compound 2, the adjacent [H2PMo12O40]- clusters were bridged by [Ag(3-C5H6N2)2]+ subunits to generate a 1D chain. The electrochemical behaviors and the photocatalytic activities of compounds 1 and 2 were studied in detail.  相似文献   

19.
Recently, there has been considerable interest in cyano-bridged lanthanide(Ⅲ) hexacyanometalate(Ⅲ) complexes LnM(CN)6·nH2O (M=Fe, Cr and Co) because of their potential as catalytic, semiconductive, and magnetic materials.[1-8] In this study, we employed N,N-dimethylformamide (DMF) as a hybrid ligand to construct a bimetallic complex[Eu(DMF)4(H2O)2Cr(CN)6]·H2O. It was synthesized as yellow crystals by the self-assembly of anhydrous EuCl3 and (Bu4N)3[Cr(CN)6] in MeOH and DMF. Single-crystal X-ray diffraction analysis shows that it consists of a cyano-bridged chain structure. The Eu atom is eight-coordinate with a distorted bicapped square antiprism geometry. Six oxygen atoms of two water molecules and four DMF molecules and two nitrogen atoms of the bridging CN ligands are bound to Eu with the Eu-O distance ranging from 2.368(7) to 2.447(8) Å. The bridging cyanides coordinate to the Europium(Ⅲ) ion[N(l)-Eu=2.543(9) Å and N(3)-EuA=2.543(8) Å] in a bent fashion with the bond angles of 164.0(9) for C(1)-N(1)-Nd and 155.1(7)。for C(3)-N(3)-EuA (A denotes the symmetry transformation:-x+l,y-l/2,-z+3/2). Each Cr(CN)6 coordinates to two Eu(Ⅲ) ions using two cis cyanide ligands, while each Eu(DMF)4(H2O)2 group connects two Cr(CN)6 moieties in a cis fashion, giving rise to an unprecedented chain structure. Crystal data:monoclinic, space group P21/c, a=13.151(2), b=12.905(2), c=19.186(2) Å, β=109.70(1)°, V=3065.5(7) Å3,Z=4, ρobs=1.531 Mg m-3, S=1.024,R1=0.0540, Rw=0.1616.  相似文献   

20.
1-Methylpiperazine was employed to crystallize with 2,4-dihydroxybenzoic acid and 1,8-naphthalene acid, affording two multi-component hydrogen-bonding salts [(C5H14N2)2+·(C7H5O4)2-·H2O](1) and [(C5H14N2)2+(C12H6O4)2ˉ·2H2O](2). These two forms of salts are both monoclinic systems with space group P21/c(14). The lattice parameters of salts 1 and 2 are a=1.32666(10) nm, b=0.90527(7) nm, c=1.67107(13) nm, β=103.125(1)° and a=1.4950(2) nm, b=0.75242(15) nm, c=1.6563(3) nm, β=92.834(2)°, respectively. Expected classical hydrogen bonds N―H…O and O―H…O appear in the chargetransfer salts, and asymmetric units of these two forms both contain water molecules which play a significant role in building novel supramolecular architectures. Robust hydrogen-bond interactions between 1-methylpiperazine and aromatic acid provide sufficient driving force to direct the two crystals to three-dimensional structures. Weak interactions C―H…O emerging in salts 1 and 2 further enhance their crystal structures. As a consequence, hydrogen-bonding interactions in these compounds afford diverse 3D net supramolecular architectures. Thermal stability of these compounds was investigated by thermogravimetric analysis(TGA).  相似文献   

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