The treatment of RECl3.xH2O (RE = Ho, Er, Tm, Yb, Lu; x = 3-4) with sodium diethyldithiocarbamate (NaEtEdtc-3H2O) and 1,10-phenanthroline hydrate (o-phen.H2O) in absolute ethanol yielded five ternary solid compl...The treatment of RECl3.xH2O (RE = Ho, Er, Tm, Yb, Lu; x = 3-4) with sodium diethyldithiocarbamate (NaEtEdtc-3H2O) and 1,10-phenanthroline hydrate (o-phen.H2O) in absolute ethanol yielded five ternary solid complexes RE(EtEdtC)a(phen). IR spectra of the complexes showed that RE^3+ coordinated to two sulfur atoms in NaEt2dtc and two nitrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.展开更多
Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(HSal)3·2H2O(RE = La...Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(HSal)3·2H2O(RE = La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE^3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes,△c U, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, △cH^θm, and standard molar enthalpies of formation, △fH^θm, were calculated.展开更多
The combustion energy has been determined for the nine solid complexes of rare earth perchlorate with glycine and imidazole using a rotatingbomb calorimeter.The standard enthalpy of combustion,H0 -c,coor(s), and stan...The combustion energy has been determined for the nine solid complexes of rare earth perchlorate with glycine and imidazole using a rotatingbomb calorimeter.The standard enthalpy of combustion,H0 -c,coor(s), and standard enthalpy of formation,H0 -f,coor(s), for these complexes have been calculated. From the plot of standard enthalpy of formation versus atomic number of the elements in lanthanide series the tripartite effect regularity was observed and the unknown standard enthalpy of formation for similar complexes,Ce(Gly)4(Im)(ClO4)32H2O and Pm(Gly)4(Im)(ClO4)32H2O,can be estimated according to the figure.展开更多
The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt_2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title ...The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt_2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title complex was identified as the general formula of Dy(Et_2dtc)_3(phen) by chemical and elemental analyses. IR spectrum of the complex shows that the Dy^(3+) coordinated with six sulfur atoms of three NaEt_2dtc and two nitrogen atoms of phen. It is assumed that the coordination number of Dy^(3+) is eight.The enthalpy change of liquid-phase reaction of formation, Δ_rH~θ_m(l), is determined as (-19.091±0.015) kJ·mol^(-1) at 298.15 K by a microcalorimeter, and the enthalpy change of the solid-phase reaction of formation, Δ_rH~θ_m(s), is calculated as (139.641±0.482) kJ·mol^(-1) on the basis of a thermochemical cycle. The thermodynamic of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, Δ_cU, is determined as (-16730.21±9.25) kJ·mol^(-1) by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpies of combustion, Δ_cH~θ_m, and standard enthalpies of formation, Δ_fH~θ_m, are calculated as (-16749.42±9.25) kJ·mol^(-1) and (-2019.68±10.19) kJ·mol^(-1), respectively.展开更多
The combustion energies have been determined for the solid complexes, RE(Met) 4(NO 3) 3·6H 2O(RE=La~Nd, Sm~Lu), by means of a rotating bombicalorimeter. The standard enthalpies of combustion, ΔH ...The combustion energies have been determined for the solid complexes, RE(Met) 4(NO 3) 3·6H 2O(RE=La~Nd, Sm~Lu), by means of a rotating bombicalorimeter. The standard enthalpies of combustion, ΔH c,coor(s) , and standard enthalpies of formation, ΔH f,coor(s) , have been calculated for these complexes. It has been found that “tetrad effect” regularity was observed for the fact that the standard enthalpies of formation are ploted against the atomic numbers of the elements in lanthanide series. The results show that a certain amount of covalency is present for chemical bond between the rare earth cation and methionine.展开更多
The combustion characteristics and kinetics of anthracite,pine sawdust and their blends were investigated under combustion condition by thermogravimetric analysis,respectively.The fractions of pine sawdust in the blen...The combustion characteristics and kinetics of anthracite,pine sawdust and their blends were investigated under combustion condition by thermogravimetric analysis,respectively.The fractions of pine sawdust in the blended samples were set to be 30%,50%,and 80%.The results showed that the ignition and burnout temperatures of pine sawdust were lower and the maximum combustion rate was higher than those of anthracite.With the increase of pine sawdust content,the ignition temperature and burnout temperature of the blends decreased,while the maximum mass loss rate and the combustible index of the blends increased;that is,the comprehensive combustion property became better.The kinetic parameters for the blends combustion under air condition were calculated based on experimental results using Coats-Redfern model.When the pine sawdust content varied in the range of 30%-80%,the combustion processes of these blends could be divided into two stages and the combustion reactions belong to the first-order reaction.The values of apparent activation energy at two individual stages decreased from 68.78to47.28kJ·mol-1 and from 113.53 to 46.43kJ·mol-1,respectively.展开更多
The constant-volume combustion energy, △cU (DADE, s, 298.15 K), the thermal behavior, and kinetics and mechanism of the exothermic decomposition reaction of 1,1-diamino-2,2-dinitroethylene (DADE) have been invest...The constant-volume combustion energy, △cU (DADE, s, 298.15 K), the thermal behavior, and kinetics and mechanism of the exothermic decomposition reaction of 1,1-diamino-2,2-dinitroethylene (DADE) have been investigated by a precise rotating bomb calorimeter, TG-DTG, DSC, rapid-scan fourier transform infrared (RSFT-IR) spectroscopy and T-jump/FTIR, respectively. The value of △cHm (DADE, s, 298.15 K) was determined as (-8518.09±4.59) j·g^-1. Its standard enthalpy of combustion, △cU (DADE, s, 298.15 K), and standard enthalpy of formation, △fHm (DADE, s, 298.15 K) were calculated to be (-1254.00±0.68) and (- 103.98±0.73) kJ·mol^-1, respectively The kinetic parameters (the apparent activation energy Ea and pre-exponential factor A) of the first exothermic decomposition reaction in a temperature-programmed mode obtained by Kissinger's method and Ozawa's method, were Ek=344.35 kJ·mol^-1, AR= 1034.50 S^-1 and Eo=335.32 kJ·mol^-1, respectively. The critical temperatures of thermal explosion of DADE were 206.98 and 207.08 ℃ by different methods. Information was obtained on its thermolysis detected by RSFT-IR and T-jump/FTIR.展开更多
The constant-volume combustion energy, cUD(GUDN, s, 298.15 K), enthalpy of solution in acetic ether, solmHQD and kinetic behavior of the exothermic decomposition reaction of the title compound (GUDN) are deter-mined b...The constant-volume combustion energy, cUD(GUDN, s, 298.15 K), enthalpy of solution in acetic ether, solmHQD and kinetic behavior of the exothermic decomposition reaction of the title compound (GUDN) are deter-mined by a precise rotating bomb calorimeter, a Calvet microcalorimeter and DSC, respectively. Its standard en-thalpy of combustion, cmHQD (GUDN, s, 298.15 K), standard enthalpy of formation, fHQDm (GUDN, s, 298.15 K) and kinetic parameters of the exothermic main decomposition reaction in a temperature-programmed mode [the apparent activation energy (aE) and pre-exponential factor (A)] are calculated. The values of cUD (GUDN, s, 298.15 K), cmHQD (GUDN, s, 298.15 K), fmHQD(GUDN, s, 298.15 K) and solmHQD of GUDN are (-7068.64±2.37) J·g-1, (-1467.66±0.50) kJ·mol-1, (-319.76±0.58) kJ·mol-1 and (165.737±0.013) kJ·mol-1, respectively. The kinetic model function in integral form and the value of aEand A of the exothermic main decomposition reaction of GUDN are 220.20 kJ·mol-1 and 1021.18 s-1, respectively. The critical temperature of thermal explosion of GUDN is 217.6 ℃展开更多
The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt2dtc?3H2O), 1,10-phenanthroline (o-phen?H2O) and hydrated neodymium chloride in absolute ethanol. The title complex was identifi...The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt2dtc?3H2O), 1,10-phenanthroline (o-phen?H2O) and hydrated neodymium chloride in absolute ethanol. The title complex was identified as the general formula of Nd(Et2dtc)3(phen) by chemical and elemental analyses. IR spectrum of the complex showed that the Nd3+ coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of o-phen. It was assumed that the coordination number of Nd3+ is eight.The enthalpy change of liquid-phase reaction of formation, ?rHm (l), was determined as (-12.274±0.050) kJ?mol-1 at 298.15 K by a microcalorimeter, the Θ enthalpy change of the solid-phase reaction of formation, ?rHm (s), was calculated as (149.069±0.314) kJ?mol-1 Θ on the basis of a thermochemical cycle. The thermodynamics of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, ?cU , was deter- mined as (-18674.22±8.33) kJ?mol-1 by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, ?cHm , and standard enthalpy of formation, ?fHm , were calculated as (-18693.43±8.33) kJ?mol-1 Θ Θ and (-47.03±9.17) kJ?mol-1, respectively.展开更多
基金[This work was financially supported by the Natural Science Foundation of China (No. 20171036), the Natural Science Foundation of Shaanxi Province (Nos. 01JK229, FF02328 and 05JK291) and Postgraduate Foundation of China.]
文摘The treatment of RECl3.xH2O (RE = Ho, Er, Tm, Yb, Lu; x = 3-4) with sodium diethyldithiocarbamate (NaEtEdtc-3H2O) and 1,10-phenanthroline hydrate (o-phen.H2O) in absolute ethanol yielded five ternary solid complexes RE(EtEdtC)a(phen). IR spectra of the complexes showed that RE^3+ coordinated to two sulfur atoms in NaEt2dtc and two nitrogen atoms in o-phen. The constant-volume energies of combustion of the complexes have been determined by a precise rotating-bomb calorimeter at 298.15 K. The standard enthalpies of combustion and standard enthalpies of formation were calculated.
基金Project supported bythe Northwest University (02NW02) and the Educational Committee of Shaanxi Province (05JC31)
文摘Five solid rare earth salicylate complexes were synthesized by low hydrated lathanide chloride and salicylic acid. The complexes in this experiment were identified as the general formula RE(HSal)3·2H2O(RE = La, Ce, Pr, Nd, Sm) by elemental analysis and EDTA volumetric analysis. IR spectra of the complexes show that carboxyl of salicylic acid coordinates to RE^3+ ions. Electrochemical behaviors of the complexes on the glass-carbon electrode were researched with cyclic voltammetry (CV). It is indicated that the electrochemical process of the complexes is a one-electron redox process and the electrochemical reversibility of complexes is less than that of the lanthanide chlorides. The constant-volume combustion energies of complexes,△c U, were determined with a precise rotating-bomb calorimeter at 298.15 K. Their standard molar enthalpies of combustion, △cH^θm, and standard molar enthalpies of formation, △fH^θm, were calculated.
文摘The combustion energy has been determined for the nine solid complexes of rare earth perchlorate with glycine and imidazole using a rotatingbomb calorimeter.The standard enthalpy of combustion,H0 -c,coor(s), and standard enthalpy of formation,H0 -f,coor(s), for these complexes have been calculated. From the plot of standard enthalpy of formation versus atomic number of the elements in lanthanide series the tripartite effect regularity was observed and the unknown standard enthalpy of formation for similar complexes,Ce(Gly)4(Im)(ClO4)32H2O and Pm(Gly)4(Im)(ClO4)32H2O,can be estimated according to the figure.
文摘The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt_2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title complex was identified as the general formula of Dy(Et_2dtc)_3(phen) by chemical and elemental analyses. IR spectrum of the complex shows that the Dy^(3+) coordinated with six sulfur atoms of three NaEt_2dtc and two nitrogen atoms of phen. It is assumed that the coordination number of Dy^(3+) is eight.The enthalpy change of liquid-phase reaction of formation, Δ_rH~θ_m(l), is determined as (-19.091±0.015) kJ·mol^(-1) at 298.15 K by a microcalorimeter, and the enthalpy change of the solid-phase reaction of formation, Δ_rH~θ_m(s), is calculated as (139.641±0.482) kJ·mol^(-1) on the basis of a thermochemical cycle. The thermodynamic of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, Δ_cU, is determined as (-16730.21±9.25) kJ·mol^(-1) by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpies of combustion, Δ_cH~θ_m, and standard enthalpies of formation, Δ_fH~θ_m, are calculated as (-16749.42±9.25) kJ·mol^(-1) and (-2019.68±10.19) kJ·mol^(-1), respectively.
文摘The combustion energies have been determined for the solid complexes, RE(Met) 4(NO 3) 3·6H 2O(RE=La~Nd, Sm~Lu), by means of a rotating bombicalorimeter. The standard enthalpies of combustion, ΔH c,coor(s) , and standard enthalpies of formation, ΔH f,coor(s) , have been calculated for these complexes. It has been found that “tetrad effect” regularity was observed for the fact that the standard enthalpies of formation are ploted against the atomic numbers of the elements in lanthanide series. The results show that a certain amount of covalency is present for chemical bond between the rare earth cation and methionine.
基金Sponsored by Fund of Chongqing Science and Technology of China(cstc2013jcsf20001)
文摘The combustion characteristics and kinetics of anthracite,pine sawdust and their blends were investigated under combustion condition by thermogravimetric analysis,respectively.The fractions of pine sawdust in the blended samples were set to be 30%,50%,and 80%.The results showed that the ignition and burnout temperatures of pine sawdust were lower and the maximum combustion rate was higher than those of anthracite.With the increase of pine sawdust content,the ignition temperature and burnout temperature of the blends decreased,while the maximum mass loss rate and the combustible index of the blends increased;that is,the comprehensive combustion property became better.The kinetic parameters for the blends combustion under air condition were calculated based on experimental results using Coats-Redfern model.When the pine sawdust content varied in the range of 30%-80%,the combustion processes of these blends could be divided into two stages and the combustion reactions belong to the first-order reaction.The values of apparent activation energy at two individual stages decreased from 68.78to47.28kJ·mol-1 and from 113.53 to 46.43kJ·mol-1,respectively.
文摘The constant-volume combustion energy, △cU (DADE, s, 298.15 K), the thermal behavior, and kinetics and mechanism of the exothermic decomposition reaction of 1,1-diamino-2,2-dinitroethylene (DADE) have been investigated by a precise rotating bomb calorimeter, TG-DTG, DSC, rapid-scan fourier transform infrared (RSFT-IR) spectroscopy and T-jump/FTIR, respectively. The value of △cHm (DADE, s, 298.15 K) was determined as (-8518.09±4.59) j·g^-1. Its standard enthalpy of combustion, △cU (DADE, s, 298.15 K), and standard enthalpy of formation, △fHm (DADE, s, 298.15 K) were calculated to be (-1254.00±0.68) and (- 103.98±0.73) kJ·mol^-1, respectively The kinetic parameters (the apparent activation energy Ea and pre-exponential factor A) of the first exothermic decomposition reaction in a temperature-programmed mode obtained by Kissinger's method and Ozawa's method, were Ek=344.35 kJ·mol^-1, AR= 1034.50 S^-1 and Eo=335.32 kJ·mol^-1, respectively. The critical temperatures of thermal explosion of DADE were 206.98 and 207.08 ℃ by different methods. Information was obtained on its thermolysis detected by RSFT-IR and T-jump/FTIR.
基金Project supported by the Science and Technology Foundation of Shaanxi Key Laboratory of Physico-Inorganic Chemistry (No. 29-3 2001) the Science and Technology Foundation of the National Defence Key Laboratory of Propellant and Explosive Combustion of
文摘The constant-volume combustion energy, cUD(GUDN, s, 298.15 K), enthalpy of solution in acetic ether, solmHQD and kinetic behavior of the exothermic decomposition reaction of the title compound (GUDN) are deter-mined by a precise rotating bomb calorimeter, a Calvet microcalorimeter and DSC, respectively. Its standard en-thalpy of combustion, cmHQD (GUDN, s, 298.15 K), standard enthalpy of formation, fHQDm (GUDN, s, 298.15 K) and kinetic parameters of the exothermic main decomposition reaction in a temperature-programmed mode [the apparent activation energy (aE) and pre-exponential factor (A)] are calculated. The values of cUD (GUDN, s, 298.15 K), cmHQD (GUDN, s, 298.15 K), fmHQD(GUDN, s, 298.15 K) and solmHQD of GUDN are (-7068.64±2.37) J·g-1, (-1467.66±0.50) kJ·mol-1, (-319.76±0.58) kJ·mol-1 and (165.737±0.013) kJ·mol-1, respectively. The kinetic model function in integral form and the value of aEand A of the exothermic main decomposition reaction of GUDN are 220.20 kJ·mol-1 and 1021.18 s-1, respectively. The critical temperature of thermal explosion of GUDN is 217.6 ℃
基金Project supported by the National Natural Science Foundation of China (No. 20171036) Education Committee of Shaanxi Province (No. 01JK229)the National Natural Science Foundation of Shaanxi Province (No. FF02328) and National State Post Doctoral Fou
文摘The ternary solid complex has been synthesized with sodium diethyldithiocarbamate (NaEt2dtc?3H2O), 1,10-phenanthroline (o-phen?H2O) and hydrated neodymium chloride in absolute ethanol. The title complex was identified as the general formula of Nd(Et2dtc)3(phen) by chemical and elemental analyses. IR spectrum of the complex showed that the Nd3+ coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of o-phen. It was assumed that the coordination number of Nd3+ is eight.The enthalpy change of liquid-phase reaction of formation, ?rHm (l), was determined as (-12.274±0.050) kJ?mol-1 at 298.15 K by a microcalorimeter, the Θ enthalpy change of the solid-phase reaction of formation, ?rHm (s), was calculated as (149.069±0.314) kJ?mol-1 Θ on the basis of a thermochemical cycle. The thermodynamics of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, ?cU , was deter- mined as (-18674.22±8.33) kJ?mol-1 by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpy of combustion, ?cHm , and standard enthalpy of formation, ?fHm , were calculated as (-18693.43±8.33) kJ?mol-1 Θ Θ and (-47.03±9.17) kJ?mol-1, respectively.