The complexes 1-4 of cyclobutanocucurbit[5]uril(CyB5Q[5])with Na^(+)/K^(+)have been synthesized and characterized by single-crystal X-ray diffraction.The results show that although the inorganic salts are used when th...The complexes 1-4 of cyclobutanocucurbit[5]uril(CyB5Q[5])with Na^(+)/K^(+)have been synthesized and characterized by single-crystal X-ray diffraction.The results show that although the inorganic salts are used when the cations are the same and the anions are different,in complex 1,Na^(+)closes one port of CyB5Q[5]through Na—O seven coordination bonds to form a molecular bowl;in complex 3,Na^(+)completely closes the two ports of CyB5Q[5]to form a molecular capsule with six Na—O coordination bonds;in complexes 2 and 4,the two ports of CyB5Q[5]are completely closed to form K—O coordinated molecular capsules,but the K^(+)of complex 2 is six-coordinated and that of complex 4 is eight-/nine-coordinated.and complex 4 are connected by three oxygen bridges to form a 1D molecular chain.CCDC:2457122,1;2457121,2;2457400,3;2457120,4.展开更多
A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized...A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.展开更多
The thermal decompositions of two systems(No.1, KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ ) and No.2,KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ )) are studied using Accel...The thermal decompositions of two systems(No.1, KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ ) and No.2,KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ )) are studied using Accelerating Rate Calorimeter (ARC). Temperature vs time curve and pressure vs time curve of reactions are shown in Fig.1 and Fig.2 respectively. The basic data including reaction time(1.3 and 7.3 min respectively), initial temperature(159 and 150℃ respectively),temperature at the maximum rate(272 and 272℃ respectively), the maximum pressure(420 and 190 kPa respectively) and the activation energies(175.6 and 135.2 kJ· mol－ 1 respectively) of the thermal decomposition are given to evaluate the safety of the two systems. Results indicate that system No.2 is safer than system No.1. Compared with the traditional methods, ARC technique can be used to measure temperature and pressure of exothermic reaction concurrently, to find the tiny exothermicity and to determine the initial temperature of exothermic reaction.展开更多
The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation...The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation is da/dT = (l /P) CT '(3/2(l - a)2/3[ 1- (l - a)1/3] - 1 ). At the same time, it has been found that the apparent activation energy E increases with the increases of fraction of conversion a and the absolute temperature T, and then it shows that a linear relationship with the temperature T has been obtained.展开更多
The solubility variation of the phase system HCl-KCl-H2O at 25 ℃ is reported when θHK（interactions between two species with the same charge） and ΨHKCl（interactions among three species） are changed within ±...The solubility variation of the phase system HCl-KCl-H2O at 25 ℃ is reported when θHK（interactions between two species with the same charge） and ΨHKCl（interactions among three species） are changed within ±10%. The calculated results indicate that the interactions among the three species are much stronger than that between the two species, whereas the combination of the two kinds of interactions result in great changes of the solubility of the system. This results is important for the salting out technology of the water-salt system.展开更多
Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and ...Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.展开更多
文摘The complexes 1-4 of cyclobutanocucurbit[5]uril(CyB5Q[5])with Na^(+)/K^(+)have been synthesized and characterized by single-crystal X-ray diffraction.The results show that although the inorganic salts are used when the cations are the same and the anions are different,in complex 1,Na^(+)closes one port of CyB5Q[5]through Na—O seven coordination bonds to form a molecular bowl;in complex 3,Na^(+)completely closes the two ports of CyB5Q[5]to form a molecular capsule with six Na—O coordination bonds;in complexes 2 and 4,the two ports of CyB5Q[5]are completely closed to form K—O coordinated molecular capsules,but the K^(+)of complex 2 is six-coordinated and that of complex 4 is eight-/nine-coordinated.and complex 4 are connected by three oxygen bridges to form a 1D molecular chain.CCDC:2457122,1;2457121,2;2457400,3;2457120,4.
文摘A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.
文摘The thermal decompositions of two systems(No.1, KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ ) and No.2,KClO3(52.2％ )/CuO(26.0％ )/S(9.6％ )/Mg- Al(3.5％ )/C6Cl6(4.35％ )) are studied using Accelerating Rate Calorimeter (ARC). Temperature vs time curve and pressure vs time curve of reactions are shown in Fig.1 and Fig.2 respectively. The basic data including reaction time(1.3 and 7.3 min respectively), initial temperature(159 and 150℃ respectively),temperature at the maximum rate(272 and 272℃ respectively), the maximum pressure(420 and 190 kPa respectively) and the activation energies(175.6 and 135.2 kJ· mol－ 1 respectively) of the thermal decomposition are given to evaluate the safety of the two systems. Results indicate that system No.2 is safer than system No.1. Compared with the traditional methods, ARC technique can be used to measure temperature and pressure of exothermic reaction concurrently, to find the tiny exothermicity and to determine the initial temperature of exothermic reaction.
文摘The thermal decomposition process of KAI(SO4)2’ 12H2O and its kinetics has been studied by TG-DTG. By Dollimore method, D3 is defined as the second step of thermal decomposition kinetic model and its kinetic equation is da/dT = (l /P) CT '(3/2(l - a)2/3[ 1- (l - a)1/3] - 1 ). At the same time, it has been found that the apparent activation energy E increases with the increases of fraction of conversion a and the absolute temperature T, and then it shows that a linear relationship with the temperature T has been obtained.
文摘The solubility variation of the phase system HCl-KCl-H2O at 25 ℃ is reported when θHK（interactions between two species with the same charge） and ΨHKCl（interactions among three species） are changed within ±10%. The calculated results indicate that the interactions among the three species are much stronger than that between the two species, whereas the combination of the two kinds of interactions result in great changes of the solubility of the system. This results is important for the salting out technology of the water-salt system.
文摘Two new substituted calix[4]arene derivatives 2 and 3 were synthesized by the reaction of calix[4]arene with methyl o-bromomethyl-benzoate in the presence of potassium carbonate under nitrogen. Their compositions and structures were confirmed by elemental analysis, IR, 1H NMR and 13C NMR. Both the compounds are in the cone conformation. The percent extraction of the tetrasubstituted calix[4]arene derivative 2 for Li +, Na +, K + and Cs + are 6.8, 19.4, 69.8 and 7.1, respectively, indicating that derivative 2 extracts K + better than Li +, Na + and Cs +. The higher selective complexation of compound 2 with K + elucidated that the radius of potassium cation may be matched with the inclusion cavity formed by the carbonyl and phenoxy groups. There is only a little extractivity of disubstituted calix[4]arene derivative 3 for alkali metal ions.
