The IR spectrum and 11B and 27Al MAS NMR spectra of Al18B4O33 are presented and discussed in relation to the possible existence of boron atoms substituting for aluminum atoms. The IR spectrum shows that the strong vi...The IR spectrum and 11B and 27Al MAS NMR spectra of Al18B4O33 are presented and discussed in relation to the possible existence of boron atoms substituting for aluminum atoms. The IR spectrum shows that the strong vibrations of the BO3 groups are present in the 1 500-1 200 cm-1 region, and very weak bands of BO4 units are present in the region from 1 000 to 1 100 cm-1. 11B MAS NMR spectrum indicates that the strong signal for BO3 units appears in the region from δ+5 to δ+20, and the very weak signal for BO4 units is at about δ- 1, while 27Al MAS NMR spectrum shows five peaks at about δ+62, +42. 1, +14, -4. 7 and -6. 4, originating from AlO4, AlO4, AlO5, AlO6 and AlO6, respectively. These results reveal that there are minor BO4 units in Al18B4O33, indicating that a small amount of B atoms substitute for Al atoms in the 4-fold coordination.展开更多
An acid molten salt was formed by means of mixing 1 -methyl- 3 -ethylimidazolium chloride with AlCl3 and LiAlCl4 at ambient temperature. The solubility of LiAlCl4 in the acid molten salt was measured. Variations of sp...An acid molten salt was formed by means of mixing 1 -methyl- 3 -ethylimidazolium chloride with AlCl3 and LiAlCl4 at ambient temperature. The solubility of LiAlCl4 in the acid molten salt was measured. Variations of specific conductivity, density and kinetic viscosity of molten salt with mole ratio o f MeEtlmCl/A1lCl3/LiAlCl4 were observed. A solubility maximum of LiAlCl4 with 5 4% in molar fraction was shown at a mole ratio of AlCl43/MeEtlmCl = 1 .2. An increase in density and viscosity, and a decrease in specific conductivity were found with increasing the concentrations of LiAlCl4 and AlCl3. The dependence of specific conductivity of this acid molten salt upon temperature was found to display Vogel-Tammanm-Fucher behavior. However, Arrhenius behavior was observed at two special mole ratios of MeEtImCl/AlCl3/LiAlCl4 = 1:1.5:0.05 and 1. 1.5:0. 10. The conductivity equations of this molten salt at various compositions were constructed. The ion interaction in the acid molten salt was studied using 7Li and 27Al nuclear magnetic resonance spectroscopic methods. The effect of concentrations of LiAlCl4 and AlCl3 on the ion interaction was also discussed.展开更多
基金Supported by the National Natural Science Foundation of China.
文摘The IR spectrum and 11B and 27Al MAS NMR spectra of Al18B4O33 are presented and discussed in relation to the possible existence of boron atoms substituting for aluminum atoms. The IR spectrum shows that the strong vibrations of the BO3 groups are present in the 1 500-1 200 cm-1 region, and very weak bands of BO4 units are present in the region from 1 000 to 1 100 cm-1. 11B MAS NMR spectrum indicates that the strong signal for BO3 units appears in the region from δ+5 to δ+20, and the very weak signal for BO4 units is at about δ- 1, while 27Al MAS NMR spectrum shows five peaks at about δ+62, +42. 1, +14, -4. 7 and -6. 4, originating from AlO4, AlO4, AlO5, AlO6 and AlO6, respectively. These results reveal that there are minor BO4 units in Al18B4O33, indicating that a small amount of B atoms substitute for Al atoms in the 4-fold coordination.
文摘An acid molten salt was formed by means of mixing 1 -methyl- 3 -ethylimidazolium chloride with AlCl3 and LiAlCl4 at ambient temperature. The solubility of LiAlCl4 in the acid molten salt was measured. Variations of specific conductivity, density and kinetic viscosity of molten salt with mole ratio o f MeEtlmCl/A1lCl3/LiAlCl4 were observed. A solubility maximum of LiAlCl4 with 5 4% in molar fraction was shown at a mole ratio of AlCl43/MeEtlmCl = 1 .2. An increase in density and viscosity, and a decrease in specific conductivity were found with increasing the concentrations of LiAlCl4 and AlCl3. The dependence of specific conductivity of this acid molten salt upon temperature was found to display Vogel-Tammanm-Fucher behavior. However, Arrhenius behavior was observed at two special mole ratios of MeEtImCl/AlCl3/LiAlCl4 = 1:1.5:0.05 and 1. 1.5:0. 10. The conductivity equations of this molten salt at various compositions were constructed. The ion interaction in the acid molten salt was studied using 7Li and 27Al nuclear magnetic resonance spectroscopic methods. The effect of concentrations of LiAlCl4 and AlCl3 on the ion interaction was also discussed.
