To date, few reports have been concerned with the physical properties of the liquid phases of imidazoles and benzimidazoles- potential starting materials for a great number of ionic liquids. Prior research has indicat...To date, few reports have been concerned with the physical properties of the liquid phases of imidazoles and benzimidazoles- potential starting materials for a great number of ionic liquids. Prior research has indicated that alkylimidazole solvents exhibit different, and potentially advantageous physical properties, when compared to corresponding imidazolium-based ionic liquids. Given that even the most fundamental physical properties of alkylimidazole solvents have only recently been reported, there is still a lack of data for other relevant imidazole derivatives, including benzimidazoles. In this work, we have synthesized a se- ries of eight 1-n-alkylbenzimidazoles, with chain lengths ranging from ethyl to dodecyl, all of which exist as neat liquids at ambient temperature. Their densities and viscosities have been determined as functions of both temperature and molecular weight. Alkylbenzimidazoles have been found to exhibit viscosities that are more similar to imidazolium-based ILs than al- kylimidazoles, owed to a large contribution to viscosity from the presence of a fused ring system. Solubilities of CO2 and SO2, two species of concern in the emission of coal-fired power generation, were determined for selected alkylbenzimidazoles to understand what effects a fused ring system might have on gas solubility. For both gases, alkylbenzimidazoles were deter- mined to experience physical, non-chemically reactive, interactions. The solubility of CO2 in alkylbenzimidazoles is 10%-30% less than observed for corresponding ILs and alkylimidazoles. 1-butylbenzimidazole was found to readily absorb at least 0.333 gram SO2 per gram at low pressure and ambient temperature, which could be readily desorbed under an N： flush, a behavior more similar to imidazolium-based ILs than alkylimidazoles. Thus, we find that as solvents for gas separations, benzimidazoles share characteristics with both ILs and alkylimidazoles.展开更多
设计合成了以高价态环状三亚氨基磷腈为阴离子、烷基咪唑为阳离子的1-乙基-3-甲基咪唑三亚氨基磷腈等五种新型离子液体。运用FT IR、1 H NMR和31P NMR确定了它们的组成和结构,并进行了相转变温度、热稳定性、电导率和溶解性的测试。结...设计合成了以高价态环状三亚氨基磷腈为阴离子、烷基咪唑为阳离子的1-乙基-3-甲基咪唑三亚氨基磷腈等五种新型离子液体。运用FT IR、1 H NMR和31P NMR确定了它们的组成和结构,并进行了相转变温度、热稳定性、电导率和溶解性的测试。结果显示,这类高价态的离子液体在室温下呈液态,分解温度为210℃,电导率的变化范围是0.002~10.4mS/cm。这类离子液体是目前文献报道的相转变温度最低的高价离子液体。展开更多
基金supported by ION Engineering, LLCUnited States Department of Energy-National Energy Technology Laboratory(DE-FE00005799)the National Science Foundation Research Experiences for Undergraduates Program (EEC-1062705)
文摘To date, few reports have been concerned with the physical properties of the liquid phases of imidazoles and benzimidazoles- potential starting materials for a great number of ionic liquids. Prior research has indicated that alkylimidazole solvents exhibit different, and potentially advantageous physical properties, when compared to corresponding imidazolium-based ionic liquids. Given that even the most fundamental physical properties of alkylimidazole solvents have only recently been reported, there is still a lack of data for other relevant imidazole derivatives, including benzimidazoles. In this work, we have synthesized a se- ries of eight 1-n-alkylbenzimidazoles, with chain lengths ranging from ethyl to dodecyl, all of which exist as neat liquids at ambient temperature. Their densities and viscosities have been determined as functions of both temperature and molecular weight. Alkylbenzimidazoles have been found to exhibit viscosities that are more similar to imidazolium-based ILs than al- kylimidazoles, owed to a large contribution to viscosity from the presence of a fused ring system. Solubilities of CO2 and SO2, two species of concern in the emission of coal-fired power generation, were determined for selected alkylbenzimidazoles to understand what effects a fused ring system might have on gas solubility. For both gases, alkylbenzimidazoles were deter- mined to experience physical, non-chemically reactive, interactions. The solubility of CO2 in alkylbenzimidazoles is 10%-30% less than observed for corresponding ILs and alkylimidazoles. 1-butylbenzimidazole was found to readily absorb at least 0.333 gram SO2 per gram at low pressure and ambient temperature, which could be readily desorbed under an N： flush, a behavior more similar to imidazolium-based ILs than alkylimidazoles. Thus, we find that as solvents for gas separations, benzimidazoles share characteristics with both ILs and alkylimidazoles.
文摘设计合成了以高价态环状三亚氨基磷腈为阴离子、烷基咪唑为阳离子的1-乙基-3-甲基咪唑三亚氨基磷腈等五种新型离子液体。运用FT IR、1 H NMR和31P NMR确定了它们的组成和结构,并进行了相转变温度、热稳定性、电导率和溶解性的测试。结果显示,这类高价态的离子液体在室温下呈液态,分解温度为210℃,电导率的变化范围是0.002~10.4mS/cm。这类离子液体是目前文献报道的相转变温度最低的高价离子液体。
