Building Blocks for Ionic Liquids: Vapor Pressures and Vaporization Enthalpies of Alkoxy Derivatives of Imidazole and Benzimidazole

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• 作者：Inna V. Garist ; Sergey P. Verevkin ; Artemiy A. Samarov ; Jason E. Bara ; Michelle S. Hindman ; Scott P. O. Danielsen
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：November 28, 2012
• 年：2012
• 卷：51
• 期：47
• 页码：15517-15524
• 全文大小：298K
• 年卷期：v.51,no.47(November 28, 2012)
• ISSN：1520-5045

文摘

The design of physical solvents for applications such as CO₂ capture has been an important research area as great emphasis is being placed on reducing greenhouse gas emissions. In gas treating with physical solvents, one of the most important solvent properties needed for efficient process operation is a low vapor pressure (100 Pa) at ambient temperature. We have identified alkoxy-functionalized imidazoles and benzimidazoles as candidates that can meet this criterion. Vapor pressures of alkoxy derivates of imidazole and benzimidazole have been determined as a function of temperature by the transpiration method. From these data, the molar enthalpies of vaporization (螖_l^gH_m) were calculated. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of the parent species鈥攄imethyl ethers of ethylene glycol, diethylene glycol, and triethylene glycol. We observe that for species with the same number of atoms in the side chain [e.g., 1-butylimidazole and 1-(2-methoxyethyl)-imidazole], replacing every third methylene group with an ether oxygen reduces vapor pressure by 50鈥?5%.