McCune Jade A, He Peizhao, Petkovic Marina, Coleman Fergal, Estager Julien, Holbrey John D, Seddon Kenneth R, Swadźba-Kwaśny Małgorzata
QUILL, The Queen's University of Belfast, Belfast, BT9 5AG, UK.
Phys Chem Chem Phys. 2014 Nov 14;16(42):23233-43. doi: 10.1039/c4cp03217a.
Gutmann Acceptor Number (AN) values have been determined for Brønsted acid-ionic liquid mixtures, over a wide compositional range. Four systems of general formula [C2mim][A]-HA (A(-) = bistriflamide, NTf2; triflate, OTf; mesylate, OMs; or acetate, OAc, C2mim = 1-ethyl-3-methylimidazolium cation) were studied. A library of Brønsted acidic systems of varying acidity was constructed and the AN parameter was found to be a convenient approach for quantifying their acidity. HOAc, HOMs and HOTf, when dissolved in ionic liquids, were found to associate with the respective anions to form hydrogen-bonded anionic clusters, A(HA)x. In contrast, HNTf2 was solubilised as a discrete, undissociated molecule. AN values were sensitive to the presence of anionic clusters; acidity could be buffered to a particular AN by binding the solubilised acid in the anionic cluster form. Overall, a simple way to manipulate and quantify the Brønsted acidity of acid-ionic liquid mixtures was demonstrated, and measured AN values were related to liquid speciation.
已在很宽的组成范围内测定了布朗斯特德酸 - 离子液体混合物的古特曼受体数（AN）值。研究了通式为[C2mim][A] - HA的四个体系（A(-) = 双三氟甲磺酰亚胺盐，NTf2；三氟甲磺酸盐，OTf；甲磺酸盐，OMs；或乙酸盐，OAc，C2mim = 1 - 乙基 - 3 - 甲基咪唑鎓阳离子）。构建了一系列酸度不同的布朗斯特德酸性体系，发现AN参数是量化其酸度的便捷方法。发现HOAc、HOMs和HOTf溶解在离子液体中时会与各自的阴离子缔合形成氢键合的阴离子簇A(HA)x。相比之下，HNTf2以离散的、未离解的分子形式溶解。AN值对阴离子簇的存在敏感；通过将溶解的酸以阴离子簇形式结合，可以将酸度缓冲到特定的AN值。总体而言，展示了一种操纵和量化酸 - 离子液体混合物布朗斯特德酸度的简单方法，并且所测得的AN值与液体形态相关。
