作者:Francesca D'Anna、H. Q. Nimal Gunaratne、Giuseppe Lazzara、Renato Noto、Carla Rizzo、Kenneth R. Seddon
DOI:10.1039/c3ob40807h
日期:——
A new class of functionalised dicationic ionic liquids, containing a central cationic unit capped by a basic functionality (imidazole), has been synthesised. These salts have been characterised in isotropic solution using proton and 2D-NMR spectroscopy, and their thermal stability has been studied by DSC and TGA. All these novel salts contain the 1-(1-imidazolylmethyl)-3,5-di1-(3′-octylimidazolylmethyl)}-benzene cation as a defining structural motif. Salts of both singly and doubly charged anions were prepared and, in particular, the selected monoanions (Br−, [BF4]−, or [NTf2]−) differ in size, shape and hydrogen-bonding ability, whereas the dianions differ in the nature of the spacer, such as 1,4-benzenedicarboxylate, 2,6-naphthalenedicarboxylate, 1,5- and 2,6-naphthalenedisulfonate, 1,4-butanedicarboxylate, and 1,6-hexanedicarboxylate. These ionic liquids exhibit the presence of different conformers in solution, whose distribution is affected by the nature of the anion. The nature of the anion also affects their thermal stability.
一种新型功能化二阳离子离子液体的类被合成,该类离子液体含有一个中央阳离子单元,并以基础功能基团(咪唑)作为封端。通过质子和二维核磁共振(NMR)光谱分析,这些盐在各向同性溶液中得到了表征,同时还通过差示扫描量热法(DSC)和热重分析(TGA)研究了它们的热稳定性。所有这些新型盐均包含1-(1-咪唑甲基)-3,5-二1-(3′-辛基咪唑甲基)}-苯阳离子作为其特征的结构基元。制备了单负和双负离子的盐,特别是所选的单负离子(Br−、[BF4]−或[NTf2]−)在大小、形状和氢键能力上存在差异,而双负离子则在间隔基的性质上存在差异,例如1,4-苯二甲酸盐、2,6-萘二甲酸盐、1,5-和2,6-萘二磺酸盐、1,4-丁二酸盐和1,6-己二酸盐。这些离子液体在溶液中表现出不同构象的存在,其分布受到阴离子性质的影响。阴离子的性质还影响它们的热稳定性。