Small-angle neutron scattering from mixtures of long- and short-chain 3-alkyl-1-methyl imidazolium bistriflimides
Citations Over Time
Abstract
The preparation of mixtures of ionic liquids (ILs) represents an attractive strategy to tune their properties, an important aspect of which is to understand how the structure of the bulk varies with composition. In this study, small-angle neutron scattering (SANS) was used to probe mixtures of methylimidazolium-based ionic liquids [Cnmim][Tf2N] with [C2mim][Tf2N]) (n = 4, 6, 8 and 10) and of [Cmmim][Tf2N] with [C12mim][Tf2N] (m = 2, 4, 6 and 8). Mixtures were prepared in both contrasts, which is to say that one component would be fully hydrogenated while the other was fully deuterated, and vice versa. Data were fitted using a range of appropriate models, of which the Teubner-Strey model provided most useful information and the pure materials showed a nascent Polar Non-polar Peak (PNPP) for n = 6, which became more evident as n increased. In the mixtures [Cnmim]x[C2mim]1-x[Tf2N], the PNPP was evident for n = 10 and 8, nascent for n = 6 and absent for n = 4, with percolation showing a very strong dependence on the chain length of the added IL, [Cnmim][Tf2N]. In contrast, while the ability of [C12mim][Tf2N] to form percolated structures was damped when mixed with [Cmmim][Tf2N], as m increased from 2 to 6, this effect was less strong. However, data obtained for mixtures of [C12mim][Tf2N] and [C8mim][Tf2N], both of which percolate as pure materials, did not fit easily in any of the models applied to the previous systems and gave results that depended on the contrast used. Complementary small-angle X-ray scattering (SAXS) data, however, showed the expected evolution and behaviour of the PNPP, COP and CP, revealing that the unexpected observations were due to an adventitious matching out of isotopic contrasts. As well as revealing details of the structures of these IL mixtures, the results also point to complementary strategies for generating bulk percolated structures as a function of cation chain length.
Related Papers
- → ChemInform Abstract: One‐Pot Green Synthesis of Azides from Alcohols Using Broensted Acidic Ionic Liquid [HMIM][BF4] as Solvent and Catalyst.(2014)1 cited
- → ChemInform Abstract: Formation of 2H‐Benzimidazole 1,3‐Dioxides by Reaction of Benzofuroxans with Alcohols and Alkyl Halides in the Presence of Acids.(1995)
- → ChemInform Abstract: Novel Synthesis of Selenones: Application to the Synthesis of Alkyl Cyclopropanecarboxylates.(1988)
- → ChemInform Abstract: Distinguishing Between Polar and Electron‐Transfer Mechanisms for Reactions of Anions with Alkyl Halides.(1987)
- → ChemInform Abstract: DIORGANOSTANNYLENES. II. PHOTOLYTIC REACTION OF DIPHENYLTIN WITH ALKYL HALIDES(1977)