The interplay between molecular structure and dielectric propertiesin ionic liquids: A comparative study

Rationalizing energy level alignment by characterizing Lewis acid/base and ionic interactions at printable semiconductor/ionic liquid interfaces

“…6,7 The extent of this ordering, as a function of IL coverage from single-to-multiple monolayers, is very much controlled by the strength of substrate interactions in the first layer, including length of the alkyl tails in the imidazolium cation, the size and charge density of the anion, the type of structures formed at the interface, and the extrapolation of those structures to the bulk. [6][7][8][9]14,15 Fig. 2A shows the molecular structures of the EMIM + and TFSI À (including numeric labelling of the carbon atoms) and Fig.…”

“…Such a result is consistent with recent electrochemical/STM and molecular dynamics modelling studies, which suggest that the initial EMIM + /TFSI À monolayer is well ordered over short length scales but that more than one orientation of the anion and cation are possible. 6,7,9,10,14,15 An important caveat is that our surface is template-stripped gold, which has been reported to undergo surface reconstructions due to monolayer adsorption and/or aging [44][45][46] and is not a true single crystal.…”

“…For context, we compare and contrast the energetics and structural order at IL/semiconductor interfaces with previous reports of Au (111) surfaces and structural organization of ILs at nanometer length scales. 6,7,10,14,15 The observed organization of IL cations and anions is very much reminiscent of a subset of electrical double layers associated with compact electrode/electrolyte interfaces termed ''Stern layers'', which exhibit significant long-range order arising from strong intermolecular and surface interactions and can create electrostatic potential drops exceeding 10 8 V cm À1 . 3,4,16,17 Yet the gold surface lacks Lewis acid and base sites commonly associated with semiconductor mid-gap states, and by comparison, interactions are relatively weak and confined to within the first 1-2 ML.…”

Synthesis, vibrational and thermal properties of new functionalized 1- (2-hydroxyethyl) -3-methylimidazolium dihydrogenophosphate ionic liquid

“…The peak at 117°C that corresponds probably to the melting point of a second morphology of the same sample [50][51]. The temperatures of decomposition and total decomposition are indicated in Table 3.…”