Ionic Liquid-Crystal Precursors (ILCPs) for CuCl Platelets:  The Origin of the Exothermic Peak in the DSC Curves

Abstract

We have recently reported (Taubert, A.; Steiner, P.; Mantion, A. J. Phys. Chem. B 2005, 109, 15542) that DSC traces of an ionic liquid-crystal precursor for CuCl nanoplatelets exhibit an intense exothermic peak. The current paper presents a detailed investigation into the origin of this exothermic peak. Electron paramagnetic resonance spectroscopy, high-temperature X-ray scattering, and isothermal differential scanning calorimetry show that the Cu(II)−Cu(I) reduction is complete after about 35 min. It is the rate-determining step in the CuCl formation process and is responsible for the exothermic peak. Cu(II) reduction strongly overlaps with the formation of a first generation of CuCl particles. The formation of the large CuCl platelets observed in the SEM (Taubert, A. Angew. Chem., Int. Ed., 2004, 43, 5380) is inhibited by the organic matrix and occurs over the course of about 5 h.

Tetrahalidocuprates(ii)—structure and EPR spectroscopy. Part 1: Tetrabromidocuprates(ii)

“…Moreover, alkylpyridinium tetrahalidocuprate ILs and ionic liquid crystals (ILCs) have also been used as precursors for inorganic materials. [34][35][36] Reports on tetrahalidometalate-based ILCs and their transformation into inorganic materials are, however, relatively rare. [30][31][32][33][37][38][39][40][41][42][43][44][45][46][47] This is somewhat surprising because metal containing ILs and ILCs may open the door towards a new valuable branch of IL research, which derives its importance from the additional properties such as colour, geometry, or magnetism, which are brought about the material by the metal ion.…”

Anion metathesis in ionic silicananoparticle networks

“…[1][2][3][4][5][6][7][8][9][10][11][12] Such materials are very promising for many different applications, like among others, catalysis, 13-15 luminescence [16][17][18] or as electrolytes. [1][2][3][4][5][6][7][8][9][10][11][12] Such materials are very promising for many different applications, like among others, catalysis, 13-15 luminescence [16][17][18] or as electrolytes.…”

Inorganic Nanomaterials Synthesis Using Ionic Liquids

“…At elevated temperatures, a redox reaction between the ascorbic acid head group and the Cu(II) ions in the center of the bis(dodecylpyridinium) tetrachlorocuprate leads to the formation of Cu(I) ions, which then rapidly react with one of the surrounding chloride ions to form CuCl. 30 The details of this reaction have been studied in detail. 30,31,55, 143 These studies are the first to demonstrate that ILs can not only be used as solvents or templates but also as reactants, which at the same time are solvents and templates for the growth of inorganic nanomaterials.…”

“…21,22,[29][30][31][32][33][34][35][36] While the first studies simply used an IL or a mixture of an IL with a conventional solvent as a reaction medium-sometimes with interesting and useful results 19,21,22,24-28,37-54 -these studies did not provide broader strategies for materials synthesis.…”