A New Class of Task‐Specific Imidazolium Salts and Ionic Liquids and Their Corresponding Transition‐Metal Complexes for Immobilization on Electrochemically Active Surfaces

Abstract

Adding to the versatile class of ionic liquids, we report the detailed structure and property analysis of a new class of asymmetrically substituted imidazolium salts, offering interesting thermal characteristics, such as liquid crystalline behavior, polymorphism or glass transitions. A scalable general synthetic procedure for N-polyaryl-N'-alkyl-functionalized imidazolium salts with para-substituted linker (L) moieties at the aryl chain, namely [LPh m Im H R] + (L = Br, CN, SMe, CO 2 Et, OH; m = 2, 3; R = C 12 , PEG n ; n = 2, 3, 4), was developed. These imidazolium salts were studied by single-crystal X-ray diffraction (SC-XRD), NMR spectroscopy and thermochemical methods (DSC, TGA). Furthermore, these imidazolium salts were used as N-heterocyclic carbene (NHC) ligand precursors for mononuclear, first-row transition metal complexes (Mn

Synthesis and Physical Properties of Tunable Aryl Alkyl Ionic Liquids (TAAILs) Comprising Imidazolium Cations Blocked with Methyl‐, Propyl‐ and Phenyl‐Groups at the C2 Position

“…Ionic liquids (ILs) stand out from conventional solvents due to their interesting and unusual physical properties, and are already present in many areas of chemistry, especially in synthesis, catalysis, biochemistry and material science. [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ] Since they can be specifically customized to their fields of application due to the numerous possibilities to modify their structure, they are also referred to as green solvents or designer solvents in industry and academia. [ 9 , 10 ] Ionic liquids are defined as salts with a melting point below 100 °C and consist of organic cations, such as the commonly used 1‐butyl‐3‐methylimidazolium (BMIM), and organic as well as inorganic anions, for example [Br] − or bis(trifluoromethylsulfonyl)imide [NTf 2 ] − .…”