Ferrocenium ionic liquids containing 3,4,5-tri(dodecyloxy)benzene sulfonate and bis(2-ethylhexyl)sulfosuccinate (AOT) anions

Organometallic Ionic Liquids Containing Sandwich Complexes: Molecular Design, Physical Properties, and Chemical Reactivities

Ionic liquids (ILs) are salts with low melting points and are useful as electrolytes and solvents. We have developed ILs containing cationic metal complexes, which form a family of functional liquids that exhibit unique physical properties and chemical reactivities originating from metal complexes. Our study explores the liquid chemistry in the field of coordination chemistry, where solid-state chemistry is currently the main focus. This review describes the molecular design, physical properties, and reactivities of organometallic ILs containing sandwich or half-sandwich complexes. This paper mainly covers stimuli-responsive ILs, whose magnetic properties, solvent polarities, colors, or structures change by the application of external fields, such as light, heat, and magnetic fields, or by reaction with coordinating molecules.

Ionic liquids from cationic palladium(II) chelate complexes: preparation, thermal properties, and crystal structures

Metal-containing ionic liquids comprising cationic Pd(II) chelate complexes and the bis(trifluoromethanesulfonyl)amide (Tf2N) anion were prepared: [Pd(acac)(Me4en)]Tf2N (1), [Pd(acac)(BuMe3en)]Tf2N (2), and [Pd(C8-acac)(Me4en)]Tf2N (3) (acac = 2,4-pentanedionate, C8-acac = 3-octyl-2,4-pentanedionate, Me4en = N,N,N',N'-tetramethylethylenediamine, BuMe3en = N-butyl-N,N',N'-trimethylethylenediamine). These salts were yellow solids with melting points of 85.2 °C, 71.1 °C, and 62.3 °C, respectively. During cooling from the liquid state, complex 1 exhibited crystallization, whereas 2 and 3 exhibited only glass transitions at approximately -40 °C. X-ray structure determination revealed that the cations in 1 and 3 form dimer-like arrangements and that there were no direct contacts between the charged moieties of the cations and anions in the solid state.

Laxative inspired ionic liquid lubricants with good detergency and no corrosion

1-Alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate (L-DOSS10n, n = 2, 4, 8) ionic liquids (ILs) were synthesized from dioctyl sodium sulfosuccinate (NaDOSS), which is a cheap, bulk available laxative medicine used for the treatment of constipation. The ILs showed lower corrosion levels and higher hydrolysis stabilities than conventional ILs such as 1-butyl-3-methyl imidazolium tetrafluoroborate (L-B104) and 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)imide (L-F104) due to their halogen-free characteristic. The tribological properties of the ILs were also better than those of L-B104 and L-F104 for various contacts. Thus, they can be used as replacements for conventional IL lubricants, which may solve the problems of corrosion and high cost to put conventional IL lubricants into industrial application. Coking test results indicated that the synthesized ILs have high deterging ability. Thus, these ILs may be used as lubricants that restrain carbonaceous deposition as well as oil sludge and varnish formation on the metal contacts during the sliding process. Moreover, the synthesized ILs can disperse, loosen, and remove the already formed harmful substances and keep the metal contacts clean.