New ionic liquids and ionic liquid crystalline materials with custom-tailored properties were synthesized based on long-alkyl-chain-derivatized 1,3-dialkylimidazolium salts.

Owing to shifting market demands, it is important to convert ethylene to propylene. One attractive way to achieve this conversion is the dimerization of ethylene to 1‐butene, followed by isomerization to 2‐butene and subsequent metathesis of 2‐butene/ethylene olefin. Our contribution focuses on combining the first two steps. Herein, we report a highly selective tandem dimerization/isomerization of ethylene to 2‐butene catalyzed by homogeneously dissolved cationic nickel complexes. These catalysts can be efficiently immobilized by using the supported ionic liquid phase technology. Such supported ionic liquid phase materials have been tested under continuous gas phase conditions and demonstrated attractive catalytic performance with respect to both catalyst stability and productivity after the optimization of support, ionic liquid, ligand, and process parameters. The limited thermal stability of the nickel complexes and olefin condensation at too low temperatures require a careful thermal management of the fixed‐bed reactor.

Two glucose-derived thiourea derivatives, 2a and 2b, were prepared by addition of the corresponding amino sugars to a solution of 4-nitrobenzoyl isothiocyanate (Scheme 1). The thioureas were isolated as colorless solids in good yields and were fully characterized by NMR spectroscopy, optical rotation, elemental analysis, and also by single-crystal X-ray diffraction. Attempts to obtain Cu^II and Ni^II bis(chelate) complexes with these thioureas failed. However, the C(1)-protected thiourea derivative 2a reacted with orthopalladated acetato-bridged dimers to afford the corresponding monomeric Pd^II complexes 3 and 4 (Scheme 2). In these compounds, the thiourea coordinates to the metal as monoanionic O,S chelate ligand, which was confirmed by X-ray crystallography

The cage-phosphine 2-thia-1,3,5-triaza-7-phosphaadamantane-2,2-dioxide (PASO2) was reacted with various transition metal precursors to give the complexes cis-[Mo(CO)4(PASO2)2], [AuCl(PASO2)], cis-[PtCl2(PASO2)2], [Ru(η6-p-cym)Cl2(PASO2)], [Rh(η5-C5Me5)Cl2(PASO2)], and [Rh(η5-C5Me5)Cl(PASO2)2]+ as well as the cyclometalated palladium(II) complexes [PdCl{κC,N-C6H4C(Ph)NCH2CO2Et}(PASO2)] and [PdCl(κC,N-1,8-C10H6NMe2)(PASO2)]. The compounds were characterized by spectroscopic methods and several examples by single-crystal X-ray diffraction. The stereoelectronic properties of PASO2 were determined by computational methods and were compared with those of other phosphines, in particular 1,3,5-triaza-7-phosphaadamantane.

(PPh 3 OdiMePh = (2-(2,6-dimethylphenoxy)phenyl)diphenylphosphine) 3 were immobilized as Supported Ionic Liquid Phase (SILP) catalysts and applied for the tandem dimerization/isomerization of ethylene to 2-butene in a fluidized bed reactor. The better heat removal in the fluidized bed improves the catalyst stability and allows for a more detailed investigation of the deactivation mechanism. Based on kinetic studies, a second order deactivation mechanism is proposed, in which two nickel complexes dimerize if the supply of ethene is insufficient.

In the current work, novel symmetrically alkyl-substituted imidazolium-based ionic liquids have been synthesized featuring either iodide (I) or selenocyanate (SeCN) as counteranions. Physicochemical assays based on spectroscopy and electrochemistry techniques have been performed to identify the best ionic liquid for application as electrolytes in quasi-solid-state dye-sensitized solar cells (qssDSSC). The latter were mixed with additives such as 4-tert-butylpyridine (4tbpy) and guanidinium thiocyanate (GuSCN) to optimize electrode surface coverage, ionic diffusion, and dye regeneration. In addition, we demonstrate that electrolytes containing a mixture of I and (SeCN) enhance the open-circuit voltage of the final quasi-solid-state device by up to 70 mV. As such, iodine-pseudohalogen electrolytes reveal in qssDSSCs a good balance between dye regeneration and hole transport and, in turn, enhance the overall solar energy conversion efficiency by 70% with respect to reference qssDSSCs with iodine-based electrolytes. Finally, devices with the iodine-pseudohalogen electrolyte show a 1000 h stable efficiency of 7-8% under outdoor temperature operation conditions and 1 sun illumination.

Today's catalytic forecast: migrating front and hot spots The cover picture shows the conversion of ethylene to 1-butene and 2-butene by using a fixed-bed reactor with the catalyst bed consisting of supported ionic liquid phase (SILP) catalyst particles. In their Full Paper on p. 162 ff., P. Wasserscheid et al. describe that the applied homogeneous nickel complex exhibits a high activity and selectivity to 2-butene. The observed catalyst deactivation is attributed to a migrating reaction/deactivation front travelling through the catalyst bed in combination with hot spot formation. The time until catalyst deactivation could be heavily prolonged by optimization of catalytic and process parameters.

Adding to the versatile class of ionic liquids (ILs), an entirely new series of imidazolinium-based ionic liquids is reported herein, offering chirality and important thermal characteristics, such as polymorphism, glass transition, and plastic crystalline behavior. An efficient and general procedure for the preparation of long N,N′-alkyl chain-substituted compounds with either saturated (s) or chiral (c) cyclohexyl (cyC6)-substituted imidazolium (Im) backbones, namely, [C12C12RsIm]­[A] (A = Br–, [BF4]−, [ClO4]−, [PF6]−; R = H, Me, i Pr) and [C12C12cIm-cyC6]­[A] (A = Br–, I–, [I3]−, [BF4]−, [ClO4]−, [PF6]−, [SbF6]−, [BPh4]−), was developed, and the novel compounds were studied by thermochemical methods (DSC, TGA), X-ray diffraction in the small angle regime (SAXS), single-crystal X-ray diffraction (SC-XRD), and specific rotation analysis.