Is there anything resembling a truly noncoordinating anion? Would it not be great to able prepare any crazy, beautiful, or simply useful cationic species that one has in mind, detected by mass spectroscopy? In condensed phases the target cation partnered with suitable counteranion. This is moment when difficulties arise and many wonderful ideas end sink owing coordination decomposition of anion. However, maybe these counteranion problems can overcome new weakly coordinating anions (WCAs)....

We have developed a simple and quantitative explanation for the relatively low melting temperatures of ionic liquids (ILs). The basic concept was to assess Gibbs free energy fusion (ΔfusG) process IL(s) → IL(l), which relates point IL. This done using suitable Born−Fajans−Haber cycle that closed by lattice (i.e., IL(g)) solvation IL(g) IL(l)) energies constituent ions in molten salt. As part this project we synthesized determined accurate points (by DSC) dielectric constants spectroscopy) 14...

Purified LiAlH4 reacts with fluorinated alcohols HORF to give LiAl(ORF)4 (RF=-CH(CF3)2, 2a; -C(CH3)(CF3)2, 2b; -C(CF3)3, 2c) in 77 90% yield. The crude lithium aluminates react metathetically AgF the silver AgAl(ORF)4 3a; 3b; 3c) almost quantitative solid-state structures of solvated 3a-c showed that cation is only weakly coordinated (CN(Ag)=6-10; CN = coordination number) by solvent and/or weak - anion contacts Ag-X (X=O, F, Cl, C). strength was analysed Brown's bond-valence method and then...

Abstract Gibt es so etwas wie ein wirklich nichtkoordinierendes Anion? Wäre nicht großartig, jede verrückte, schöne oder einfach nur nützliche kationische Spezies herstellen zu können, sei es, weil sie einen gerade interessiert man vielleicht schon einmal im Massenspektrum entdeckt hat? Um dieses Ziel in kondensierter Phase erreichen, müssen die Zielkationen mit einem geeigneten Gegenion versehen werden – dies ist der Moment, bei dem häufig Schwierigkeiten auftreten und viele gute Ideen...

Risky business? The use of dative bonds to describe the electronic structure main-group compounds has come into vogue in recent years. But where are limits? When does description as a bond make sense and when is this view misleading? This Essay develops idea on basis current examples.

The possibility of obtaining frustrated Lewis pairs (FLPs) suitable for H2-activation based on the acid B(Ohfip)3 1 (Ohfip = OC(H)(CF3)2) was investigated. In this context, crystal structure as well very weak adduct 1·NCMe determined. When reacting solutions with H2 (1 bar) and selected phosphanes, amines, pyridines N-heterocyclic carbenes, dihydrogen activation never observed. Without H2, formation observed to be an equilibrium process, regardless base adduct. Thus, thermodynamics in...

An aluminium battery using an organic redox polymer as a positive electrode material delivers high reversible specific capacities at fast C-rates.

Abstract This recommendation proposes a definition for the term “pnictogen bond”; pnictogen bond designates subset of attractive interactions between an electrophilic region on atom in molecular entity and nucleophilic another, or same, entity.

We have used microwave dielectric relaxation spectroscopy to study the picosecond dynamics of five low-viscosity, highly conductive room temperature ionic liquids based on 1-alkyl-3-methylimidazolium cations paired with bis((trifluoromethyl)sulfonyl)imide anion. Up 20 GHz response is bimodal. The longest component at time scale several 100 ps reveals strongly nonexponential and correlates viscosity in a manner consistent hydrodynamic predictions for diffusive reorientation dipolar ions....

The molecular volume Vm (that is, the sum of ionic volumes Vion constituent ions) an liquid (IL) in combination with anion-dependent empirical relationship is all one needs to predict physical properties such as viscosity, conductivity, and density [N(CN)2]−, [BF4]−, [PF6]−, [N(SO2CF3)2]− liquids, including those which may yet only exist on paper. Supporting information for this article available WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z700941_s.pdf or from author. Please...

Lewis superacidity? In analogy to Brønsted superacids, superacids can be defined as acids that are stronger than the strongest conventional and commercially employed acid SbF5. The fluorobenzene complex PhF→Al(ORF)3 (RF=C(CF3)3) qualifies an easily accessible, non-oxidizing stable conforms with our superacidity criterion.

In continuation of recent work on the dielectric response imidazolium-based ionic liquids (ILs) (J. Phys. Chem. B, 2006, 110, 12682), we report effect cation variation frequency-dependent permittivity up to 20 GHz liquids. The salts are comprised pyrrolidinium, pyridinium, tetraalkylammonium, and triethylsulfonium cations combined with bis-((trifluoromethyl)sulfonyl)imide anion. spectra resemble those observed for imidazolium same all cases, major contribution results from a diffusive...

One of the remaining challenges in single-crystal structure refinement is proper description disorder crystal structures. This paper describes a computer program that performs semi-automatic modelling disordered moieties

Abstract Structures of the reactive intermediates (enamines and iminium ions) organocatalysis with diarylprolinol derivatives have been determined. To this end, methyl silyl ethers, 1 , aldehydes, PhCH 2 CHO, t BuCH PhCH=CHCHO, are condensed to corresponding enamines, A 3 ( Scheme ), cinnamoylidene salts, B 4 ). These isolated fully characterized by melting/decomposition points, [ α ] D elemental analysis, IR NMR spectroscopy, high‐resolution mass spectrometry (HR‐MS). Salts BF PF 6 SbF...

Vaporization enthalpy of an ionic liquid (IL) is a key physical property for applications ILs as thermofluids and also useful in developing state theories validating intermolecular potential functions used molecular modeling these liquids. Compilation the data homologous series 1-alkyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)imide ([C(n)mim][NTf2]) has revealed embarrassing disarray literature results. New experimental data, based on concurring results from quartz crystal...

One for all! On the basis of absolute chemical potential proton, a unified pH scale is introduced that universally applicable in gas phase, solution, and solid state. With this scale, it possible to directly compare acidities different media, give thermodynamically meaningful definition superacidity. This can be used all areas with variable proton activity. Detailed facts importance specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not...

After decades of vituperative debate over the classical or nonclassical structure 2-norbornyl cation, long-sought x-ray crystallographic proof bridged, geometry this prototype carbonium ion in solvated [C7H11](+)[Al2Br7](-) • CH2Br2 salt has finally been realized. This achievement required exceptional treatment. Crystals obtained by reacting norbornyl bromide with aluminum tribromide undergo a reversible order-disorder phase transition at 86 kelvin due to internal 6,1,2-hydride shifts cation...

Guilty as charged: Germanium(II) and tin(II) monocations which are stabilized by an extremely bulky amido ligand a very weakly coordinating anion reported (see picture; E=Ge, Sn; PF=[Al{OC(CF3)3}4]−). The metal centers exhibit weak intramolecular η2-arene interactions, preliminary reactivity studies highlight the electrophilicity of cations.

Abstract An einen Übersichtsartikel aus dem Jahre 2004 anknüpfend, wird hier über den strukturellen Aufbau, die Stabilität und Anwendungen moderner schwach koordinierender Anionen (weakly coordinating anions, WCAs) berichtet, aber auch Fortschritte der “klassischen” WCAs. In tabellarischer Form werden sowohl Ausgangsverbindungen zur Einführung einer Vielzahl von WCAs als deren physikochemische Eigenschaften zusammengefasst. Damit lässt sich für mögliche gut beurteilen, wie am besten in...

DFT calculations have been carried out for coordinatively saturated neutral and charged carbonyl complexes [M(CO)n]q where M is a metal atom of groups 2–10. The model compounds M(CO)2 (M = Ca, Sr, Ba) the experimentally observed [Ba(CO)]+ were also studied. bonding situation has analyzed with variety charge energy partitioning approaches. It shown that Dewar–Chatt–Duncanson in terms ← CO σ-donation → π-backdonation valid approach to explain M–CO bonds trend stretching frequencies. ligands...