The closo-dodecahydrododecaborate [NEt3H]2[B12H12] has been prepared on a lab scale by an improved synthesis from cheap and readily available starting materials Na[BH4] and I2 in diglyme (diethylene glycol dimethyl ether). Subsequent chlorination with elemental chlorine in aqueous solution at normal pressure yielded the per-chlorinated weakly coordinating [B12Cl12]2- anion. By simple metathesis reaction a variety of useful salts [cation]2[B12Cl12] (cation=[NEt3H]+, [NBu4]+, Li+, Na+, K+, Cs+) is available. These salts are useful starting materials, which have the potential to open up the chemistry of [B12Cl12]2- as a weakly coordinating dianion. Exemplarily, they were used in further reactions to prepare [NO]2[B12Cl12], [PPN]2[B12Cl12], and [CPh3]2[B12Cl12]. The crystal structures of Cs2[B12Cl12].SO2, [CPh3]2[B12Cl12].2C2H4Cl2, and [CPh3]2[B12Cl12].2SO2 and preliminary crystal structures of [NO]2[B12Cl12].SO2 and [PPN]2[B12Cl12].CH2Cl2 were determined. The crystal structure of the SO2 solvate Cs2[B12Cl12].SO2 is related to the crystal structure of solvent free Cs2[B12Cl12]. [CPh3]2[B12Cl12].2C2H4Cl2 and [CPh3]2[B12Cl12].2SO2 have very similar structures in the solid state. In both cases the [CPh3]+ cations form only very weak contacts to the [B12Cl12]2- anion and SO2 or C2H4Cl2 solvent molecules respectively. The averaged experimental B-B (178.7 pm) and B-Cl (178.9 pm) bond lengths within [B12Cl12]2- are essentially unchanged in all determined structures and are reproduced well by PBE0/TZVPP quantum chemical calculations (B-B 178.6 pm, B-Cl 179.3 pm). All results indicate that [B12Cl12]2- is a readily accessible weakly-coordinating dianion.

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We report herein the synthesis and full characterization of the donor-free Lewis superacids Al(OR(F))(3) with OR(F) = OC(CF(3))(3) (1) and OC(C(5)F(10))C(6)F(5) (2), the stabilization of 1 as adducts with the very weak Lewis bases PhF, 1,2-F(2)C(6)H(4), and SO(2), as well as the internal C-F activation pathway of 1 leading to Al(2)(F)(OR(F))(5) (4) and trimeric [FAl(OR(F))(2)](3) (5, OR(F) = OC(CF(3))(3)). Insights have been gained from NMR studies, single-crystal structure determinations, and DFT calculations. The usefulness of these Lewis acids for halide abstractions has been demonstrated by reactions with trityl chloride (NMR; crystal structures). The trityl salts allow the introduction of new, heteroleptic weakly coordinating [Cl-Al(OR(F))(3)](-) anions, for example, by hydride or alkyl abstraction reactions.

Upon reaction of gaseous Me3SiF with the in situ prepared Lewis acid Al(OR(F))3, the stable ion-like silylium compound Me3 Si-F-Al(OR(F))3 1 forms. The Janus-headed 1 is a readily available smart Lewis acid that differentiates between hard and soft nucleophiles, but also polymerizes isobutene effectively. Thus, in reactions of 1 with soft nucleophiles (Nu), such as phosphanes, the silylium side interacts in an orbital-controlled manner, with formation of [Me3Si-Nu](+) and the weakly coordinating [F-Al(OR(F))3](-) or [((F)RO)3Al-F-Al(OR(F))3](-) anions. If exchanged for hard nucleophiles, such as primary alcohols, the aluminum side reacts in a charge-controlled manner, with release of FSiMe3 gas and formation of the adduct R(H)O-Al(OR(F))3. Compound 1 very effectively initiates polymerization of 8 to 21 mL of liquid C4 H8 in 50 mL of CH2 Cl2 already at temperatures between -57 and -30 °C with initiator loads as low as 10 mg in a few seconds with 100% yield but broad polydispersities.

Several, partly new, ionic liquids (ILs) containing imidazolium and ammonium cations as well as the medium-sized [NTf2 ](-) (0.230 nm(3) ; Tf=CF3 SO3 (-) ) and the large [Al(hfip)4 ](-) (0.581 nm(3) ; hfip=OC(H)(CF3 )2 ) anions were synthesized and characterized. Their temperature-dependent viscosities and conductivities between 25 and 80 °C showed typical Vogel-Fulcher-Tammann (VFT) behavior. Ion-specific self-diffusion constants were measured at room temperature by pulsed-gradient stimulated-echo (PGSTE) NMR experiments. In general, self-diffusion constants of both cations and anions in [Al(hfip)4 ](-) -based ILs were higher than in [NTf2 ](-) -based ILs. Ionicities were calculated from self-diffusion constants and measured bulk conductivities, and showed that [Al(hfip)4 ](-) -based ILs yield higher ionicities than their [NTf2 ](-) analogues, the former of which reach values of virtually 100 % in some cases.From these observations it was concluded that [Al(hfip)4 ](-) -based ILs come close to systems without any interactions, and this hypothesis is underlined with a Hirshfeld analysis. Additionally, a robust, modified Marcus theory quantitatively accounted for the differences between the two anions and yielded a minimum of the activation energy for ion movement at an anion diameter of slightly greater than 1 nm, which fits almost perfectly the size of [Al(hfip)4 ](-) . Shallow Coulomb potential wells are responsible for the high mobility of ILs with such anions.

The perhalogenated closo-dodecaborate dianions [B12 X12 ](2-) (X=H, F, Cl, Br, I) are three-dimensional counterparts to the two-dimensional aromatics C6 X6 (X=H, F, Cl, Br, I). Whereas oxidation of the parent compounds [B12 H12 ](2-) and benzene does not lead to isolable radicals, the perhalogenated analogues can be oxidized by chemical or electrochemical methods to give stable radicals. The chemical oxidation of the closo-dodecaborate dianions [B12 X12 ](2-) with the strong oxidizer AsF5 in liquid sulfur dioxide (lSO2 ) yielded the corresponding radical anions [B12 X12 ](⋅-) (X=F, Cl, Br). The presence of radical ions was proven by EPR and UV/Vis spectroscopy and supported by quantum chemical calculations. Use of an excess amount of the oxidizing agent allowed the synthesis of the neutral perhalogenated hypercloso-boranes B12 X12 (X=Cl, Br). These compounds were characterized by single-crystal X-ray diffraction of dark blue B12 Cl12 and [Na(SO2 )6 ][B12 Br12 ]⋅B12 Br12 . Sublimation of the crude reaction products that contained B12 X12 (X=Cl, Br) resulted in pure dark blue B12 Cl12 or decomposition to red B9 Br9 , respectively. The energetics of the oxidation processes in the gas phase were calculated by DFT methods at the PBE0/def2-TZVPP level of theory. They revealed the trend of increasing ionization potentials of the [B12 X12 ](2-) dianions by going from fluorine to bromine as halogen substituent. The oxidation of all [B12 X12 ](2-) dianions was also studied in the gas phase by mass spectrometry in an ion trap. The electrochemical oxidation of the closo-dodecaborate dianions [B12 X12 ](2-) (X=F, Cl, Br, I) by cyclic and Osteryoung square-wave voltammetry in liquid sulfur dioxide or acetonitrile showed very good agreement with quantum chemical calculations in the gas phase. For [B12 X12 ](2-) (X=F, Cl, Br) the first and second oxidation processes are detected. Whereas the first process is quasi-reversible (with oxidation potentials in the range between +1.68 and +2.29 V (lSO2 , versus ferrocene/ferrocenium (Fc(0/+) ))), the second process is irreversible (with oxidation potentials ranging from +2.63 to +2.71 V (lSO2 , versus Fc(0/+) )). [B12 I12 ](2-) showed a complex oxidation behavior in cyclic voltammetry experiments, presumably owing to decomposition of the cluster anion under release of iodide, which also explains the failure to isolate the respective radical by chemical oxidation.

The step-change in gravimetric energy density needed for electrochemical energy storage devices to power unmanned autonomous vehicles, electric vehicles, and enable low-cost clean grid storage is unlikely to be provided by conventional lithium ion batteries. Lithium-sulfur batteries comprising lightweight elements provide a promising alternative, but the associated polysulfide shuttle in typical ether-based electrolytes generates loss in capacity and low coulombic efficiency. The first new electrolyte based on a unique combination of a relatively hydrophobic sulfonamide solvent and a low ion-pairing salt, which inhibits the polysulfide shuttle, is presented. This system behaves as a sparingly solvating electrolyte at slightly elevated temperatures, where it sustains reversible capacities as high as 1200-1500 mAh g over a wide range of current density (2C-C/5, respectively) when paired with a lithium metal anode, with a coulombic efficiency of >99.7 % in the absence of LiNO additive.

Compounds containing boron atoms as spin carriers have recently received attention.[1] The icosahedral closo-dodecaborate ion [B 12 H 12 ] 2À is the archetypal boron cluster, and thus of special interest. Whereas the parent cluster [B 12 [3]Alkoxy-substituted ions [B 12 (OR) 12 ] 2À are oxidized at an even lower potential and even neutral B 12 (OR) 12 could be prepared.[4] Very recently, the perhydroxylated radical [B 12 (OH) 12 ]C À has been prepared and structurally characterized.[5] Smaller perhalogenated polyborane cluster radical anions [B n X n ]C À (X = H, Cl, Br, I; n = 6, 8-10), which are derived by one-electron oxidation from the corresponding closo clusters have been prepared and characterized by chemical and electrochemical methods. [6] Halogen substitution and an increasing cluster size significantly increase the resistance to oxidation and consequently the perhalogenated dodecaborates [B 12 X 12 ] 2À (X = halogen) are much more difficult to oxidize. Oxidation of dodecaborates [B 12 X 12 ] 2À (X = H, F, Cl, Br) to give the corresponding radical anions [B 12 X 12 ]C À has been investigated theoretically [7] and by electrochemical methods.[ [9] whilst in earlier electrochemical investigations, the derivatives containing heavier halogens (X = Cl, Br) did not have a well-defined oxidation wave in acetonitrile. [2a, 11] In a recent review, Kaim et al. stated that "Although the oxidation of [B 12 X 12 ] 2À