ABSTRACT
The hydride-bridged silylium cation [Et3 Si-H-SiEt3 ]+ , stabilized by the weakly coordinating [Me3 NB12 Cl11 ]- anion, undergoes, in the presence of excess silane, a series of unexpected consecutive reactions with the valence-isoelectronic molecules CS2 and CO2 . The final products of the reaction with CS2 are methane and the previously unknown [(Et3 Si)3 S]+ cation. To gain insight into the entire reaction cascade, numerous experiments with varying conditions were performed, intermediate products were intercepted, and their structures were determined by X-ray crystallography. Besides the [(Et3 Si)3 S]+ cation as the final product, crystal structures of [(Et3 Si)2 SMe]+ , [Et3 SiS(H)Me]+ , and [Et3 SiOC(H)OSiEt3 ]+ were obtained. Experimental results combined with supporting quantum-chemical calculations in the gas phase and solution allow a detailed understanding of the reaction cascade.
ABSTRACT
Noble gas (Ng) containing molecular anions are much scarcer than Ng containing cations. No neon containing anion has been reported so far. Here, the experimental observation of the molecular anion [B12(CN)11Ne]- and a theoretical analysis of the boron-neon bond is reported.
ABSTRACT
In the title compound, Na+[Me3NB12Cl11]-·SO2 [systematic name: sodium 1-(trimethylammonio)-undeca-chloro-closo-dodeca-borate sulfur dioxide], the SO2 mol-ecule is η 1-O-coordinated to the Na+ cation. Surprisingly, the SO2 mol-ecule is more weakly bound to sodium than is found in other sodium-SO2 complexes and the SO2 mol-ecule is essentially undistorted compared to the structure of free SO2. The Na+ cation has a coordination number of eight in a distorted twofold-capped trigonal prism and makes contacts to three individual boron cluster anions, resulting in an overall three-dimensional network. Although the number of known η 1-O-coordinated SO2 complexes is growing, sodium-SO2 complexes are still rare.
ABSTRACT
Chemically binding to argon (Ar) at room temperature has remained the privilege of the most reactive electrophiles, all of which are cationic (or even dicationic) in nature. Herein, we report a concept for the rational design of anionic superelectrophiles that are composed of a strong electrophilic center firmly embedded in a negatively charged framework of exceptional stability. To validate our concept, we synthesized the percyano-dodecoborate [B12(CN)12]2-, the electronically most stable dianion ever investigated experimentally. It serves as a precursor for the generation of the monoanion [B12(CN)11]-, which indeed spontaneously binds Ar at 298 K. Our mass spectrometric and spectroscopic studies are accompanied by high-level computational investigations including a bonding analysis of the exceptional B-Ar bond. The detection and characterization of this highly reactive, structurally stable anionic superelectrophile starts another chapter in the metal-free activation of particularly inert compounds and elements.