Synthesis and properties of the weakly coordinating anion [Me3 NB12 Cl11 ](-).

The weakly coordinating anion Me3 NB12 Cl11 has been prepared by a simple two-step procedure. The anion Me3 NB12 Cl11 is easily obtained in batches of up to 20 g by chlorination of the known H3 NB12 H11 anion with SbCl5 at about 190 °C and subsequent N-methylation with methyl iodide. Starting from Na[Me3 NB12 Cl11 ], several synthetically useful salts with reactive cations (NO , Ph3 C , and (Et3 Si)2 H ) were prepared. Full spectroscopic (NMR, IR, Raman, TGA, MS) characterization and single-crystal X-ray diffraction studies confirmed the identity and purity of the products. The thermal, chemical, and electrochemical stability as well as the basicity of the Me3 NB12 Cl11 anion is similar to that of the structurally related weakly coordinating 1-carba-closo-dodecaborate and closo-dodecaborate anions. The facile preparation of the Me3 NB12 Cl11 anion and its ideal chemical and physical properties make it a cheap alternative to other classes of weakly coordinating anions.