B‐Substituted (Arene)ruthenacarborane–Sulfonium, –Thioether and–Mercaptan Complexes: Mild Single and Double Dealkylation and Structural Implications in the Antipodal Distance

Abstract

AbstractReactions of [RuCl2(η6‐arene)]2 (arene = benzene, p‐cymene) with nido‐[7‐R‐10‐L‐7,8‐C2B9H9]– in THF at room temperature for 3 d give the (arene)ruthenacarborane complexes closo‐[3‐Ru(η6‐arene)‐1‐R‐8‐L‐1,2‐C2B9H9]+ {arene = benzene, R = H [L = Me2S (1a), THT (1b), EtPhS (1c)], R = Me [L = Me2S (2a)]; arene = p‐cymene, R = H [L = Me2S (3a)]} and mercaptan closo‐[3‐Ru(η6‐arene)‐1‐R‐8‐HS‐1,2‐C2B9H9] [arene = benzene, R = H (4), Me (5); arene = p‐cymene, R = H (6)] in yields of 20–40 % and 22–29 %, respectively. The asymmetric ligand nido‐[9‐Me2S‐7,8‐C2B9H10]– leads to the thioether complex closo‐[3‐Ru(η6‐benzene)‐7‐MeS‐1,2‐C2B9H10] (8) in 34 % yield under the same reaction conditions. The crystal structure of 1a is described and compared with those of 4 and 8. The fully assigned 11B NMR spectroscopic data for a whole series of ruthenacarboranes having B‐substituted sulfonium, thioether and mercaptan groups are presented. These data show a relation between antipodal cluster atom distances (antipodal distance) and antipodal effect (AE) in the crystal structures of these complexes and for other families of heteroboranes such as closo‐[EB11H11] and closo‐[EB9H9]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)