Direct Preparation of [Ru(η2‐O2CO)(η6‐arene)(L)] Carbonate Complexes (L = Phosphane, Carbene) and Their Use as Precursors of [RuH2(p‐cymene)(PCy3)] and [Ru(η6‐arene)(L)(MeCN)2][BF4]2: X‐ray Crystal Structure Determination of [Ru(η2‐O2CO)(p‐cymene)(PCy3)]·1/2CH2Cl2 and [Ru(η2‐O2CO)(η6‐C6Me6)(PMe3)]·H2O

Abstract

Abstract[RuCl2(η6‐arene)(PR3)] complexes react with K2CO3 in the presence of water to afford the carbonatoruthenium(II) derivatives [Ru(η2‐O2CO)(η6‐arene)(PR3)] (2; arene = p‐cymene, R = Cy, Ph, or Me; arene = hexamethylbenzene, R = Me) involving a planar Ru(η2‐O2CO) moiety as shown by X‐ray crystal structure determination of 2a (p‐cymene, PCy3) and 2d (hexamethylbenzene, PMe3). The complex [Ru(η2‐O2CO)(p‐cymene)(PCy3)] is cleanly converted in hot methanol into the dihydride [RuH2(p‐cymene)(PCy3)]. The related complexes [Ru(η2‐O2CO)(η6‐arene)(IMes)] [arene = p‐cymene or hexamethylbenzene, IMes = 1,3‐bis(2,4,6‐trimethylphenyl)imidazol‐2‐ylidene] are straightforwardly prepared by treating [RuCl2(η6‐arene)]2 precursors with 1,3‐bis(2,4,6‐trimethylphenyl)imidazolium chloride and K2CO3 in THF at reflux. The removal of the carbonato ligand from complexes 2 with HBF4 in the presence of acetonitrile leads to the dicationic derivatives [Ru(η6‐arene)(L)(MeCN)2][BF4]2 (L = PR3 or IMes). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)