(1,2,3,4,7-Pentamethylindenyl)rhodium complexes with arene ligands

The reaction of (eta(5)-C9H2Me5)Rh(1,5-C8H12) (1) with I-2 gives the iodide complex [(eta(5)-C9H2Me5)RhI2](2) (2). The solvate complex [(eta 5-C9H2Me5)Rh(MeNO2)(3)](2+) (generated in situ by treatment of 2 with Ag+ in nitromethane) reacts with benzene and its derivatives giving the dicationic arene complexes [(eta(5)-C9H2Me5)Rh(arene)](2+) [arene = C6H6 (3a), C6Me6 (3b), C6H5OMe (3c)]. Similar reaction with the borole sandwich compound CpRh(eta(5)-C4H4BPh) results in the arene-type complex [CpRh(mu-eta(5):eta(6)-C4H4BPh)Rh(eta(5)-C9H2Me5)](2+) (4). Treatment of 2 with CpT1 in acetonitrile affords cation [(eta(5)-C9H2Me5)RhCp](broken vertical bar) (5). The structure of [3c](BF4)(2) was determined by X-ray diffraction. The electrochemical behaviour of complexes prepared was studied. The rhodium-benzene bonding in series of the related complexes [(ring)Rh(C6H6)](2+) (ring = Cp, Cp*, C9H7, C9H2Me5) was analyzed using energy and charge decomposition schemes. (C) 2007 Elsevier B.V. All rights reserved.