ELECTROPHILIC REACTIVITY OF ARENE LIGANDS COORDINATED TO RUTHENIUM CARBIDO CLUSTER COMPLEXES

Addition of RLi (R = Ph, Me) to [Ru6C(CO)(14)(eta(6)-C6H6)] (1) or [Ru 6C(CO)(12)(eta(6)-C6H6) (mu(2)-eta(2):eta(2)-C6H8)] (2), followed by r eaction with [AuPPh3Cl]/TlPF6, leads to the formation of the mixed rut henium-gold cluster complexes [Ru6C(CO)(14)(eta(4)-C6H6R2) (AuPPh3)(2) ] (5a, b) and 6C(CO)(12)(eta(6)-C6H5R)(mu(2)-eta(2):eta(2)-C6H8) (AuPP h3)] (6a, b), respectively. Treatment of the likely intermediate produ cts, the cluster salts (PPN)(2)[Ru6C(CO)(14)(eta(4)-C6H6R2)] (3a, b) a nd (PPN)(2)[Ru6C(CO)(12)(eta(5)-C6H6R) (mu(2)-eta(2):eta(2)-C6H8)] (4a , b) (PPN = [N(PPh3)(2)](+)) with [CPh3][BF4] affords hydride abstract ion and gives the substituted arene cluster complexes [Ru6C(CO)(14)(et a(6)-C6H4R2)] (7a, b) and [Ru6C(CO)(12)(eta(6)-C6H5R) (mu(2)-eta(2):et a(2)-C6H8)] (8a, b), respectively. The crystal and molecular structure s of [Ru6C(CO)(14)(eta(6)-C6H4Ph2)] (7a) and of two polymorphs of [Ru6 C(CO)(14)(eta(6)-C6H4Me2)] (7b) are established by X-ray crystallograp hy. The molecules have a p-terphenyl (7a) and a p-xylene (7b) ligand e ta(6)-coordinated to a vertex of a Ru-6 octahedron. (C) 1998 Elsevier Science S.A. All rights reserved.