Slipped μ‐Indenyl Triple‐Decker Complexes Containing (C₄Me₄)Co and (C₅R₅)Ru Fragments

Abstract

Slipped triple‐decker complexes with a bridging indenyl ligand, namely [Cb*Co(μ:η5:η6‐C9H7)CoCb*]+ (2, Cb* = C4Me4) and [Cb*Co(μ:η5:η6‐C9H7)Ru(C5R5)]+ (R = H, 5a; Me, 5b), have been synthesised by electrophilic stacking of [Cb*Co(η5‐C9H7)] (1) with [Cb*Co(MeCN)3]+ or [(C5R5)Ru(MeCN)3]+ (R = H, Me), respectively. A similar reaction of [(C5R5)Ru(η5‐C9H7)] (R = H, 3a; Me, 3b) with [Cb*Co(MeCN)3]+ affords the cations [(C5R5)Ru(μ:η5:η6‐C9H7)CoCb*]+ (R = H, 4a; Me, 4b), which are isomeric with 5a,b. Stacking of [Ru(η5‐C9H7)2] (7) with [Cb*Co(MeCN)3]+ or [Cb*CoI]x/TlBF4 gives the triple‐decker complex [(η5‐C9H7)Ru(μ:η5:η6‐C9H7)CoCb*]+ (8). Further reaction of 8 with [Cp*RuCl]4/TlBF4 unexpectedly affords the slipped tetra‐decker ruthenium complex [Cp*Ru(μ:η5:η6‐C9H7)Ru(μ:η5:η6‐C9H7)RuCp*]2+ (11). The structures of [4b][Co(η‐7,8‐C2B9H11)2] and [Cp*Ru(η6‐C9H7)] (6) have been determined by X‐ray diffraction, and the electrochemical behaviour of the complexes prepared has been studied. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthesis of cationic complexes [(C4Me4)CoL]+ (L is naphthalene, phenanthrene, and anthracene)

“…We have previously 8, 13 shown that the acetonitrile complex [Cb*Co(MeCN) 3 ] + (1) can be used as a synthon for the [Cb*Co] + cation under mild conditions due to lability of the acetonitrile ligands. In this work, the reac tions of compound 1 with naphthalene and phenanthrene in nitromethane afforded the cationic complexes [Cb*Co(naphthalene)] + (2) and [Cb*Co(phenanthrene)] + (3) (Scheme 1).…”

“…1- 6 We have recently de scribed the efficient methods for the syntheses of the co balt tetramethylcyclobutadiene complexes with five elec tron ligands of different types. [7][8][9][10][11][12][13] In this work, we syn thesized the [Cb*CoL] + complexes (Cb* = C 4 Me 4 , L is polyarene).…”

Synthesis and structure of mono- and dinuclear cyclopentadienyl–indenyl complexes of iron(II) and further reactions to mixed tri- and tetranuclear iron–cobalt complexes

“…Hence, a significant elongation of the respective bond, as it had been reported for slipped triple-decker complexes bearing an indenyl bridge in a l-g 5 :g 6 bonding mode [15,16], is not observed in the structure of rac-3. This fact may be ascribed to the different bonding situation of the junction carbon atoms in rac-3, which do not bridge two metal centers, but are coordinated exclusively to the respective Fe atoms.…”

“…However, it is noteworthy to mention that in a recent study on indenyl-bridged diruthenium complexes a similar loss of electrochemical reversibility in respect to mononuclear precursor complexes had been observed [16].…”

“…The presence of two fused psystems in the indenyl system enables this bicyclic arene to act as a bridging ligand in homo-and heterobinuclear complexes [L n M(lg:g-ind)M 0 L 0 n ]. However, examples for such a bridging coordination mode are still relatively rare [9][10][11][12][13][14], and especially in the area of multidecker sandwich complexes the number of structurally characterized examples is limited to few examples in which indenyl acts as a central l-g 5 :g 6 -bridge between [(g 5 -C 5 (R) 5 )Ru] (R = H, CH 3 ) and [(g 4 -C 4 (CH 3 ) 4 )Co] fragments [15,16].…”