The cationic homo- and heteronuclearsandwich complexes (η5-cyclopentadienyl)(ferrocenylethynyl-η6-benzene)ruthenium(II) hexafluoridophosphate (3a), (η5-cyclopentadienyl)(ruthenocenylethynyl-η6-benzene)ruthenium(II) hexafluoridophosphate (3b), (η5-cyclopentadienyl)[1,4-bis(ferrocenylethynyl)-η6-benzene]ruthenium(II) hexafluoridophosphate (4a), (η5-cyclopentadienyl)[1,4-bis(ruthenocenylethynyl)-η6-benzene]ruthenium(II) hexafluoridophosphate (4b), and (η5-cyclopentadienyl)[1,3,5-tris(ferrocenylethynyl)-η6-benzene]ruthenium(II) hexafluoridophosphate (5) were synthesized by means of Stille cross-coupling reactionusing tri-n-butyl(metallocenylethynyl)stannaneas nucleophile and the appropriate (η5-cyclopentadienyl)(η6-iodobenzene)ruthenium(II) cations as electrophiles. As acatalyst, a Pd(0) complex, furnished with AsPh3ligands,was applied. The hitherto unknown iodobenzene complexes (η5-cyclopentadienyl)(1,4-η6-diiodobenzene)ruthenium(II)hexafluoridophosphate (1b) and (η5-cyclopentadienyl)(η6-1,3,5-triiodobenzene)ruthenium(II) hexafluoridophosphate(1c) as well as the described cationic homo- and heteronuclearsandwich complexes 3–5were fullycharacterized and investigated with respect to the second-harmonicgeneration by hyper-Rayleigh scattering. For complexes 1b, 1c, 3a, and 5X-ray structuredeterminations were performed. [ABSTRACT FROM AUTHOR]