Alkynethiolato and alkyneselenolato complexes of ruthenium, CpRu(PPh3)(2)(EC equivalent to CR) (Cp = eta -C5H5 E = S, R = Ph (1a), SiMe3 (1b), 'Bu (1c); E = Se, R = Ph (2a), SiMe3 (2b)), were synthesized by the reactions of CpRuCl-(PPh3)(2) with corresponding lithium alkynechalcogenolates in THF. An analogous reaction of Cp*RuCl(PEt3)(2) (CP* = eta (5)-C5Me5) with LiSC equivalent to CPh produced Cp*Ru(PEt3)(2)(SC equivalent to CPh) (3). Complexes 1a and 2a were allowed to react in THF with "Cp2Zr", generated in situ from Cp2ZrCl2 and 2 equiv of n-BuLi from which the S-bridged Ru-Zr dinuclear complexes CpRu(PPh3)(C equivalent to CPh)(mu -S)ZrCp2 (4a) and CpRu(PPh3)(C equivalent to CPh)(mu -Se)ZrCp2 (4b) were isolated, respectively. In these complexes, C-S(Se) bond cleavage of the alkynechalcogenlate ligands was promoted by "Cp2Zr", and the Zr atom was oxidized from II to IV, Treatment of 4a and 4b in THF under 1 atm CO gave rise to CpRu(CO)(C equivalent to CPh)(mu -E)ZrCp2 (E = S (5a), Se (5b)), while addition of tert-butyl isocyanide to a THF solution of 4b afforded CpRu(CN'Bu)(C equivalent to CPh)(mu -Se)ZrCp2 (6). The crystal structures of 1a, 1c, 2a, 2b, 3, 4a, 4b, and 5b were determined by X-ray diffraction analysis.