Synthesis, structure and reactivities of the dinuclear mu-eta(1):eta(6)-arylethynyl ruthenium complexes [Cp(PR3)(2)Ru(mu-eta(1):eta(6)-C equivalent to CC6H4Me-p)RuCp*]center dot Cl (R = Ph, Me; Cp = eta(5)-C5H5, Cp* = eta(5)-C5Me5). The molecular structure of [Cp(PPh3)(2)Ru(mu-eta(1):eta(6)-C equivalent to CC6H4Me-p)RuCp*]center dot PF6

Treatment of [Cp(PR3)(2)Ru(C equivalent to CC6H4Me-p) (la, R = Ph Ib, R = M e; Cp = eta (5)-C5H5) with [Cp*Ru(mu (3). Cl)](4) (Cp* = eta (5)-C5Me5) sel ectively produced the novel dinuclear mu-eta (1):eta (6)- arylethynyl compl ex Cp(PR3)(2)Ru(mu-eta (1):eta (6)-C equivalent to CC6H4Me-p)RuCp*] (2 . Cl : 2a, R=Ph; 2b, R=Me). Protonation of 2 . OTf (OTf=OSO2CF3) by TfOH afforde d the corresponding vinylidene complex [Cp(PR3)(2)Ru(mu-eta (1):eta (6)-C=C HC6H4Me-p)RuCp*]. [OTf](2) (3 . [OTf](2): 3a, R = Ph; 3b, R = Me), which re generated 2 . OTf upon treatment with LiBHEt3. Reaction of 2a . Cl with I-2 and subsequent anion metathesis with AgBF4 produced the iodovinylidene com plex [Cp(PPh3)(2)Ru(mu-eta (1):eta (6)-C=CIC6H4Me-p)RuCp*]. [BF4](2) (4 . [ BF4](2)), whereas similar treatment of 2b . PF6 yielded the iodo/arylethyny l complex [Cp(I)(PMe3)(2)Ru(mu-eta (1):eta (6)-C equivalent to CC6H4Me-p)Ru Cp*]. [PF6](2) (5 . [PF6](2)). Substitution of one of the PPh3 ligands in 2 a . OTf proceeded under I atm of CO to form [Cp(PPh3)(CO)Ru(mu-eta (1):eta (6)-C equivalent to CC6H4Me-p)RuCp*]. OTf (6 . OTf). The molecular structur e of 2a . PF6 was determined by X-ray crystallography. (C) 2001 Elsevier Sc ience B.V. All rights reserved.