Further observations on the dimerisation of alkynes on triruthenium clusters

Reactions of Cyclotetradeca-1,8-diyne with Triosmium Carbonyl Clusters

“…Photoirradiation of 1 in the presence of C 14 H 20 ligand affords the osmacyclopentadienyl complex Os 3 (CO) 9 ( μ - η 4 -C 4 (C 12 H 20 ) 2 ) ( 4 ) in 48% yield, whereas co-thermolysis of 1 and C 14 H 20 produces mainly 2 . Similar metallacyclopentadienyl complexes were obtained from thermal reactions of Os 3 (CO) 10 ( μ 3 - η 2 -C 2 R 2 ) with C 2 R 2 (R = Ph, Me) − and of Ru 3 (CO) 8 ( μ -dppm)( μ 3 - η 2 -C 2 (CO 2 Me) 2 ) with C 2 Ph 2 …”

Reactions of the cluster complex [Ru5(μ5-C2)(μ-SMe)2(μ-PPh2)2(CO)11] with terminal alkynes HCCR (R = Ph, But or SiMe3)

“…Recent calculations suggest that electron density is concentrated on C(2), making it particularly prone to attack by electrophiles. 8 The present account confirms that this reactivity extends to alkynes, with ready formation of Table 2 Selected bond distances (Å) and angles (Њ) for complexes 5, 7, 9, 10 and 14 a new C-C bond and incorporation of the alkyne into a metallacycle occurring during the reaction. The reactions described above are summarised in Scheme 1.…”

“…With five M-M bonds, the cluster valence electron (c.v.e.) count of 80 [5Ru (40) ϩ 10CO (20) ϩ 2SMe (6) ϩ 2 PPh 2(6) ϩ the organic ligand(8)] is that expected by conventional cluster electron counting rules.…”

Carbon Chain Formation on Metallic Arrays. X-ray Structural Determinations of [Ru4(μ4-(CCC(CO2Me)C(CO2Me))(η-C5H4R)2(μ-CO)(CO)8], [{Ru(CO)2(η-C5H5)}2{μ-CCC(CO2Me)C(CO2Me)C(O)}], and [{Ru(CO)2(η-C5H5)2{μ-CC(CN)2CC(CN)2}] (R = H, Me)

“…The considerably distorted metallacycle bonds through all five members to Ru(3) and has recent precedent in the literature. [26][27][28][29][30][31][32][33][34] The ring is triply substituted with two carboxymethyl substituents at C(3) and C(4) and one Ru(CO) 2 (η-C 5 H 4 Me) moiety bound to C(2). The other Ru(CO) 2 (η-C 5 H 4 Me) group can be considered to bridge one edge of the metallacyclopentadiene with a bridging carbonyl ligand being found across the metal-metal bond, between Ru(1) and Ru(2).…”