57673-31-1Relevant articles and documents
Reactivity of a triruthenium acetylide complex toward alkynes and the silica-mediated dehydration of cluster-bound alkynols: X-ray crystal structures of the novel butadienyl species [Ru3(CO)8{μ3-η8-C(But)qqCC(Ph)qqC(H) Ph}] and the unusual complex [Ru3(CO)5(μ-CO)
Charmant, Jonathan P. H.,Davies, Guy,King, Philip J.,Wigginton, James R.,Sappa
, p. 2330 - 2340 (2000)
The lightly ligated complex [Ru3(CO)8(MeCN)(μ-H)(μ-C2But)] (4), derived from [Ru3(CO)9-(μ-H) (μ-C2But)](1), reacts with terminal alkynes and alkynols under very mild conditions to give high yields of products derived from addition of three molecules of alkyne/alkynol. More interestingly, complex 4 also reacts with diphenylacetylene to form the novel butadienylic species [Ru3(CO)8{μ3- η8-C(But)qqCC(Ph)qqC(H)Ph}] (6), stabilized by an uncommon interaction between a phenyl substituent and a cluster metal atom. Its formation represents a key step in understanding the reaction mechanism leading to tri- and tetra-alkyne-substituted derivatives. The acetonitrile derivative of 6 reacts further with diphenylacetylene to afford the complex [Ru3(CO)7 {μ3-η8-C(But)qqCC(Ph)qqC(H)Ph} {μ3-η4-C(Ph)qqC(Ph)}] (7), which, upon heating, isomerizes to give [Ru3(CO)7{μ3- η8-C(But)qqCC(Ph)qqC(Ph)H}{μ3-η4- C(Ph)qqC(Ph)}]-(2) in high yield. The analogous complex [Ru3(CO)7{μ3-η8-C(But)qqCC(Ph)qqC (CPh2OH)H}-{μ3-η4-C(CPh2OH)qqC (Ph)}] (8) is formed directly from 4 through reaction with 1,1,3-triphenyl-2-propyn-1-ol. Finally, the tetra-alkyne-substituted metallacyclic complex [Ru3(CO)6-{μ3-η6- C(But)CC(CPh2OH)CH2}{μ3-η6- CHC(CPh2OH)COC(CPh2OH)CH}] (5a), obtained from reaction of 1,1-diphenyl-2-propyn-1-ol with 4, undergoes facile dehydration in the presence of silica gel to yield the cluster complex [Ru3(CO)5(μ-CO){μ3-η5-CC(But)OC (Ph)2CCH}{μ3-η6-CHC(CPh2OH)COC(CPh2) CH}] (9), a process that involves formation of an unusual heterocycle. In addition, complex 9 contains a terminal carbene unit, one of the first examples of such a ligand in a cluster complex. The structures of complexes 6, 8, and 9 have been determined crystallographically and are discussed in association with possible reaction mechanisms.
Reactivity and ligand dynamics of a skeletally chiral metal cluster: [(μ3-η2-C2tBu)(CO) 9Ru3]2(μ4-Hg)
Hajela, Sharad,Novak, Bruce M.,Rosenberg, Edward
, p. 468 - 475 (2008/10/08)
The reaction chemistry and ligand dynamics of [Ru3(CO)9(μ3-η2-C 2tBu)]2(μ4-Hg) (3) have been studied. It has been found that phosphine substitution can be affected thermally, photochemically and by electron transfer. In all cases the same substitution products are observed: [Ru3(CO)9(μ3-η2-C 2tBu)](μ4-Hg)-[(Ru3(CO) 8(μ3-η2-C2 tBu)(PPh3)] (4a), [Ru3(CO)8(μ3-η2-C 2tBu)(PPh3)]2(μ4-Hg) (4b), and [Ru3(CO)8(μ3-η2-C 2tBu)(PPh3)](μ4-Hg)[Ru 3(CO)7(μ3-η2-C 2tBu)(PPh3)2] (4c). Compound 3 shows high thermal stability with respect to reductive elimination of Hg metal. However, redistribution reactions occur at elevated temperatures. The redistribution equilibrium constant is found to be 0.10 at 80°C for the monophosphine derivative [Ru3(CO)9(μ3-η2-C 2tBu)](μ4-Hg)[Ru3(CO) 8(μ3-η2-C2 tBu)(P(Ph)2(CH2CH2COOC 2H5))] (4d). The thermal reaction of 3 with H2 gives H3Ru3(CO)9(μ3-η 1-CCH2C(CH3)3) (5), HRu3(CO)9(μ3-η2-C 2tBu) (1), H4Ru4(CO)12, and Hg metal as the major products. The photochemical reaction of 3 and H2 yields the same products except H4Ru4(CO)12 is not produced under these conditions. When 3 is reacted with zinc metal, transmetalation is observed to give [Ru3(CO)9(μ3-η2-C 2tBu)2](μ4-Zn) and Hg metal. Reaction of 3 with Br2 gives the cleavage product (CO)9(μ3-η2-C2 tBu)Ru3HgBr (2b) while reaction with HCl gives 1 and (μ3-η2-C2tBu)(CO) 9Ru3HgCl (2c). Variable-temperature 13C and 31P NMR of 3, 4a, and 4b reveal axial-radial exchange processes similar to those observed for related compounds. Variable-temperature 31P NMR of a mixture of the diastereomers of [Ru3(CO)9(μ3-η2-C 2tu)](μ4-Hg)[Ru3(CO) 8(μ3-η2-C2 tBu)(P-(CH3)(C6H5CH 2)(C6H5))] (4f and 4f′) shows racemization at high temperatures which is interpreted as a rearrangement of the metal skeleton from its chiral ground state to a symmetrical structure containing a face-bridging mercury.
