Acid-induced lsomerisations of osmium and ruthenium clusters involving hydroxide transfer from carbon to metal atoms. X-Ray crystal structure of nonacarbonyl-µ₃-(3,3-diphenylallene- 1,1-diyl)-µ-hydrido-µ-hydroxo-triosmium(2 Os–Os)

Abstract

The complexes [M3H(CO)9(p3-C-CCPh20H)] (M = Ru or 0s) were prepared by reaction of [M3(C0)&J with HOCPh2C-CCPh20H in saturated hydrocarbon at 130 "C for M = 0 s or in refluxing cyclohexane from M = Ru. In the latter case the yield of cluster is low and there is some 1 ,I ,4,4-tetraphenylbutadiene formed. Treatment of the trinuclear clusters in chloroform with trifluoroacetic acid leads to isomerisation with migration of the OH group from carbon to metal atoms. This was confirmed by an X-ray structure determination for the osmium productThe crystals are monoclinic, space group P2,, a = 10.569( 1), b = 20.259(3), c = 12.287(2) A, p = 95.66(1)", and 2 = 4. The structure was refined to R = 0.0621 for 4 11 2 observed reflections. There are two independent molecules (A and B) in the'unit cell with very closely similar structures. Spectroscopically, an OH group was identified and another hydrogen bound to osmium but neither hydrogen atom was located by X-ray diffraction. The OH group bridges two non-bonded osmium atoms separated by 3.374(5) A in molecule A [3.372(5) A in B], while the p-H was deduced to be across the longer 0s-0s bond [2.905(5) versus 2.861 (5) A for molecule A and 2.902(5) versus 2.869( 5) A for molecule B]. The 3,3-diphenylallene-I ,1 -diyl ligand is bonded through two 0s-C CT bonds and a 1,2-q2-co-ordination to the other osmium atom and is bent about the central atom [145(3)" for molecule A and 144(3)' for B]. The orientation of the phenyl substituents at the non-co-ordinated allene carbon atom agrees with this interpretation of the bonding.We have been interested in introducing hydroxy-or aminosubstituted alkynes into triruthenium and triosmium clusters

Nucleophilic addition at u 3 -alkyne clusters leading to carbon-carbon bond formation

“…The alkynyl cluster Os3H(CO)9(C=CC Ph2OH) undergoes an acid-catalysed isomerization to Os3H(OH)(CO)9-(G-G-GPh2) and it is likely that the unsaturated intermediate [Os3H(CO)9(C = C = C P h 2)]+ is attacked at the metal directly by OH -or H20 . Nucleophilic attack leads to an opening of one edge of the metal triangle (Aime et al 1982).…”

Activation of methanol in the reaction of [Fe3(CO)12] with 1-phenylprop-2-yn-1-ol; crystal structures of and chemical relationships between [Fe3(CO)9(μ-CO){(CC C(H)Ph}] and [Fe2(CO)6{Ph(H)CCCHC(OMe)O}]

“…To our knowledge, there are only two examples for this type of dehydration on metal clusters of the iron triad. The first was reported by Aime et al 7…”

Heterocyclic phosphorus ligands from cluster-bonded allenylidene

“…The reactions of M 3 (µ-H){µ 3 -C 2 CPh 2 (OH)}(CO) 9 (M = Ru, Os) with acid to give the diphenylallenylidene complexes M 3 (µ 3 -CCCPh 2 )(µ-OH)(CO) 9 were reported in 1982. 3 More recently, we have described similar reactions of Ru 3 (µ-H){µ 3 -C 2 CAr 2 -(OH)}(CO) 9 (Ar = Ph, p-tolyl) with dppm in the presence of HBF 4 ؒOMe 2 to give Ru 3 (µ 3 -CCCAr 2 )(µ-dppm)(CO) 8 , 4 which on heating undergo aryl group-migration reactions to the allenylidene ligand. 5 Further investigations of these reactions have revealed that similar reactions with the complex derived from propyn-1-ol take a different course.…”