Organic chemistry of dinuclear metal centres. Part 14. Synthesis, X-Ray structure, and reactivity of the ruthenium–ruthenium double-bonded complex [Ru₂(μ-CO)(μ-C₂Ph₂)(η-C₅H₅)₂]

Abstract

BS8 I TS Ultraviolet irradiation of the metallacycle [Ru,(CO)(~-CO){~-C(O)C,P~,}(~-C,H~),] (1 ) in tetrahydrofuran (thf) gives the complex [Ru,(p-CO)(p-C,Ph,)(q-C,H,),] (2), shown by X-ray diffraction to have a ruthenium-ruthenium double bond [Ru=Ru 2.505(1) A] bridged transversely by a diphenylacetylene ligand. The loss of two molecules of CO in forming (2) is reversible; under 100 atm of CO at 50 "C complex (2) is converted into (1 ) in 60% yield. Treatment of unsaturated complex (2) with diazoalkanes RCHN, (R = H, Me, or C0,Et) results in the corresponding uptake of two alkylidene units to form [Ru,(CO)(p-CHR){p-C(Ph)C(Ph)CHR}-(q-C5H5),], existing as isomers for R = M e or C0,Et due to differing orientations of the p-CHR substituent. The structure of [Ru,(CO) (p-CH,){p-C( Ph)C( Ph)CH,}(q-C,H,),] Ru( 1)-Ru(2) Ru( 1)-C(3) Ru( 1)-C( 1 1) Ru( 1)-C( 13) Ru( 1)-C( 15)

A comparison between the reaction of P2Ph4 with [{Co2(CO)6}2(μ-η2:μ-η2-HOCH2CCCCCH2OH)] and the reaction of [Co2(μ-PPh2)2(CO)6] with HOCH2CCCCCH2OH

“…No coupling was resolved between the geminal vinyl protons. This correlates with other l-CR=CH 2 vinyl ligands for which negligible, or only a small coupling is observed [22][23][24][25][26][27][28]. The CH 2 protons of the lactone ring are observed as multiplets at d 4.32 and 4.18 with a geminal H-H coupling of 14 Hz and smaller unresolved coupling to both phosphorus atoms.…”

CO Cleavage Promoted by Acetylide Addition to Vinyliminium Diiron Complexes

“…The Fe(2)-C(23) interaction is significantly longer than that of Fe(2)-C(12) and Fe(2)-C(21), suggesting that an alternative description of the bridging ligand is possible (Scheme 2, B). The C β -C γ -C δ sequence [C(23)-C(21)-C(12)] can be considered as a vinyl-substituted μ-alkylidene, which corresponds to a coordination mode commonly found in diiron [2] and diruthenium [3] complexes. However, because the C(12)-C(21) interaction [1.417(5) Å] is shorter than in C(21)-C(23) [1.455(6) Å] a description of the ligand as η 1 :η 2 -vinyl connected to an alkynyl and an amido-functionality also appears possible (structure C).…”

“…CO labelled [Fe 2 {μ-CN(Me)(Xyl)}(μ-CO)( 13 CO) 2 -(Cp) 2 ][SO 3 CF 3 ] into 13 C-labelled 2 was performed in further five steps, according to known procedures, [1,14] including the reaction described in this paper. …”

Photosubstitution of (Fulvalene)tetracarbonyldiruthenium by Alkenes and Alkynes: First Observation of Alkyne Coupling on Fulvalene Dimetals and Synthesis of a (Fulvalene)dimetallacyclopentadiene(alkene) Complex

“…The metallacyclopentadiene is characterized by marginal puckering . 24 While these data seem to suggest a metal-metal double bond for 6, there are other structures in which short single bonds in the same range occur, their occurrence rationalized by the bidentate effect of short bridges present. 25 In 6, compared to its (CpRu) 2 metallacyclopentadiene relatives, the Fv strain effect 2c would be expected to lengthen the Ru-Ru bond, an expectation at odds with reality.…”