Coupling of acetylene molecules on ruthenium clusters, involving cleavage of C–Si bonds in the alkyne and coordination of a phenyl ring of a SiPh3 group

Abstract

The reaction of [Ru3(CO)12] with the disubstituted acetylene Me3SiC≡CSiMe3 yields several compounds where cleavage of the C-Si bond has occurred thus allowing an easy coupling of carbon fragments to produce allene complexes [Ru4(CO)12(μ4-η(3)-Me3SiCCCSiMe3)] (2), differently substituted metallacycle compounds [Ru3(μ2-CO)2(CO)6{μ3-C(R)C(SiMe3)C(R')C(SiMe3)}] (3) [R = SiMe3, R' = CH3 (3a); R = H, R' = CH3 (3b); R = C≡CSiMe3; R' = H (3c)] and a pentanuclear ruthenium cluster containing three separate alkyne units; two with one SiMe3 substituent and one with two SiMe3 substituents, coordinated to the metal framework [Ru5(CO)12{μ3-(C2SiMe3)2}μ2-C2(SiMe3)2] (4). Another product of the reaction is the acetylide derivative [(μ-H)Ru3(CO)9(CCSiMe3)] (1a). In order to determine if this was an intermediate for the formation of the products already mentioned, the reaction of this compound was carried out with the two terminal alkynes HCCSiMe3 and HCCSiPh3. In the case of the reaction with the SiMe3 derivative, products included the same metallocyclopentadiene derivatives as well as the pentanuclear cluster already mentioned. If the acetylene is the SiPh3 derivative, products show coupling of SiPh3CC units with CCSiMe3 fragments and CO molecules, coordinated to mononuclear [Ru(CO)2(CCSiPh3){η(5)-(CCSiPh3)2C(OH)}] (7), dinuclear [Ru2(CO)3{Ph3Si(H)CC(H)CC(SiMe3)C(O)C(SiPh3)C(H)}] (8) and trinuclear [Ru3(CO)4{(Ph3Si(H)CC(H)CC(SiMe3)}{(H)CC(SiPh3)C(O)}] (9) clusters. One important characteristic in compounds 8 and 9 is that one of the phenyl rings of the SiPh3 substituent is η(6) coordinated to a ruthenium atom. Compounds 2 to 4(a-c) and 7 to 9 were characterized spectroscopically and by X-ray diffraction.

The aromatic dianion metalloles

“…Following a similar strategy to that with Fe, the triple-decker ruthenacycle 43 could be prepared ( Scheme 22 ). 33 …”

Metallaaromatic Chemistry: History and Development

“…For example, although dilithio ferrallole and dilithio ruthenallole have not been reported, some triple-decker analogues have been synthesized accidentally. − For example, thermal treatment of Fe 3 (CO) 12 with HCCSiPh 3 or HCCSiMe 3 provided 383 and 384 with a reverse-sandwich structure, respectively, albeit both in very low yields, together with several other products (Scheme ). The reaction of Ru 3 (CO) 12 with Me 3 SiCCSiMe 3 was somewhat different, giving several additional products, including three triple-decker ruthenium complexes with structures similar to 383 and 384 , involving CSi cleavage . In addition, Loginov and co-workers isolated the Rh complex 385 with a yield of lower than 1%, from the reaction of 1-methyl-3-borolene with [(C 2 H 4 ) 2 RhCl] 2 (Figure ).…”

“…386 The reaction of Ru 3 (CO) 12 with Me 3 SiCCSiMe 3 was somewhat different, giving several additional products, including three triple-decker ruthenium complexes with structures similar to 383 and 384, involving CSi cleavage. 387 In addition, Loginov and co-workers isolated the Rh complex 385 with a yield of lower than 1%, from the reaction of 1-methyl-3borolene with [(C 2 H 4 ) 2 RhCl] 2 (Figure 21). 388 21).…”

A Pd Halide Cluster from 1964: Pd6Cl8 Capped by Ring-Opened C3Ph3 Ligands from Oxidative Addition of Cyclopropenium Ions

“…3.31 Å in the literature). , For these Pd···Pd distances the range is much broader than in the literature with very close interactions between Pd2···Pd3 and Pd5···Pd6 (2.8552(6) and 2.8447(7) Å, respectively) in comparison to the longest distances between Pd2···Pd5 and Pd3···Pd6 (3.4899(7) and 3.4725(7) Å, respectively). The capping ligands coordinate three Pd atoms in a μ 3 -η 1 :η 1 :η 3 -binding mode, which has been observed in some other transition-metal clusters; a similar μ 2 -η 1 :η 1 :η 3 -binding mode, in which both alkyl bonds are formed with the same metal atom, is known as well. ,, The alkyl bonds feature Pd–C bond lengths from 1.998(4) to 2.015(4) Å, in comparison to Pd–C allyl bond lengths from 2.116(4) to 2.156(4) Å, which agree with literature-reported values for a similar Pd complex featuring the μ 2 :η 1 :η 1 :η 3 binding mode . The μ 3 -η 1 :η 1 :η 3 binding mode of related ligands has so far only been observed as the product of coupling reactions on the metal and has not been derived from cyclopropenium ions …”