Reaction of ruthenium and iron alkynyl complexes with [Mo2(CO)4(η-C5H5)2] ‡

Photochemical route to unusual tri-tungsten ferrocenylacetylene cluster [W3{μ-η2,η2- (H)CCFc}2(CO)12] and a dimetallacyclodecatetraene [W2{μ-η2,η2,η2,η2- (Fc)CC(H)C(H)C(Fc)C(Fc)C(H)C(H)C(Fc)}(CO)6]

“…The average W-W bond distance (3.1 Å ) is longer than that of W-W bond in [W 2 (OPr i ) 6 (py)(l-C 2 H 2 )] (2.567(1) Å ) [11], [W 2 (g-C 5 H 4 Pr i ) 2 Cl 2 (l-NPh)(l-C 2 Et 2 )] (2.5923(5) Å ) [12], [W 2 (g-C 5 H 4 Pr i ) 2 Cl 3 (PMe 3 )(l-Cl)(l-C 2 Et 2 )] (2.814 (2) Å ) [12], [W 2 (l-PhC 2 AuPPh 3 )(CO) 4 (g-C 5 H 5 ) 2 ] (2.958 (1) Å ) [13] and [Cp * W 2 Fe 2 (CO) 6 (O) 2 (l-O)(l 3 -S) 2 (g 2 -CC(Me)C@CH 2 )] (2.8535(7) Å ) [14], but comparable to that in complex [Cp 2 W 2 Os(CO) 7 (C 2 Tol 2 )] (3.087 Å (av)) [15]. The acetylenic C-C distances of the coordinated ferrocenylacetylene (1.33 Å ) are consistent with the type of bonding present and observed in related molecules: [Pt 3 {l 2 (g 2 -PhC 2 Ph) 2 (Et 3 P) 4 ] (1.34(3) Å ) [11], [Mo 2 (l-g 2 -HC 2 Ph) (CO) 4 (g-C 5 H 5 ) 2 ] (1.354(5) Å ) [16], [Co 2 (CO) 4 (lg 2 -PPh 2 C"CSiMe 3 )(dppm)] (1.344(9) Å ) [17], [W 2 (g-C 5 H 4 Pr i ) 2 Cl 3 (PMe 3 )(l-Cl)(l-C 2 Et 2 )] (2.814(2) Å ) [12], [W 2 (g-C 5 H 4 Pr i ) 2 Cl 2 (l-NPh)(l-C 2 Et 2 )] (1.36(1) Å ) [12] and [W 2 (OPr i ) 6 (py)(l-C 2 H 2 )] (1.39(2) Å ) [11]. Electron counting rules are satisfied if one assumes that the two W-W bonds are of donor-acceptor type.…”

Reactions of metalloalkynes. New C2 bonding mode in a trimetallic complexElectronic supplementary information (ESI) available: Synthesis and characterisation of complexes 4a and 4b. See http://www.rsc.org/suppdata/cc/b1/b110930h/This paper constitutes Part 4 of the series.

“…In this and previous work we have shown that the carbide ligand is able to adopt a diversity of bonding modes depending on the environment in which it finds itself and in the present case we have found a new M 3 (C 2 ) mode which does not contain metal-metal bonds. This work and others involving the C 2 22 dianion has shown it to be relatively labile, with the multimetallic complexes containing this ligand presumably adopting solid state structures influenced by crystal-packing forces.…”

“…which contain the C 2 22 ligand surrounded by ruthenium atoms; these complexes do not contain metal-metal bonds and were characterised by single crystal X-ray studies; the solid state structure is not retained in solution, where it is found to be fluxional on the NMR timescale and the dynamic process postulated could be described as 'bearing-like'.…”

“…The chemistry of even and odd numbered carbon bridges 1-3 is of interest as a matter of scientific curiosity coupled with potential application as molecular wires [4][5][6][7][8][9][10][11][12][13][14][15] and in a number of important materials related fields. [16][17][18][19] One subset of that series, containing the C 2 22 ligand, [20][21][22][23][24] has presented a number of different bonding modes [25][26][27] for M n C 2 (n = 2, 3, 4 and 5). However, to the best of our knowledge the only known example for n = 3 25 contains metal-metal bonds.…”

Reaction of Ruthenium Ethyne‐1,2‐diyl Compounds with Bis(trimethylsilyl)acetylene Complexes of Titanocene and Zirconocene: Remarkable Transfer of a C2 Ligand

“…We, in turn, have been interested in the use of substrates reactive to sites of unsaturation as building blocks for the rational preparation of larger molecules from ruthenium ethyne‐1,2‐diyl compounds,8–16 and viewed complexes 1 and 2 6 as excellent candidates for this purpose. Both complexes contain a ligand that stabilizes the reactive metal center, but which is easily removed to allow access to the reactivity of the unsaturated metal.…”