Carborane Complexes of Ruthenium:  Synthesis of the Bimetal Compounds [MRu(μ-CC₆H₄Me-4)(CO)₄(η⁵-7,8-C₂B₉H₁₁){κ³-HB(pz)₃}] (M = Mo or W) and Their Reactions with Sulfur and Selenium^,

Abstract

Addition of the reagent [Ru(CO)2(thf)(η 5-7,8-C2B9H11)] (thf = tetrahydrofuran) to the compounds [M(⋮CC6H4Me-4)(CO)2{κ 3-HB(pz)3}] (M = Mo or W, HB(pz)3 = hydrotris(pyrazol-1-yl)borato) in CH2Cl2 affords, respectively, the bimetal species [MRu(μ-CC6H4Me-4)(CO)4(η 5-7,8-C2B9H11){κ 3-HB(pz)3}] (M = Mo (4a), M = W (4b)). These complexes are readily cleaved by donor molecules, including thf, but they are stable in CH2Cl2 or toluene. X-ray diffraction studies established the molecular structures of 4b and the related species [WRu(μ-CC6H4Me-4)(CO)4(η 5-7,8-C2B9H11)(η 5-C5H5)] (2b). In both molecules very long Ru−W bonds (ca. 3 Å) are asymmetrically bridged by the tolylmethylidyne groups (μ-C−W av 1.92 Å, μ-C−Ru av 2.21 Å). The complexes 4 react with sulfur or selenium in CH2Cl2 to give the compounds [MRu(μ-1κ C α ,1:2κ E-ECC6H4Me-4)(CO)4(η 5-7,8-C2B9H11){κ 3-HB(pz)3}] (M = Mo, E = S (6a), Se (6c); M = W, E = S (6b), Se (6d)). The structure of 6b was established by X-ray diffraction. The molecule possesses an unusual structure in which Ru(CO)2(η 5-7,8-C2B9H11) and W(CO)2{κ 3-HB(pz)3} units are bridged by a thioacyl group which is η 2-coordinated to the tungsten through its carbon and sulfur atoms and bound to the ruthenium only through the sulfur atom. There is no metal−metal bond as both the W and Ru atoms have filled valence shells. The NMR data for the new compounds are reported and discussed.

Thioxoethenylidene (CCS) as a Bridging Ligand

“…19 Binuclear chalcoacyl complexes, however all adopt a dimetallachalcotetrahedrane geometry in which the CE (E = S, Se, Te) group transversely bridges a metal-metal bond (Chart 1), 20 with the exception of [MRu(µ-SCC 6 H 4 Me-4)(CO) 4 (η 5 -C 2 B 9 H 9 Me 2 )(Tp)] (Chart 1e; Tp = hydrotris(pyrazol-1-yl)borate). 21 The spectroscopic data for 3, whilst indicating a binuclear complex of low symetry, did not allow for unequivocal identification, not least because the small range of 13 C NMR data reported for thioacyl groups 18 overlaps somewhat with the wide range observed for alkyidyne ligands (vide infra, Table 1 18,19, [22][23][24][25][26][27][28] ). 17 The formulation was however confirmed by a crystallographic analysis, the results of which are summarised in Figure 1.…”

Designer clusters: synthesis and characterization of Cp*2Rh2Co3(CO)8B3HCl (Cp* =η5-C5Me5)

“…This is consistent with earlier work which demonstrates that BH bonds can interact directly with transition metal centers. [15][16][17][18] For example, the activity of exocluster B-H bonds towards metal addition has been utilized in promoting the addition of unsaturated organic substrates to borane cages. 19 Thus, even though we have no direct evidence for the cluster-Co(CO) 4 intermediates proposed in Scheme 2, their existence is reasonable.…”

Reactions of Cyclic Osmacarbyne with Coinage Metal Complexes

“…The facile and efficient conversion reflects the weak interaction between CuCl and the osmacarbyne. Cleavages of the metal salts from the tungsten or molybdenum carbyne-metal salt adducts have been observed when they were treated with donor ligands, , such as tetrahydrofuran, carbon monoxide, PMe 3 , or sulfur…”

“…The formation of the M–M and M–C bonds in these reactions offer valuable information to understand the principles of catalytic reactions, especially for the multimetallic catalysis . Various metal carbyne complexes, e.g., chromium, molybdenum, , tungsten, − manganese, rhenium, , and osmium carbynes, with a second metal complex have been investigated in the literature. However, most of them are the acyclic metal carbynes, the related chemistry of cyclic metal carbyne complexes has scarcely been reported …”