Bimetallic Osmium−Tin Clusters:  Addition of Triphenyltinhydride to Unsaturated [Os₃(CO)₈{μ₃-Ph₂PCH₂P(Ph)C₆H₄}(μ-H)] and Saturated [Os₃(CO)₁₀(μ-dppm)]

Abstract

Reaction of electron-deficient [Os3(CO)8{μ3-Ph2PCH2P(Ph)C6H4}(μ-H)] (2) with Ph3SnH at ambient temperature yields the bimetallic osmium−tin dihydride complexes [Os3(CO)8{μ3-Ph2PCH2P(Ph)C6H4}(SnPh3)(μ-H)2] (3) and [Os3(CO)8(μ-dppm)(SnPh3)2(μ-H)2] (4) via oxidative-addition of one and two Sn−H bonds, respectively, the latter having SnPh3 ligands bound to adjacent osmium atoms. Cluster 3 converts to 4 via oxidative-addition of a further Sn−H bond followed by reductive-elimination of the orthometalated diphosphine. Heating 4 at 128 °C affords isomeric 5, in which both the SnPh3 ligands are bound to the same metal atom, and 5 is also formed from 2 and excess Ph3SnH at 128 °C. Reaction of [Os3(CO)10(μ-dppm)] (1), the saturated counterpart of 2, with Ph3SnH at 110 °C affords [Os3(CO)9(μ-dppm)(SnPh3)(μ-H)] (6), via oxidative-addition of one Sn−H bond, and this converts to 3 upon further heating via loss of one CO followed by orthometallation of the diphosphine. Treatment of 3 with hydrogen (1 atm) at 110 °C gives both the unsaturated dihydride [Os3(CO)7{μ3-Ph2PCH2P(Ph)C6H4}(SnPh3)(μ-H)2] (7) and the electron-precise trihydride [Os3(CO)8(μ-dppm)(SnPh3)(μ-H)3] (8). Thermolysis of 8 at 110 °C gives 7, while heating 3 in refluxing octane yields, after recrystallization from dichloromethane, the unsaturated cluster [Os3(CO)7{μ3-Ph2PCH2P(Ph)C6H4}(SnPh2Cl)(μ-H)2] (9), whereby the coordinated SnPh3 is transformed into a SnPh2Cl group probably via Sn−Ph bond cleavage and chloride addition to the resulting μ-SnPh2 group. The crystal structures of six of these new osmium−tin clusters have been carried out, allowing a detailed analysis of the relative orientations of metal atoms.

Synthesis of new heterometallic complexes by tin–sulfur bond cleavage of pySSnPh3 (pySH = pyridine-2-thiol) at triruthenium and triosmium centres

“…The most widely used method is the oxidative-addition of organotin hydrides and using this methodology a number of transition metal-tin clusters with intriguing structural features have been synthesized, as exemplified by the work of Adams and co-workers [15][16][17][18][19][20][21][22][23][24][25][26]. More recently other tin-element oxidative-addition reactions have been exploited, for example Gárate-Morales and Fernández-G have prepared amine-containing osmium-tin compounds via the cleavage of the nitrogen-tin bond in aminostannanes [27][28][29].…”

Reactions of Ru3(CO)10(μ-dppm) with Ph3GeH: Ge–H and Ge–C bond cleavage in Ph3GeH at triruthenium clusters

“…The stability of 2 in refluxing THF was also examined as it would allow us to compare the product distribution vis-à-vis the thermolysis reaction of 1, which furnishes 3 via cleavage of the Ge-C and Ru-Ru bonds and gives 4 via activation of the P-C and C-H bonds of the dppm ligand. Thermolysis of 2 affords the dinuclear complex 3 as the major product (31%) and the hydroxyl-bridged dihydride cluster Ru3(CO)6(GePh3)(µ-OH)(µ-dppm)(µ-H)2 (6) in 16% yield as the minor product. The reaction is illustrated in Scheme 4.…”

“…The resulting heterogeneous nanoparticle catalysts may be prepared by the deposition of a metal cluster containing a Group 14 ligand on an oxide support, yielding systems that exhibit high activity and selectivity for certain types of hydrogenation and dehydrogenation reactions [4]. We have been investigating the synthesis and structure of metal carbonyl complexes containing organogermanium and organotin ligands that can be used as precursors in the synthesis of such nanoscale catalysts during the last few years [5][6][7][8]. Ruthenium combined with the Group 14 elements, such as germanium or tin, continues to dominate the attention of different research groups with interest in catalysis [9][10][11].…”

“…Studies have shown that the incorporation of organogermanium/organotin moieties into the coordination sphere of a metal carbonyl cluster by oxidative addition of the corresponding hydrides R3EH (where E = Ge, Sn; R = alkyl, aryl) remains a convenient and widely used method for the synthesis of new Group 14-substituted metal clusters [6,7,[21][22][23][24]. Recently, we reported the preparation of new Os3Snx and Os3Gex clusters from the reactions of Os3(CO)10(μ-dppm) and the related ligand-activated cluster Os3(CO)8[μ3-Ph2PCH2P(Ph)C6H4](μ-H)with Ph3SnH [6] and Ph3GeH [7].…”

“…Studies have shown that the incorporation of organogermanium/organotin moieties into the coordination sphere of a metal carbonyl cluster by oxidative addition of the corresponding hydrides R3EH (where E = Ge, Sn; R = alkyl, aryl) remains a convenient and widely used method for the synthesis of new Group 14-substituted metal clusters [6,7,[21][22][23][24]. Recently, we reported the preparation of new Os3Snx and Os3Gex clusters from the reactions of Os3(CO)10(μ-dppm) and the related ligand-activated cluster Os3(CO)8[μ3-Ph2PCH2P(Ph)C6H4](μ-H)with Ph3SnH [6] and Ph3GeH [7]. This work reinforces the view that cluster degradation, which is frequently observed during the reaction between metal carbonyl clusters and organotin/organogermanium hydrides or other tin/germanium sources, may be significantly inhibited by the presence of a bridging dppm ligand that can impart additional stabilization to the metallic polyhedron by the ability to hold contiguous metal centers together.…”