Reactivity of the Unsaturated Triosmium Cluster Os3(CO)8(μ3-η2-Ph2PCH2P(Ph)C6H4)(μ-H) with Benzothiophene:  Activation of a P−C Bond in Diphosphine and a C−H Bond in Benzothiophene

• Published in: Organometallics Vol. 24; no. 13; pp. 3315 - 3320
• Main Authors: Kabir, Shariff E, Miah, Md. Arzu, Sarker, Nitai C, Golzar Hussain, G. M, Hardcastle, Kenneth I, Nordlander, Ebbe, Rosenberg, Edward
• Format: Journal Article
• Language: English
• Published: American Chemical Society 20.06.2005
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om050110k

Treatment of the electronically unsaturated cluster Os3(CO)8(μ3-η2-Ph2PCH2P(Ph)C6H4)(μ-H) (1) with benzothiophene in refluxing m-xylene afforded Os3(CO)7(μ-PPh2)(μ-PMePh)(μ3-η2-C6H4) (2), Os3(CO)7(μ3-η2-PPh(C6H4)CH2PPh)(μ3-η3-SC8H5)(μ-H) (3), and Os3(CO)8(μ-CO)(μ3-η2-PPh(C6H4)CH2PPh) (4). Thermolysis of 1 in refluxing toluene for 35 h afforded only 4, whereas in refluxing m-xylene it gave both 4 and 2. Compound 4 can also be obtained from the thermolysis of Os3(CO)9(μ3-η2-PPh(C6H4)CH2PPh2)(μ-H) (5) in refluxing toluene. All the complexes have been structurally characterized. Compound 3 contains a unique example of a μ3-η2 benzothienyl ligand coordinated through the sulfur atom and the C−C double bond of the five-membered ring in a σ,π vinyl fashion. This coordination mode results in the rupture of one osmium−osmium bond, whereas the basic triangular metal framework is retained in the case of 2 and 4, which are derived from the activation of P−C and C−H bonds of 1 and do not contain any benzothiophene-derived ligand.