Benzenethiolato decacarbonyl-p-hydrido-triosmium

Dedecarbonyltriosmium is commercially available (Strem) or may be prepared according to a procedure appearing in these volumes.10 

A 200-mL two-necked round-bottomed flask is fitted with a reflux condenser connected to a nitrogen bubbler. The flask is charged with 0.36 g (0.40 mmol) of dodecacarbonyltriosmium and 100 mL of octane. Under nitrogen 0.073 mL (0.70 mmol) of thiophenol is added and the mixture is heated to reflux with stirring for 3 h. The mixture is then cooled and the solvent is evaporated in vacuo. The yellow residue is dissolved in 15 mL hexane (or heptane) and chromatographed on neutral alumina (Brockman Activity 1,80-200 mesh, Fischer) using hexane or heptane as eluent. A column 12 in. long with a 1-in. diameter is an adequate size. The analytically pure sample can be obtained by recrystallization from hexane. Yield 0.27-0.29 g (70-76%), mp 131 °C. 

Compound 1 is an air-stable, yellow, crystalline solid. It is readily soluble in organic solvents such as hexane, benzene, and dichloromethane. Solutions of 1 in these solvents are stable in air for several weeks. The IR spectrum of 1 contains the following CO absorptions (hexane) 2109(w), 2068 (s), 2059 (m), 2024 (vs), 2018 (m), 2002 (m), 1990 (w), and 1985 (w) cm 1. The NMR spectrum (CDC13) shows a singlet at —17.0 ppm due to the hydride ligand and a multiplet at 7.26 ppm due to the phenyl ring. 

Chemical Properties. When subjected to UV irradiation5 or temperatures 150°C,7 compound 1 eliminates 1 mol of benzene and is transformed into a variety of new thioosmium carbonyl cluster compounds. 

A 500-mL two-necked round-bottomed Pyrex flask is fitted with a gas dispersion tube and a reflux condenser connected to a bubbler. The flask is charged with 0.191 g (0.20mmol) of (/z-benzenethiolato)-decarbonyl- -hydrido-triosmium and 250 mL of cyclohexane. The solution is purged with carbon monoxide (flow rate 50 mL min 1) for 15 min. Then the flow rate is increased to 100 mL min -1 and the solution is irradiated for 2.0 to 2.5 h by using an external high-pressure mercury lamp (e.g., Philips HPK 125 W). The lamp should be maintained at least 12 in. from the reaction flask to minimize heating of the solution. Heating decreases the yield of 2. 

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