Dissolving metals thiophenes

The Schlenk flask was charged with [Ir(COD)Cl]2 (9.4 mg) and 1 mL of dry dichloromethane. (45)-tert-butyl-2-(3-diphenylphosphino-thiophene-2-yl)4,5-dihydrooxazole (10 mg) was dissolved in anhydrous dichloromethane (2mL) under an argon atmosphere, and added to the metal precursor. The orange-red solution was heated at reflux for 2 h. 

Another approach to the extraction of DBTs from a simulated petroleum fuel was the use of the water-soluble (NH3)5Ru(H20) +, which is known to bind to thiophene (T) as(NH3)5Ru(T) +. Because DBT binds more strongly than T in other metal complexes, it was expected that DBT would form (NPl3)5Ru( (S)-DBT) +. The complex is thermally stable but is very air-sensitive, requiring manipulations to be conducted with the carefiil exclusion of air. The (NH3)5Ru(H20) + complex dissolved in a solution of 30% H2O and 70% dimethyl formamide was able to extract 50% of the 400 ppm of sulfiu (in the form of DBT) in a 45% toluene/55% hexanes phase. An analogous extraction of 4,6-Mc2DBT was able to remove only 15% of the 4,6-Me2DBT. 

To a dry flask containing 15 ml of absolute ethanol is added 0.46 gm (0.02 gm atom) of sodium metal. After the metal dissolves 1.5 gm (0.01 mole) of hexamethylenedithiol is added. The disodium salt of the dithiol precipitates and is then redissolved when the mixture is heated. To the hot solution is added 25 ml of dry thiophene-ffee benzene followed immediately by 2.15 gm (0.01 mole) of tetramethylene dibromide. An immediate vigorous reaction is initiated and the solvent begins to reflux. When the reaction subsides, another 25 ml of benzene is added and the mixture refluxed overnight. The polymer is isolated by pouring the reaction mixture into methanol. The polymer yield is 1.08 gm (50%) (m.p., 63°-65°C inherent viscosity, 0.36 dl/gm). 

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