Sodium tetracarbonylcobaltate

Several mixed-metal clusters containing platinum and cobalt are known and some of them have been employed as methanol homologation catalysts.1 Among them, the title compound2 was first prepared unambiguously from the reaction of dichloro[l,2-ethanediylbis(diphenylphosphine)]platinum with sodium tetracarbonylcobaltate, Na[CO(CO)4]. The compound also may be prepared by the reaction of [l,2-ethanediylbis(diphenyl-phosphine)]bis(phenylethynyl)pIatinum with Co COJg.1... 

Sodium tetracarbonylcobaltate(l —) is prepared from Co2(CO)g (0.6 g) and 3% of Na-Hg (15 g) in tetrahydrofuran (THF).8 Dichloro[l,2-ethanediylbis-(diphenylphosphine)]platinum (1.0 g, 1.5 mmol) is suspended in freshly distilled, dry, and oxygen-free THF (20 mL) in a 100-mL two-necked flask fitted with a refluxing condenser, a Teflon-coated magnetic stirring bar, and an inlet for nitrogen connected to a mercury or mineral oil bubbler for venting excess gases. 

Uninegative cobalt is found in sodium tetracarbonylcobaltate(—I), NaCo(CO)4, which is a typical salt with the anion [ 0(00)4] This and the corresponding salts of potassium and calcium are related to cobalt carbonyl hydride (p, 303). 

It has been deduced from results of preparations of acylcobalt carbonyl complexes using sodium tetracarbonylcobaltate(-l) and alkyl halides (101) that in the reaction of an olefin with HCo(CO)4 and carbon monoxide, an alkylcobalt tetracarbonyl is the precursor of the acylcobalt tetracarbonyl. 

Related Reagents. Dicarbonyl(cyclopentadienyl)cobalt(I) Octacarbonyldicobalt-Diethyl(methyl)silane-Carbon Monoxide Sodium Tetracarbonylcobaltate. 

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