The Molecular Configuration of Dicobalt Hexacarbonyl Diphenylacetylene

Chemistry and synthetic utility of cobalt-complexed propargyl cations

Molecular Rods. 1. Simple Axial Rods.

https://science.sciencemag.org/content/sci/196/4292/839.full.pdf

Molecular metal clusters.

Publisher Summary This chapter discusses the development of metal carbonyl chemistry. Solutions of octacarbonyldicobalt in hydrocarbon solvents can be prepared by a high–pressure reaction between a cobalt compound, such as cobalt carbonate, and a mixture of carbon monoxide and hydrogen. Solutions of octacarbonyldicobalt in petroleum solvents react readily at room temperature with a large variety of alkynes to give complexes of general formula Co2(CO)6(RC2R´). Octacarbonyldicobalt decomposes readily at about 50°–60°C to give dodecacarbonyltetracobalt, and this thermal degradation reaction provides a convenient synthesis of Co4(CO)12 on a small scale. The rate of exchange of carbon monoxide with several other CO2(CO)6(RC2R´) complexes in hexane is investigated. The mercury carbonylcobalt compound Hg[Co(CO)4]2 is obtained by the treatment of the anion [Co(CO)4]– with mercury salts, such as Hg(CN)2 and by the treatment of Co2(CO)8 with Na/Hg. Hg[Co(CO)4]2 is obtained as orange air-stable crystals of m.p. 81°–82°C. The infrared spectrum of the solutions of the compound in CS2 show vco at 2028 and 1967 cm–l, and the nuclear magnetic resonance (NMR) spectrum of the CS2 solution shows the cyclopentadienyl proton resonance as a sharp singlet at δ 5.00. The unsymmetrical isomer 2,4–bis(pentafluorophenyl)–3,5–diphenylcyclopentadienone–n–cyclopentadienylcobalt is the only product isolated from the reaction of (π–C5H5)CO(CO)2 and C6H5C=CC6F5. The involvement of metalocyclopentadiene intermediates in the cyclotrimerization of alkynes has been established for some metal systems.

Compounds Derived from Alkynes and Carbonyl Complexes of Cobalt

Durch Einwirkung von Acetylenderivaten auf Kobaltcarbonyle konnten neue Organo-Kobaltcarbonyl-Komplexe vom Typ Co4(CO)10(R.C2.R′), Co2(CO)4(R.C2.R′)3, Co2(CO)6(R.C2H)3, Co2Hg(CO)6(R.C2H)4, Co2(CO)6(R.C2H)4, Co(CO)3X(R.C2H)2 und Co2nHgn(CO)4n + 4(R.C2H)2n–2 dargestellt werden, deren Strukturen sich durch Abbaureaktionen weitgehend aufklaren liesen. Die Bildung der einzelnen Komplextypen ist hauptsachlich von der Art der Alkin-Komponente abhangig. Die meisten der verwendeten Alkine werden unter den Bedingungen der Komplexdarstellung gleichzeitig zu unsymmetrischen Benzolderivaten trimerisiert. Eine exakte Aufklarung des Trimerisierungsmechanismus war nicht moglich. Das Gesamtbild der Reaktionen scheint jedoch zu bestatigen, das Organo-Kobaltcarbonyle als Trager der katalytischen Wirksamkeit anzusehen sind.

The Molecular Configuration of Dicobalt Hexacarbonyl Diphenylacetylene

Citations

Chemistry and synthetic utility of cobalt-complexed propargyl cations

Molecular Rods. 1. Simple Axial Rods.

Molecular metal clusters.

Compounds Derived from Alkynes and Carbonyl Complexes of Cobalt

Über Organometall‐Komplexe, VIII. Reaktionen von Kobaltcarbonyl‐Verbindungen mit Alkinen

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