557791-60-3Relevant academic research and scientific papers
Alkynyl-linked poly(cobaltacarboranes). Directed synthesis, structures, and electrochemistry of linear complexes and benzene-centered pinwheels
Yao, Haijun,Sabat, Michal,Grimes, Russell N.,Zanello, Piero,Fabrizi de Biani, Fabrizia
, p. 2581 - 2593 (2003)
A series of B(5)- and B(7)-alkynyl-substituted derivatives of CoC2B3, CoC2B4, and Co2C2B3 cobaltacarboranes has been prepared and linked via metal-promoted cross-coupling reactions to generate several types of polynuclear molecular complexes, which were structurally characterized and studied via electrochemical techniques. The target compounds prepared include linear dicobalt species containing BC≡CC≡CB linkages, e.g., [Cp*Co(2,3-Et2C2B4H3-7- C≡C)]2 (8) and [Cp*Co(2,3-Et2C2 B4H3-5-C≡C)]2 (17), trigonally symmetrical 1,3,5-triethynylbenzene-anchored tricobalt and hexacobalt complexes, e.g., {Cp*Co(2,3-Et2C2B4H3-5- C≡C)}3C6H3 (19), {Cp*Co(2,3-Et2C2B4H3-7- C≡C)}3C6H3 (22), and 1,3,5-[Cp*2Co2(2,3-Et2C2 B3H2-5-C≡C)]3C6H3 (21), and novel cobaltacarborane-Co2C2 mixed-cluster systems, e.g., Cp*Co(2,3-Et2C2B4 H3)-7-C2HCo2(CO)6 (5) and {Cp*Co[2,3-Et2C2B4H3-7- (C2Co2CO)6]}3C6 H3 (23), a nanocobalt complex. The new compounds were obtained in all cases as air-stable crystalline solids and were characterized by multinuclear NMR and mass spectra, supplemented by X-ray diffraction data for 8, 19, and 21. Electrochemical data on the alkynyl-linked compounds indicate that metal-metal communication in oxidized and reduced species occurs to a limited extent in most cases and to a considerable degree (Robin-Day class III) in the C2B3-bridged triple-decker systems.
