Tetrabutylammonium Tetracyanocobaltate(II) Dioxygen Carriers

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• 作者：Ingrid K. Meier ; Ronald M. Pearlstein ; Dorai Ramprasad ; and Guido P. Pez
• 刊名：Inorganic Chemistry
• 出版年：1997
• 出版时间：April 9, 1997
• 年：1997
• 卷：36
• 期：8
• 页码：1707 - 1714
• 全文大小：190K
• 年卷期：v.36,no.8(April 9, 1997)
• ISSN：1520-510X

文摘

The second example of a low-spin, square-planarCo(II)L₄ species (L = unidentate ligand),(Bu₄N)₂Co(CN)₄(1),and a new family of tetrabutylammonium tetracyanocobaltate(II)complexes have been isolated and characterized.All of the solid compounds react reversibly with dioxygen to form1:1 cobalt(III)-superoxo complexes. Sincea variety of neutral bases react readily with 1 and thecomplexes can be obtained as solids, the effects ofdifferentaxial bases on the dioxygen-binding behavior of the solids could alsobe studied. Interestingly, reversible phasechanges occur on oxygenation/deoxygenation for(Bu₄N)₂[Co(CN)₄·C₅H₅N](2) and[(Bu₄N)₂Co(CN)₄]₂·(C₁₀H₈N₂)(3). Presumably this happens because the crystallattices of the unoxygenated materials do not containenoughroom for the dioxygen. Complex 2 crystallizes in theorthorhombic space group Pbcm with the followingcellparameters at 25 mages/entities/deg.gif">C: a = 9.024(3) Å,b = 21.886(8) Å, c = 23.184(6) Å,V = 4578.6(27) ų, and Z =4. Fromthe molecular packing, it is apparent that the[Co(CN)₄·C₅H₅N]^2-anions are aligned parallel to the a axis, withthe pyridine of each anionic unit pointing toward the vacant site onthe cobalt of the adjacent anion. Thetetrabutylammonium cations completely surround the anions, forminghydrophobic casings that also run parallelto the a axis. Thus, it is clear that the bulkytetrabutylammonium cations are capable of separating thecobaltcenters so that mages/entities/mgr.gif">-peroxo dimers cannot form.