Structural and Spectroscopic Trends in a Series of Half-Sandwich Scorpionate Complexes

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• 作者：Shengwen Liang ; Haoshuang Wang ; Tapash Deb ; Jeffrey L. Petersen ; Gordon T. Yee ; Michael P. Jensen
• 刊名：Inorganic Chemistry
• 出版年：2012
• 出版时间：December 3, 2012
• 年：2012
• 卷：51
• 期：23
• 页码：12707-12719
• 全文大小：550K
• 年卷期：v.51,no.23(December 3, 2012)
• ISSN：1520-510X

文摘

Fifteen half-sandwich scorpionate complexes [(L)M(NCMe)₃](BF₄)_n (L = tris(3,5-dimethylpyrazol-1-yl)methane, Tpm^Me,Me, n = 2, 1^M, M = Mn, Fe, Co, Ni; L = tris(3-phenylpyrazol-1-yl)methane, Tpm^Ph, n = 2, 2^M, M = Mn, Fe, Co, Ni; L = hydrotris(3,5-dimethylpyrazol-1-yl)borate, [Tp^Me,Me]^{鈭?/sup>, n = 1, 3M, M = Fe, Co, Ni; L = hydrotris(3-phenyl-5-methylpyrazol-1-yl)borate, [TpPh,Me]鈭?/sup>, n = 1, 4M, M = Mn, Fe, Co, Ni) were prepared by addition of the tripodal ligands to solvated [M(NCMe)_x]2+ (M = Mn, x = 4; M = Fe, Co, Ni, x = 6) precursor complexes. The product complexes were characterized by 1H NMR (except M = Mn), UV鈥搗is鈥揘IR, and FTIR spectroscopy. The structures of 2Mn, 2Ni, 3Fe, 3Co, and 4Fe were determined by X-ray crystallography. The data were consistent with complexes of high-spin divalent metal ions in idealized piano-stool geometries in all cases. Consequent lability of the acetonitrile ligands will enable use of these complexes as synthetic precursors and as catalysts. Comparison to previously reported structures of 1Fe, 1Co, 2Fe, and 2Co, the triflate salt analogues of 4Co and 4Ni, as well as related sandwich complexes (e.g., [(TpMe,Me)₂M]) and solvated metal dications [M(NCMe)₆]2+ reveals numerous trends in M鈥揘 bond lengths. Primary among these are the Irving鈥揥illiams series, with significant structural effects also arising from ligand charge and sterics. Systematic trends in spectroscopic data were also observed which further elucidate these issues.}