TCNE Dimer Dianion Coordination Complexes, [Mn(TPA)(TCNE)]2[2-(TCNE)2] and [Mn(TPA)(4-C4(CN)8)0.5]·ClO4, TP

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• 作者：Guangbin Wang ; Carla Slebodnick ; Gordon T. Yee
• 刊名：Inorganic Chemistry
• 出版年：2007
• 出版时间：November 12, 2007
• 年：2007
• 卷：46
• 期：23
• 页码：9641 - 9645
• 全文大小：146K
• 年卷期：v.46,no.23(November 12, 2007)
• ISSN：1520-510X

文摘

The structures and magnetic properties of two products that result from the reactions of [Mn(TPA)(CH₃CN)₂](ClO₄)₂,TPA = tris(2-pyridylmethyl)amine and potassium tetracyanoethylenide, KTCNE, are reported. [Mn(TPA)(TCNE)]₂[₂-(TCNE)₂] (1) and [Mn(TPA)(₄-C₄(CN)₈)_0.5]·ClO₄ (2) are obtained by using two different ratios of the initialreactants. Each was intended to possess two or more cis-TCNE radical anions (TCNE^/-) as ligands. 1 is a dinuclearspecies that crystallizes in the triclinic system in the space group P, with a = 10.4432(17), b = 12.2726(16), andc = 13.708(2) Å; = 88.505(12), = 75.560(14), and = 87.077(12); V = 1698.9(4) ų; and Z = 1 andfeatures two metal centers each with three nearly orthogonal TCNE^/- ligands. However, the three TCNE^/- ligandsare all dimerized via the formation of four-center, two-electron bonds: two bridge the two Mn(II) centers, and athird TCNE^/- ligand forms an intermolecular bond to another equivalent TCNE^/-. 2 crystallizes in the tetragonalsystem in the space group P4₂2₁2, with a = 17.170(3), b = 17.170(3), and c = 17.1837(6) Å; V = 5065.9(13)ų; and Z = 8. It consists of a ribbon-like coordination polymer containing the previously observed but still relativelyrare octacyanobutyl dianion. The [C₄(CN)₈]^2- anion is derived from the dimerization of two TCNE radical anions viathe formation of a new bond, and each anion bridges four Mn(II) centers. Both 1 and 2 display magnetic behaviorconsistent with only weak antiferromagnetic coupling between the high-spin d⁵ Mn(II) in which the TCNE^/- arerendered diamagnetic through dimerization.