A Bridging Hexazene (RNNNNNNR) Ligand from Reductive Coupling of Azides
摘要:
This communication reports the first examples of transition metal complexes containing an RNNNNNNR(2-) ligand. Addition of 1-azidoadamantane to the diiron(l) synthon L(R)FeNNFeL(R) (L(R) = HC[C(R)N(2,6-iPr(2)C(6)H(3))](2); R methyl, tert-butyl) leads to the diiron complexes L(R)Fe(mu-eta(2):eta(2)-AdN(6)Ad)FeL(R), which are surprisingly thermally stable. Magnetic, Mossbauer, and crystallographic data are consistent with pairs of high-spin iron(II) ions antiferromagnetically coupled through a dianionic AdN(6)Ad(2-) bridge.
Three-Coordinate Terminal Imidoiron(III) Complexes: Structure, Spectroscopy, and Mechanism of Formation
作者:Ryan E. Cowley、Nathan J. DeYonker、Nathan A. Eckert、Thomas R. Cundari、Serena DeBeer、Eckhard Bill、Xavier Ottenwaelder、Christine Flaschenriem、Patrick L. Holland
DOI:10.1021/ic100846b
日期:2010.7.5
azide with iron(I) diketiminate precursors gives metastable but isolable imidoiron(III) complexes LFe═NAd (L = bulky β-diketiminate ligand; Ad = 1-adamantyl). This paper addresses (1) the spectroscopic and structural characterization of the Fe═N multiplebond in these interesting three-coordinate iron imido complexes, and (2) the mechanism through which the imido complexes form. The iron(III) imido
1-金刚烷基叠氮化物与二酮亚胺铁(I)前体的反应产生亚稳但可分离的亚胺铁(III)配合物LFe=NAd(L=庞大的β-二酮亚胺配体;Ad=1-金刚烷基)。本文讨论了 (1) 这些有趣的三配位铁亚胺配合物中 Fe=N 多重键的光谱和结构表征,以及 (2) 亚胺配合物形成的机制。铁 (III) 亚胺配合物已被1H NMR 和电子顺磁共振 (EPR) 光谱和温度相关磁化率 (SQUID),并通过晶体学和/或扩展 X 射线吸收精细结构 (EXAFS) 测量进行结构表征。这些数据表明,酰亚胺配合物具有四重基态和短 (1.68 ± 0.01 Å) 铁氮键。酰亚胺配合物的形成通过未观察到的铁-N 3 R 中间体进行,通过 QM/MM 计算表明,最好将其描述为具有 N 3 R 自由基阴离子的铁 (II) 。有机叠氮化物上的激进特征弯曲了它的 NNN 键以实现简单的 N 2损失和亚氨基复合物的形成。亚胺铁 (III)