Structural characterization of [Fe(NO)(mnt)2]1-/2- salts
Structural characterization of [Fe(NO)(mnt)2]1-/2- salts
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DOI：
10.1016/j.poly.2011.09.001
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发表时间：
2012-01-04
期刊：
影响因子：
2.6
通讯作者：
Donahue, James P.
中科院分区：
文献类型：
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作者：
Jayarathne, Upul;Williams, Kia;Donahue, James P.
二硫烯铁化合物 [Fe-2(mnt)(4)](2-) [1](2-) 和 [Fe(NO)(mnt)(2)](n) (n = 1-, [2](1-); n = 2-. [2](2-)) ([mnt](2-) = 马来酸二硫醇 = [(NC)(2)C2S2](2-)) 的结构特征如下其 [Et4N](+) 盐在 100 K 下进行 X 射线衍射。二价阴离子 [2](2-) 是通过用 Na[Et3BH] 还原从 [2](1-) 制备的，观察到其在 149.9(5) 度处具有弯曲的 Fe-N=O 角，这与 [2](1-) (180.0 度) 中 Fe-N=O 的线性构型形成鲜明对比。 NO 从线性结合模式变为弯曲结合模式、Fe-N 键长增加超过 01 埃，以及 [2](2-) 与 [2](1-) 的 Fe-S 距离相对不变，表明 NO 配体是还原位点。 [2](1-)的[Et3NH](+)络合物也通过晶体学鉴定，并发现[Et3NH](+)和[mnt](2-)配体的氰基氮原子之间存在氢键接触。此外，[2](1-) 阴离子之间存在相对紧密的 S...S 接触（3.602-3.615 埃），它们以偏移、头对头的方式堆积在一起。 [Et4N][2] 结构中不存在这些 S...S 接触。红外光谱显示 [2](2-) 中 N=O 键拉伸吸收峰的能量降低且显着变宽，这与弯曲的 NO 配体通过围绕 Fe-N 轴轻松旋转和通过 Fe-N=O 角度的呼吸采样一系列构象是一致的。 (C) 2011 Elsevier Ltd. 保留所有权利。
The iron dithiolene compounds [Fe-2(mnt)(4)](2-) [1](2-) and [Fe(NO)(mnt)(2)](n) (n = 1-, [2](1-); n = 2-. [2](2-)) ([mnt](2-) = maleonitriledithiolate = [(NC)(2)C2S2](2-)) have been characterized structurally by X-ray diffraction as their [Et4N](+) salts at 100 K. Dianion [2](2-) is prepared from [2](1-) by reduction with Na[Et3BH] and is observed to have a bent Fe-N=O angle at 149.9(5)degrees in contrast to the linear configuration of Fe-N=O in [2](1-) (180.0 degrees). The change from linear to bent binding mode for NO, an increase of more than 01 angstrom in the Fe-N bond length, and the relative invariance of the Fe-S distances for [2](2-) versus [2](1-) indicate that the NO ligand is the site of reduction. The [Et3NH](+) complex of [2](1-) was also identified by crystallography and found to have hydrogen bonding contacts between [Et3NH](+) and the cyano nitrogen atom of an [mnt](2-) ligand. Furthermore, relatively close S...S contacts (3.602-3.615 angstrom) occur between [2](1-) anions, which pack together in an offset, head-to-head fashion. These S...S contacts are absent in the structure of [Et4N][2]. Infrared spectra show an energy decrease for, and a significant broadening of, the N=O bond stretching absorption peak in [2](2-), which is consistent with a bent NO ligand sampling a range of conformations both by facile pivoting about the Fe-N axis and by a breathing of the Fe-N=O angle. (C) 2011 Elsevier Ltd. All rights reserved.