Experimental and theoretical Mössbauer study of an extended family of [Fe8(µ4-O)4(µ-4-R-px)12X4] clusters.
Experimental and theoretical Mössbauer study of an extended family of [Fe8(µ4-O)4(µ-4-R-px)12X4] clusters.
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[Fe8(µ4-O)4(µ-4-R-px)12X4] 团簇大家族的实验和理论穆斯堡尔研究。
DOI：
10.1021/ic101691q
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发表时间：
2011
影响因子：
4.6
通讯作者：
Zueva EM
中科院分区：
文献类型：
--
作者：
Zueva EM
用穆斯堡尔谱研究了六个含有相同Fe_8（μ_4-O）_4核的[Fe_8（μ_4-O）_4（μ-4-R-pyrazolato）_（12）X_4]配合物的结构。在每种情况下，一个内部的μ4-O桥FeIIIcubane核心被四个三角双锥铁中心包围，两个不同的网站发生在1：1的比例。每个团簇的钼穆斯堡尔谱由两个四极偶极子组成，除了一个例外（X = NCS，R = H），它们重叠在一起，产生三条吸收线。X和R的系统变化导致穆斯堡尔谱发生显着变化。使用密度泛函理论计算的相同的集群的值的比较，使我们能够建立一个明确的分配这些峰的重叠双峰的嵌套模型。单电子还原物种[Fe 8（μ4-O）4（μ-4-Cl-pyrazolato）12 Cl 4]−的Mo穆斯堡尔参数变化（实验和计算）与立方烷核内的氧化还原事件一致。
Six [Fe8(μ4-O)4(μ-4-R-pyrazolato)12X4] complexes containing an identical Fe8(μ4-O)4core have been structurally characterized and studied by Mössbauer spectroscopy. In each case, an inner μ4-O bridged FeIIIcubane core is surrounded by four trigonal bipyramidal iron centers, the two distinct sites occurring in a 1:1 ratio. The Mössbauer spectrum of each of the clusters consists of two quadrupole doublets, which, with one exception (X = NCS, R = H), overlap to give three absorption lines. The systematic variation of X and R causes significant changes in the Mössbauer spectra. A comparison with values for the same clusters computed using density functional theory allows us to establish an unequivocal assignment of these peaks in terms of a nested model for the overlapping doublets. The changes in Mössbauer parameters (both experimental and computed) for the 1-electron reduced species [Fe8(μ4-O)4(μ-4-Cl-pyrazolato)12Cl4]−are consistent with a redox event that is localized within the cubane core.