Experimental and Theoretical Mo虉ssbauer Study of an Extended Family of [Fe8(渭4-O)4(渭-4-R-px)12X4] Clusters

详细信息    查看全文

• 作者：Ekaterina M. Zueva ; W. M. C. Sameera ; Dalice M. Pin虄ero ; Indranil Chakraborty ; Eamonn Devlin ; Peter Baran ; Katarina Lebruskova ; Yiannis Sanakis ; John E. McGrady ; Raphael G. Raptis
• 刊名：Inorganic Chemistry
• 出版年：2011
• 出版时间：February 7, 2011
• 年：2011
• 卷：50
• 期：3
• 页码：1021-1029
• 全文大小：980K
• 年卷期：v.50,no.3(February 7, 2011)
• ISSN：1520-510X

文摘

Six [Fe₈(渭₄-O)₄(渭-4-R-pyrazolato)₁₂X₄] complexes containing an identical Fe₈(渭₄-O)₄ core have been structurally characterized and studied by M枚ssbauer spectroscopy. In each case, an inner 渭₄-O bridged Fe^III cubane core is surrounded by four trigonal bipyramidal iron centers, the two distinct sites occurring in a 1:1 ratio. The M枚ssbauer 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 M枚ssbauer 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 M枚ssbauer parameters (both experimental and computed) for the 1-electron reduced species [Fe₈(渭₄-O)₄(渭-4-Cl-pyrazolato)₁₂Cl₄]^{鈭?/sup> are consistent with a redox event that is localized within the cubane core.}