New Members of a Class of Iron-Thiolate-Nitrosyl Compounds: Trinuclear Iron-Thiolate-Nitrosyl Complexes Containing Fe3S6 Core
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- 作者：I-Jui Hsu ; Chung-Hung Hsieh ; Shyue-Chu Ke ; Kuo-An Chiang ; Jenn-Min Lee ; Jin-Ming Chen ; Ling-Yun Jang ; Gene-Hsiang Lee ; Yu Wang ; and ; Wen-Feng Liaw
- 刊名：Journal of the American Chemical Society
- 出版年：2007
- 出版时间：February 7, 2007
- 年：2007
- 卷：129
- 期：5
- 页码：1151 - 1159
- 全文大小：353K
- 年卷期：v.129,no.5(February 7, 2007)
- ISSN：1520-5126
文摘
The neutral trinuclear iron-thiolate-nitrosyl, [(ON)Fe(
-S,S-C6H4)]3 (1), and its oxidation product,[(ON)Fe(-S,S-C6H4)]3[PF6] (2), were synthesized and characterized by IR, X-ray diffraction, X-ray absorption,electron paramagnetic resonance (EPR), and magnetic measurement. The five-coordinated, squarepyramidal geometry around each iron atom in complex 1 remains intact when complex 1 is oxidized toyield complex 2. Magnetic measurements and EPR results show that there is only one unpaired electronin complex 1 (Stotal = 1/2) and no unpaired electron (Stotal = 0) in 2. The detailed geometric comparisonsbetween complexes 1 and 2 provide understanding of the role that the unpaired electron plays in the chemicalbonding of this trinuclear complex. Significant shortening of the Fe-Fe, Fe-N, and Fe-S distances aroundFe(1) is observed when complex 1 is oxidized to 2. This result implicates that the removal of the unpairedelectron does induce the strengthening of the Fe-Fe, Fe-N, and Fe-S bonds in the Fe(1) fragment. Asignificant shift of the 
NO stretching frequency from 1751 cm-1 (1) to 1821, 1857 cm-1 (2) (KBr) also indicatesthe strengthening of the N-O bonds in complex 2. The EPR, X-ray absorption, magnetic measurements,and molecular orbital calculations lead to the conclusion that the unpaired electron in complex 1 is mainlyallocated in the Fe(1) fragment and is best described as {Fe(1)NO}7, so that the unpaired electron isdelocalized between Fe and NO via d-
* orbital interaction; some contributions from [Fe(2)NO] and[Fe(3)NO] as well as the thiolates associated with Fe (1) are also realized. According to MO calculations,the spin density of complex 1 is predominately located at the Fe atoms with 0.60, -0.15, and 0.25 atFe(1), Fe(2), and Fe(3), respectively.
-S,S-C6H4)]3 (1), and its oxidation product,[(ON)Fe(-S,S-C6H4)]3[PF6] (2), were synthesized and characterized by IR, X-ray diffraction, X-ray absorption,electron paramagnetic resonance (EPR), and magnetic measurement. The five-coordinated, squarepyramidal geometry around each iron atom in complex 1 remains intact when complex 1 is oxidized toyield complex 2. Magnetic measurements and EPR results show that there is only one unpaired electronin complex 1 (Stotal = 1/2) and no unpaired electron (Stotal = 0) in 2. The detailed geometric comparisonsbetween complexes 1 and 2 provide understanding of the role that the unpaired electron plays in the chemicalbonding of this trinuclear complex. Significant shortening of the Fe-Fe, Fe-N, and Fe-S distances aroundFe(1) is observed when complex 1 is oxidized to 2. This result implicates that the removal of the unpairedelectron does induce the strengthening of the Fe-Fe, Fe-N, and Fe-S bonds in the Fe(1) fragment. Asignificant shift of the NO stretching frequency from 1751 cm-1 (1) to 1821, 1857 cm-1 (2) (KBr) also indicatesthe strengthening of the N-O bonds in complex 2. The EPR, X-ray absorption, magnetic measurements,and molecular orbital calculations lead to the conclusion that the unpaired electron in complex 1 is mainlyallocated in the Fe(1) fragment and is best described as {Fe(1)NO}7, so that the unpaired electron isdelocalized between Fe and NO via d-* orbital interaction; some contributions from [Fe(2)NO] and[Fe(3)NO] as well as the thiolates associated with Fe (1) are also realized. According to MO calculations,the spin density of complex 1 is predominately located at the Fe atoms with 0.60, -0.15, and 0.25 atFe(1), Fe(2), and Fe(3), respectively.