Reactivity and Structural and Physical Studies of Tetranuclear Iron(III) Clusters Containing the [Fe4(3-O)2
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- 作者：Theocharis C. Stamatatos ; Athanassios K. Boudalis ; Yiannis Sanakis ; Catherine P. Raptopoulou
- 刊名：Inorganic Chemistry
- 出版年：2006
- 出版时间：September 4, 2006
- 年：2006
- 卷：45
- 期：18
- 页码：7372 - 7381
- 全文大小：310K
- 年卷期：v.45,no.18(September 4, 2006)
- ISSN：1520-510X
文摘
The initial use of di-2-pyridyl ketone oxime [(py)2CNOH] in iron(III) carboxylate chemistry has yielded the tetranuclearcomplex [Fe4O2Cl2(O2CMe)2{(py)2CNO}4] (1). Compound 1 can be synthesized either by the 1:2:1 molar ratioreaction between FeIII, MeCO2-, and (py)2CNOH (complex 1a) or by the 1:3 molar ratio reaction between [Fe3O(O2CMe)6(H2O)3]Cl and (py)2CNOH (complex 1b). The presence of N3- in both reaction mixtures has afforded thetetranuclear complex [Fe4O2(N3)2(O2CMe)2{(py)2CNO}4] (2), which can be alternatively synthesized by the reactionof 1 with N3-. Compound 1a crystallizes in the tetragonal space group I
with (at 25 
C) a = 35.06(2) Å, b =35.06(2) Å, c = 13.255(6) Å, V = 16293(2) Å3, and Z = 8. Compound 1b crystallizes in the monoclinic spacegroup P21/c with (at 25 C) a = 22.577(7) Å, b = 17.078(6) Å, c = 17.394(6) Å, 
= 93.50(1), V = 6694(4) Å3,and Z = 4. Compound 2 crystallizes in the triclinic space group P
with (at 25 C) a = 13.658(9) Å, b = 15.815(9)Å, c = 17.29(1) Å, 
= 97.08(3), = 98.55(3), 
= 112.12(3), V = 3355(4) Å3, and Z = 2. The structuresof 1 and 2 contain the [Fe4(
3-O)2]8+ core comprising four FeIII ions in a "butterfly" disposition and two 3-O2- ions,each bridging three FeIII ions forming the "wings" of the "butterfly". The Mössbauer spectra of 1b and 2 consist ofcomposite quadrupole-split doublets, with parameters typical for high-spin FeIII in octahedral environments. Magneticsusceptibility measurements on 1a revealed antiferromagnetic interactions between the S = 5/2 ferric ions, withbest-fit parameters being Jwb = -40.2 cm-1 and Jbb = -59.4 cm-1 (H = -2
JiJj) for wingtip-body and body-body interactions, respectively, yielding an S = 1 ground state. Both wingtip-body and body-body interactions arewell determined.
with (at 25 C) a = 35.06(2) Å, b =35.06(2) Å, c = 13.255(6) Å, V = 16293(2) Å3, and Z = 8. Compound 1b crystallizes in the monoclinic spacegroup P21/c with (at 25 C) a = 22.577(7) Å, b = 17.078(6) Å, c = 17.394(6) Å, = 93.50(1), V = 6694(4) Å3,and Z = 4. Compound 2 crystallizes in the triclinic space group P with (at 25 C) a = 13.658(9) Å, b = 15.815(9)Å, c = 17.29(1) Å, = 97.08(3), = 98.55(3), = 112.12(3), V = 3355(4) Å3, and Z = 2. The structuresof 1 and 2 contain the [Fe4(3-O)2]8+ core comprising four FeIII ions in a "butterfly" disposition and two 3-O2- ions,each bridging three FeIII ions forming the "wings" of the "butterfly". The Mössbauer spectra of 1b and 2 consist ofcomposite quadrupole-split doublets, with parameters typical for high-spin FeIII in octahedral environments. Magneticsusceptibility measurements on 1a revealed antiferromagnetic interactions between the S = 5/2 ferric ions, withbest-fit parameters being Jwb = -40.2 cm-1 and Jbb = -59.4 cm-1 (H = -2JiJj) for wingtip-body and body-body interactions, respectively, yielding an S = 1 ground state. Both wingtip-body and body-body interactions arewell determined.