Odd-Numbered FeIII Complexes: Synthesis, Molecular Structure, Reactivity, and Magnetic Properties
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- 作者：Ayuk M. Ako ; Oliver Waldmann ; Valeriu Mereacre ; Frederik Klö ; wer ; Ian J. Hewitt ; Christopher E. Anson ; Hans U. Gü ; del ; Annie K. Powell
- 刊名：Inorganic Chemistry
- 出版年：2007
- 出版时间：February 5, 2007
- 年：2007
- 卷：46
- 期：3
- 页码：756 - 766
- 全文大小：482K
- 年卷期：v.46,no.3(February 5, 2007)
- ISSN：1520-510X
文摘
Three isostructural disklike heptanuclear FeIII compounds of the general formula [FeIII7(
ages/entities/mgr.gif">3-O)3(L)3(ages/entities/mgr.gif">-O2CCMe3)6(ages/gifchars/eta.gif" BORDER=0 >1-O2CCMe3)3(H2O)3], where L represents a di- or triethanolamine moiety, display a three-blade propeller topology,with the central Fe atom representing the axle or axis of the propeller. This motif corresponds to the theoreticalmodel of a frustrated Heisenberg star, which is one of the very few solvable models in the area of frustratedquantum-spin systems and can, furthermore, be converted to an octanuclear cage for the case where L istriethanolamine to give [FeIII8(ages/entities/mgr.gif">4O)3(ages/entities/mgr.gif">4-tea)(teaH)3(O2CCMe3)6(N3)3]·1/2MeCN·1/2H2O or [FeIII8(ages/entities/mgr.gif">4O)3(ages/entities/mgr.gif">4-tea)(teaH)3(O2CCMe3)6(SCN)3]·2MeCN when treated with excess NaN3 or NH4SCN, respectively. The core structure is formallyderived from that of the heptanuclear compounds by the replacement of the three aqua ligands by an {Fe(tea)}moiety, so that the 3-fold axis of the propeller is now defined by two central FeIII atoms. Magnetic studies on twoof the heptanulcear compounds established unequivocally S = 5/2 spin ground state for these complexes, consistentwith overall antiferromagnetic interactions between the constituent FeIII ions.