Dinuclear and Hexanuclear Iron(III) Oxide Complexes with a Bis(bipyridine) Ligand: A New [Fe6(3-O)4]<
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- 作者：Craig M. Grant ; Michael J. Knapp ; William E. Streib ; John C. Huffman ; David N. Hendrickson ; and George Christou
- 刊名：Inorganic Chemistry
- 出版年：1998
- 出版时间：November 16, 1998
- 年：1998
- 卷：37
- 期：23
- 页码：6065 - 6070
- 全文大小：234K
- 年卷期：v.37,no.23(November 16, 1998)
- ISSN：1520-510X
文摘
The use of the bis(bipyridine) ligand L (1,2-bis(2,2'-bipyridyl-6-yl)ethane) has yielded new dinuclear andhexanuclear complexes. The FeCl3/NaO2CPh/L (4:4:1) reaction system in MeCN gives red-brown [Fe6O4Cl4(O2CPh)4L2][FeCl4]2 (1). The same reaction system in a 3:3:1 ratio in MeOH gives orange [Fe2(OMe)2Cl2(O2CPh)L][FeCl4] (2). Complex 1·2MeCN: monoclinic, P21/a, a = 15.317(2) Å, b = 18.303(3) Å, c = 16.168(3) Å, 
= 108.91(1)
, and Z = 2. Complex 2: triclinic, P
, a = 14.099(6) Å, b = 18.510(7) Å, c = 7.108(3)Å, 
= 96.77(2), = 99.45(2), 
= 81.16(2), and Z = 2. The cation of 1 consists of a near-planar [Fe6(
3-O)4]10+ core that can be described as three edge-fused [Fe2O2] rhombs to which are attached two additionalFe atoms. The cation of 2 contains a [Fe2(-OMe)2(-O2CPh)]3+ core. In both cations, the L group acts as abridging ligand across an Fe2 unit, with the bpy rings essentially parallel. Variable-temperature solid-state magnetic-susceptibility studies of 1 and 2 in the 2.00-300 K range reveal that for both complexes the data are consistentwith an S = 0 cation and S = 5/2 [FeCl4]- anions. These conclusions were confirmed by magnetization vs fieldstudies in the 2.00-4.00 K and 10.0-50.0 kG ranges. Fitting of the data for 2 to the appropriate theoreticalequation for an equimolar composition of Fe2 cations and [FeCl4]- anions allowed the exchange interaction inthe cation to be determined as J = -10.5 cm-1 (H = -2JS1S2) with g held at 2.00. The obtained J value isconsistent with that predicted by a previously published magnetostructural relationship.
= 108.91(1), and Z = 2. Complex 2: triclinic, P, a = 14.099(6) Å, b = 18.510(7) Å, c = 7.108(3)Å, = 96.77(2), = 99.45(2), = 81.16(2), and Z = 2. The cation of 1 consists of a near-planar [Fe6(3-O)4]10+ core that can be described as three edge-fused [Fe2O2] rhombs to which are attached two additionalFe atoms. The cation of 2 contains a [Fe2(-OMe)2(-O2CPh)]3+ core. In both cations, the L group acts as abridging ligand across an Fe2 unit, with the bpy rings essentially parallel. Variable-temperature solid-state magnetic-susceptibility studies of 1 and 2 in the 2.00-300 K range reveal that for both complexes the data are consistentwith an S = 0 cation and S = 5/2 [FeCl4]- anions. These conclusions were confirmed by magnetization vs fieldstudies in the 2.00-4.00 K and 10.0-50.0 kG ranges. Fitting of the data for 2 to the appropriate theoreticalequation for an equimolar composition of Fe2 cations and [FeCl4]- anions allowed the exchange interaction inthe cation to be determined as J = -10.5 cm-1 (H = -2JS1S2) with g held at 2.00. The obtained J value isconsistent with that predicted by a previously published magnetostructural relationship.