Sn(III) and Ge(III) in the Thiophenolato-Bridged Complexes [LFeSnFeL]n+ and [LFeGeFeL]n+ (n = 2, 3; L = 1,4,7-(4-tert-Butyl-2-me
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- 作者：Thorsten Glaser ; Eckhard Bill ; Thomas Weyhermü ; ller ; Wolfram Meyer-Klaucke ; and Karl Wieghardt
- 刊名：Inorganic Chemistry
- 出版年：1999
- 出版时间：May 31, 1999
- 年：1999
- 卷：38
- 期：11
- 页码：2632 - 2642
- 全文大小：201K
- 年卷期：v.38,no.11(May 31, 1999)
- ISSN：1520-510X
文摘
The reaction of mononuclear [LFeIII] where L represents the trianionic ligand 1,4,7-tris(4-tert-butyl-2-mercaptobenzyl)-1,4,7-triazacyclononane with Pb(ClO4)2·3H2O in methanol affords the heterotrinuclear complex[LFePbFeL](ClO4)2 (1). Similarly, with SnSO4 or GeI2 as starting material in an acetonitrile/water mixture andCH2Cl2, respectively, the reaction with [LFeIII] yields crystalline materials of [LFeSnFeL](PF6)2 (2a) and[LFeGeFeL](PF6)2 (3a) upon addition of NaPF6. Complexes 2a and 3a can be one-electron oxidized by [NiIII(tacn)2](ClO4)3 (tacn = 1,4,7-triazacyclononane) to give [LFeSnFeL](ClO4)3 (2b) and [LFeGeFeL](ClO4)3 (3b).The crystal structures of [LFeSnFeL](BPh4)2·6CH3CN (2a*), [LFeSnFeL](ClO4)3·4.5(CH3)2CO (2b*), and[LFeGeFeL](BPh4)2·6CH3CN (3a*) have been determined by single-crystal X-ray crystallography. The trinuclearcations consist of three face-sharing octahedra connected by six thiolato bridges affording the core N3Fe(
-S)3M(-S)3FeN3 (M = Sn,Ge). Fe and Sn(Ge) K edge X-ray absorption spectroscopy on 2a, 2b, and 3a, 3b establishedthat the one-electron oxidations affect exclusively the iron ions whereas the oxidation state of the central Sn(Ge)remains unaffected. 119Sn(57Fe) Mössbauer spectroscopy, magnetochemistry, and EPR spectroscopy prove thatboth the Sn and Ge ions in the di- and trications are trivalent since the unpaired electron in 2b and 3b displayssubstantial 5s and 4s character, respectively. In contrast, in 1, an oxidation state distribution of l.s.FeIIIPbIIl.s.FeIIIprevails. Complexes 1, 2a, and 3a possess a diamagnetic ground state whereas 2b and 3b have an St = 1/2 groundstate.
-S)3M(-S)3FeN3 (M = Sn,Ge). Fe and Sn(Ge) K edge X-ray absorption spectroscopy on 2a, 2b, and 3a, 3b establishedthat the one-electron oxidations affect exclusively the iron ions whereas the oxidation state of the central Sn(Ge)remains unaffected. 119Sn(57Fe) Mössbauer spectroscopy, magnetochemistry, and EPR spectroscopy prove thatboth the Sn and Ge ions in the di- and trications are trivalent since the unpaired electron in 2b and 3b displayssubstantial 5s and 4s character, respectively. In contrast, in 1, an oxidation state distribution of l.s.FeIIIPbIIl.s.FeIIIprevails. Complexes 1, 2a, and 3a possess a diamagnetic ground state whereas 2b and 3b have an St = 1/2 groundstate.