Homoleptic Cerium(III) and Cerium(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State
详细信息 查看全文
- 作者：Justin A. Bogart ; Andrew J. Lewis ; Scott A. Medling ; Nicholas A. Piro ; Patrick J. Carroll ; Corwin H. Booth ; Eric J. Schelter
- 刊名：Inorganic Chemistry
- 出版年：2013
- 出版时间：October 7, 2013
- 年：2013
- 卷：52
- 期：19
- 页码：11600-11607
- 全文大小：403K
- 年卷期：v.52,no.19(October 7, 2013)
- ISSN：1520-510X
文摘
Electrochemical experiments performed on the complex CeIV[2-(tBuNO)py]4, where [2-(tBuNO)py]鈭?/sup> = N-tert-butyl-N-2-pyridylnitroxide, indicate a 2.51 V stabilization of the 4+ oxidation state of Ce compared to [nBu4N]2[Ce(NO3)6] in acetonitrile and a 2.95 V stabilization compared to the standard potential for the ion under aqueous conditions. Density functional theory calculations suggest that this preference for the higher oxidation state is a result of the tetrakis(nitroxide) ligand framework at the Ce cation, which allows for effective electron donation into, and partial covalent overlap with, vacant 4f orbitals with 未 symmetry. The results speak to the behavior of CeO2 and related solid solutions in oxygen uptake and transport applications, in particular an inherent local character of bonding that stabilizes the 4+ oxidation state. The results indicate a cerium(IV) complex that has been stabilized to an unprecedented degree through tuning of its ligand-field environment.