Synthesis and Characterization of Aluminum Complexes of Redox-Active Pyridyl Nitroxide Ligands
详细信息 查看全文
- 作者：Andrew M. Poitras ; Justin A. Bogart ; Bren E. Cole ; Patrick J. Carroll ; Eric J. Schelter ; Christopher R. Graves
- 刊名：Inorganic Chemistry
- 出版年：2015
- 出版时间：November 16, 2015
- 年：2015
- 卷：54
- 期：22
- 页码：10901-10908
- 全文大小：450K
- ISSN：1520-510X
文摘
The aluminum complexes (RpyNO鈥?/sup>)2AlCl (RpyNO鈥?/sup> = N-tert-butyl-N-(2-pyridyl)nitroxyl; R = H (1), CH3 (2), CF3 (3)) were prepared in 80鈥?8% yield through the protonolysis reaction between the pyridyl hydroxylamine ligand precursors RpyNOH and dimethylaluminum chloride. Complex 1 was also prepared using a salt metathesis route in 92% yield. Complexes 1鈥?b>3 were characterized using 1H and 13C NMR spectroscopies. Single-crystal X-ray diffraction analysis of the complexes revealed that 1鈥?b>3 are isostructural, with the AlIII cation in all cases being five coordinate with distorted square pyramidal geometries. The geometry of complex 1 was studied using DFT, which showed primarily ligand-based frontier molecular orbitals. Reaction of 1 with NaOt-Bu gave (pyNO鈥?/sup>)2AlOt-Bu (4), while reaction of 1 with AgBPh4 gave [(pyNO鈥?/sup>)2Al(THF)2][BPh4] (5) in 54% and 87% yields, respectively. Compounds 4 and 5 were both characterized using 1H and 13C NMR spectroscopies and compound 5 by X-ray diffraction. Complexes 1鈥?b>5 were also characterized by UV鈥搗is electronic absorption spectroscopy and electrochemistry. The cyclic voltammograms of the complexes show two separate oxidation process, the potentials of which are dependent on both the substitution pattern of the RpyNO鈥?/sup> ligands and the anion that completes the aluminum coordination sphere. A correlation was determined between the chemical shift of the t-Bu of the RpyNO鈥?/sup> ligand in the 1H NMR spectroscopy and the potentials of the redox events for complexes 1鈥?b>4.
© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号 地址：北京市海淀区学院路29号 邮编：100083 电话：办公室：(+86 10)66554848；文献借阅、咨询服务、科技查新：66554700 |