Iron Complexes Derived from {nacnac-(CH2py)2}鈭?/sup> and {nacnac-(CH2py)(CHpy)}n Ligands: Stabilization of Iron(II) via Redox Noninnocence
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- 作者：Valerie A. Williams ; Peter T. Wolczanski ; J枚rg Sutter ; Karsten Meyer ; Emil B. Lobkovsky ; Thomas R. Cundari
- 刊名：Inorganic Chemistry
- 出版年：2014
- 出版时间：May 5, 2014
- 年：2014
- 卷：53
- 期：9
- 页码：4459-4474
- 全文大小：882K
- 年卷期：v.53,no.9(May 5, 2014)
- ISSN：1520-510X
文摘
Nacnac-based tetradentate chelates, {nacnac-(CH2py)2}鈭?/sup> ({nn(PM)2}鈭?/sup>) and {nacnac-(CH2py)(CHpy)}n ({nn(PM)(PI)}n) have been investigated in iron complexes. Treatment of Fe{N(TMS)2}2(THF) with {nn(PM)2}H afforded {nn(PM)2}FeN(TMS)2 [1-N(TMS)2], which led to {nn(PM)2}FeCl (1-Cl) from HCl and to {nn(PM)2}FeN3 (1-N3) upon salt metathesis. Dehydroamination of 1-N(TMS)2 was induced by L (L = PMe3, CO) to afford {nn(PM)(PI)}Fe(PMe3)2 [2-(PMe3)2] and {nn(PM)(PI)}FeCO (3-CO). Substitution of 2-(PMe3)2 led to {nn(PM)(PI)}Fe(PMe3)CO [2-(PMe3)CO], and exposure to a vacuum provided {nn(PM)(PI)}Fe(PMe3) (3-PMe3). Metathesis routes to {nn(PM)(PI)}FeL2 (2-L2; L = PMe3, PMe2Ph) and {nn(PM)(PI)}FeL (3-L; L = PMePh2, PPh3) from [{nn(PM)(PI)}2鈥?/sup>]Li2 and FeBr2(THF)2 in the presence of L proved feasible, and 1e鈥?/sup> and 2e鈥?/sup> oxidation of 2-(PMe3)2 afforded 2+-(PMe3)2 and 22+-(PMe3)2 salts. M枚ssbauer spectroscopy, structural studies, and calculational assessments revealed the dominance of iron(II) in both high-spin (1-X) and low-spin (2-L2 and 3-L) environments, and the redox noninnocence (RNI) of {nn(PM)(PI)}n [2-L2, 3-L, n = 2鈥? 2+-(PMe3)2, n = 1鈥? 22+-(PMe3)2, n = 0]. A discussion regarding the utility of RNI in chemical reactivity is proffered.