Insights into the naphthalenide-driven synthesis and reactivity of zerovalent iron nanoparticles.
Insights into the naphthalenide-driven synthesis and reactivity of zerovalent iron nanoparticles.
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洞察萘驱动的零价铁纳米粒子的合成和反应性
DOI：
10.1039/d1dt02523f
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发表时间：
2021
影响因子：
4
通讯作者：
C. Feldmann
中科院分区：
文献类型：
--
作者：
A. Reiß;C. Donsbach;C. Feldmann
考察了作为强力还原剂的碱金属萘系化合物的化学稳定性和热稳定性，包括碱金属类型([Linaph]和[Nanaph])、溶剂类型(四氢呋喃、二甲醚)、温度(−30~+50℃)和储存时间(0~12h)。通过紫外-可见光谱和朗伯-比尔定律定量了[LiNaph]/[NaNaph]的稳定性和浓度。结果表明，在低温下，[LiNaph]在THF中的溶液最稳定。分解可能与溶剂的还原聚合有关。在四氢呋喃中最稳定的[LiNaph]溶液被用于通过还原FeCl3在四氢呋喃中制备具有活性的零价铁纳米颗粒，尺寸为2.3±0.3 nm。最后，研究了[LiNaph]和/或起始原料和溶剂的残留物对所制备的Fe(0)纳米粒子在选定配体存在下用碘控制氧化的影响，得到了四种新的单晶铁化合物([FeI2(MeOH)2]，([MePPh3][FeI3(Ph3p)])4·PPh3·6C7H8，[FeI2(PPh3)2]和[FeI2(18-冠-6)]。因此，可以通过[LiNaph]驱动的还原在液相中获得活性Fe(0)纳米颗粒，并在瞬间反应得到新的化合物，而不留有初始还原的残留物(例如LiCl2、Na2+和THF)。
The chemical and thermal stability of alkali metal naphthalenides as powerful reducing agents are examined, including the type of alkali metal ([LiNaph] and [NaNaph]), the type of solvent (THF, DME), the temperature (−30 to +50 °C), and the time of storage (0 to 12 hours). The stability and concentration of [LiNaph]/[NaNaph] are quantified via UV-Vis spectroscopy and the Lambert–Beer law. As a result, the solutions of [LiNaph] in THF at low temperature turn out to be most stable. The decomposition can be related to a reductive polymerization of the solvent. The most stable [LiNaph] solutions in THF are exemplarily used to prepare reactive zerovalent iron nanoparticles, 2.3 ± 0.3 nm in size, by reduction of FeCl3 in THF. Finally, the influence of [LiNaph] and/or remains of the starting materials and solvents upon controlled oxidation of the as-prepared Fe(0) nanoparticles with iodine in the presence of selected ligands is evaluated and results in four novel, single-crystalline iron compounds ([FeI2(MeOH)2], ([MePPh3][FeI3(Ph3P)])4·PPh3·6C7H8, [FeI2(PPh3)2], and [FeI2(18-crown-6)]). Accordingly, reactive Fe(0) nanoparticles can be obtained in the liquid phase via [LiNaph]-driven reduction and instantaneously reacted to give new compounds without remains of the initial reduction (e.g. LiCl, naphthalene, and THF).