The photochemical route to octahedral iron(V). Primary processes and quantum yields from ultrafast mid-infrared spectroscopy.
The photochemical route to octahedral iron(V). Primary processes and quantum yields from ultrafast mid-infrared spectroscopy.
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八面体铁（V）初级过程的光化学路线和超快中红外光谱的量子产率
DOI：
10.1021/ja5045133
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发表时间：
2014
影响因子：
15
通讯作者：
P. Vöhringer
中科院分区：
文献类型：
--
作者：
H. Vennekate;D. Schwarzer;J. Torres-Alacan;P. Vöhringer
最近，络合物阳离子 [(cyclam-ac)FeIII(N3)]+ 已在低温条件下用于固体基质，作为含有极高氧化态 +5 金属的八面体氮化铁的光化学前体。在这里，我们使用飞秒时间分辨中红外（fs-MIR）光谱和步进扫描傅里叶变换红外光谱研究了室温下液体溶液中这种复杂阳离子的光化学初级事件，这两种光谱都是在可变波长激发下进行的。与冷冻基质实验形成鲜明对比的是，当复合物通过可见光区域中假定的 LMCT 谱带被激发时，无法在液体溶液中检测到光氧化产物。相反，在这些条件下仅观察到叠氮化物阴离子的氧化还原中性解离。然而，有明确的证据表明，当在液体溶液中用紫外光进行光解时，会形成高度氧化的氮化铁产物。然而，光氧化必须与光还原 Fe-N 键断裂竞争，导致叠氮化物自由基和铁 (II) 络合物。氧化还原中性和光还原 Fe-N 键断裂以及光氧化 N-N 键断裂都发生在远低于几百飞秒的时间尺度上。大多数片段会在 10 ps 的时间尺度上发生成对重组回到母体复合体。光氧化的初级量子产率的上限来自 fs-MIR 数据，该上限随着光解光子能量的增加而增加。
Recently, the complex cation [(cyclam-ac)FeIII(N3)]+has been used in solid matrices under cryogenic conditions as a photochemical precursor for an octahedral iron nitride containing the metal at the remarkably high oxidation state +5. Here, we study the photochemical primary events of this complex cation in liquid solution at room temperature using femtosecond time-resolved mid-infrared (fs-MIR) spectroscopy as well as step-scan Fourier-transform infrared spectroscopy, both of which were carried out with variable-wavelength excitation. In stark contrast to the cryomatrix experiments, a photooxidized product cannot be detected in liquid solution when the complex is excited through its putative LMCT band in the visible region. Instead, only a redox-neutral dissociation of azide anions is seen under these conditions. However, clear evidence is found for the formation of the highly oxidized iron nitride product when the photolysis is carried out in liquid solution with UV light. Yet, the photooxidation must compete with photoreductive Fe–N bond cleavage leading to azide radicals and an iron(II) complex. Both, redox-neutral and photoreductive Fe–N bond breakage as well as photooxidative N–N bond breakage occur on a time scale well below a few hundred femtoseconds. The majority of fragments suffer from geminate recombination back to the parent complex on a time scale of 10 ps. Upper limits of the primary quantum yield for photooxidation are derived from the fs-MIR data, which increase with increasing energy of the photolysis photon.
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影响因子：
15
作者：
Peter Portius;Jixin Yang;Xue-Zhong Sun;D. Grills;P. Matousek;A. Parker;M. Towrie;M. George
通讯作者：
Peter Portius;Jixin Yang;Xue-Zhong Sun;D. Grills;P. Matousek;A. Parker;M. Towrie;M. George
影响因子：
--
作者：
Joel Torres-Alacan;Ujjal Das;A. C. Filippou;P. Vöhringer
通讯作者：
Joel Torres-Alacan;Ujjal Das;A. C. Filippou;P. Vöhringer
激光光解产生的硝基铁(V)卟啉中间体的共振拉曼光谱
影响因子：
15
作者：
W. Wagner;K. Nakamoto
通讯作者：
K. Nakamoto
影响因子：
4.6
作者：
Rohde, Jan-Uwe;Betley, Theodore A.;Que, Lawrence, Jr.
通讯作者：
Que, Lawrence, Jr.
影响因子：
15
作者：
Scepaniak, Jeremiah J.;Fulton, Meita D.;Smith, Jeremy M.
通讯作者：
Smith, Jeremy M.