Photoinitiated Reactivity of a Thiolate-Ligated, Spin-Crossover Nonheme {FeNO}(7) Complex with Dioxygen.
Photoinitiated Reactivity of a Thiolate-Ligated, Spin-Crossover Nonheme {FeNO}(7) Complex with Dioxygen.
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DOI：
10.1021/jacs.5b12741
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发表时间：
2016-03-09
影响因子：
15
通讯作者：
Goldberg DP
中科院分区：
文献类型：
--
作者：
McQuilken AC;Matsumura H;Dürr M;Confer AM;Sheckelton JP;Siegler MA;McQueen TM;Ivanović-Burmazović I;Moënne-Loccoz P;Goldberg DP
非血红素铁络合物[Fe（NO）（N3 PyS）] BF 4是{FeNO}7物种的一个罕见的例子，表现出自旋交叉行为。低温和高温下的X射线晶体学研究和变温磁化率测量的比较表明，低自旋S = 1/2基态在0-150 K处布居，而低自旋S = 1/2和高自旋S = 3/2态在T > 150 K处布居。这些结果解释了[Fe（NO）（N3 PyS）] BF 4在室温下在CD 3CN中在1737和1649 cm−1处观察到的两个N-O振动模式。该{FeNO}7络合物在乙腈中用可见光照射后与分子氧反应，生成硫醇盐连接的非血红素铁（III）-硝基络合物[FeIII（NO2）（N3 PyS）]+，其特征在于EPR，FTIR，UV-vis和CSI-MS。同位素标记研究，结合FTIR和CSI-MS，表明来自O2的一个O原子被并入FeIII-NO2产物中。[Fe（NO）（N3 PyS）] BF 4在甲醇中的O2反应性与CH 3CN显著不同，仅导致硫基氧化，而不是NO·氧化。提出了一种机制，涉及形成FeIII-superoxo和FeIII-过氧亚硝酸盐中间体的NO·氧化反应，并考虑到实验观察。FeIII-亚硝酸根络合物的稳定性是有限的，并且[FeIII（NO2）（N3 PyS）]+的衰变导致{FeNO}7物种和硫氧化产物。这项工作表明，单个单核、硫醇盐连接的非血红素{FeNO}7复合物可以表现出与一氧化氮双加氧酶（NOD）和亚硝酸还原酶（NiR）活性相关的反应性。硫醇供体的存在下是至关重要的两个途径，这些生物相关的过程和机制的见解。
The nonheme iron complex, [Fe(NO)(N3PyS)]BF4, is a rare example of an {FeNO}7 species that exhibits spin-crossover behavior. The comparison of X-ray crystallographic studies at low and high temperatures and variable-temperature magnetic susceptibility measurements show that a low-spin S = 1/2 ground state is populated at 0–150 K, while both low-spin S = 1/2 and high-spin S = 3/2 states are populated at T > 150 K. These results explain the observation of two N–O vibrational modes at 1737 and 1649 cm−1 in CD3CN for [Fe(NO)(N3PyS)]BF4 at room temperature. This {FeNO}7 complex reacts with dioxygen upon photoirradiation with visible light in acetonitrile to generate a thiolate-ligated, nonheme iron(III)-nitro complex, [FeIII(NO2)(N3PyS)]+, which was characterized by EPR, FTIR, UV–vis, and CSI-MS. Isotope labeling studies, coupled with FTIR and CSI-MS, show that one O atom from O2 is incorporated in the FeIII–NO2 product. The O2 reactivity of [Fe(NO)(N3PyS)]BF4 in methanol is dramatically different from CH3CN, leading exclusively to sulfur-based oxidation, as opposed to NO· oxidation. A mechanism is proposed for the NO· oxidation reaction that involves formation of both FeIII-superoxo and FeIII-peroxynitrite intermediates and takes into account the experimental observations. The stability of the FeIII-nitrite complex is limited, and decay of [FeIII(NO2)(N3PyS)]+ leads to {FeNO}7 species and sulfur oxygenated products. This work demonstrates that a single mononuclear, thiolate-ligated nonheme {FeNO}7 complex can exhibit reactivity related to both nitric oxide dioxygenase (NOD) and nitrite reductase (NiR) activity. The presence of the thiolate donor is critical to both pathways, and mechanistic insights into these biologically relevant processes are presented.
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影响因子：
4.1
作者：
Gunaydin, Hakan;Houk, K. N.
通讯作者：
Houk, K. N.
DOI：
10.1073/pnas.95.18.10378
发表时间：
1998-09-01
影响因子：
11.1
作者：
Gardner, PR;Gardner, AM;Salzman, AL
通讯作者：
Salzman, AL
DOI：
10.1073/pnas.84.18.6369
发表时间：
1987-09-01
影响因子：
11.1
作者：
IYENGAR, R;STUEHR, DJ;MARLETTA, MA
通讯作者：
MARLETTA, MA
影响因子：
82.9
作者：
Cosby, K;Partovi, KS;Gladwin, MT
通讯作者：
Gladwin, MT
影响因子：
3.2
作者：
Gonzalez-Ovalle, Luis E.;Quesne, Matthew G.;de Visser, Sam P.
通讯作者：
de Visser, Sam P.