Enhanced electron-transfer reactivity of nonheme manganese(IV)-oxo complexes by binding scandium ions.
Enhanced electron-transfer reactivity of nonheme manganese(IV)-oxo complexes by binding scandium ions.
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DOI：
10.1021/ja403965h
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发表时间：
2013-06-19
影响因子：
15
通讯作者：
Fukuzumi, Shunichi
中科院分区：
文献类型：
--
作者：
Yoon, Heejung;Lee, Yong-Min;Wu, Xiujuan;Cho, Kyung-Bin;Sarangi, Ritimukta;Nam, Wonwoo;Fukuzumi, Shunichi
1个和2个Sc~(3+)离子分别与非血红素锰(IV)氧配合物[(N4Py)MnIV(O)]2+(N4Py=N，N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine)和[(Bn-TPEN)MnIV(O)]2+(Bn-TPEN=N-苄基-N，N‘，N’-三(2-吡啶甲基)-1，2-二氨基乙烷)形成MnIV(O)-(SC3+)1和MnIV(O)-(SC3+)2络合物。用光谱方法和密度泛函理论计算研究了SC3+与MnIV(O)络合物的结合。由于SC3+离子的结合，MnIV(O)络合物的单电子还原电位明显向正方向移动。因此，通过两个Sc3+离子的结合，MnIV(O)络合物的电子转移反应速度提高了107倍。根据马库斯电子转移理论，考察和分析了不同电子给体对MnIV(O)和MnIV(O)-(SC3+)2络合物电子转移的驱动力依赖性，确定了电子转移的重组能。由于MnIV(O)-(SC3+)2络合物具有较小的重组能和较大的正还原电势，使其电子转移反应活性显著增强。由于SC3+与MnIV(O)络合物的结合，大大提高了MnIV(O)络合物的电子转移活性，导致MnIV(O)络合物对硫代苯甲醚的亚磺化反应机理发生了变化，从没有金属离子结合的直接氧原子转移途径转变为有Sc3+离子结合的电子转移途径。
One and two scandium ions (Sc3+) are bound strongly to nonheme manganese(IV)–oxo complexes, [(N4Py)MnIV(O)]2+ (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) and [(Bn-TPEN)MnIV(O)]2+ (Bn-TPEN = N-benzyl-N,N′,N′-tris(2-pyridylmethyl)-1,2-diaminoethane), to form MnIV(O)–(Sc3+)1 and MnIV(O)–(Sc3+)2 complexes, respectively. The binding of Sc3+ ions to the MnIV(O) complexes was examined by spectroscopic methods as well as by DFT calculations. The one-electron reduction potentials of the MnIV(O) complexes were markedly shifted to a positive direction by binding of Sc3+ ions. Accordingly, rates of the electron transfer reactions of the MnIV(O) complexes were enhanced as much as 107–fold by binding of two Sc3+ ions. The driving force dependence of electron transfer from various electron donors to the MnIV(O) and MnIV(O)–(Sc3+)2 complexes was examined and analyzed in light of the Marcus theory of electron transfer to determine the reorganization energies of electron transfer. The smaller reorganization energies and much more positive reduction potentials of the MnIV(O)–(Sc3+)2 complexes resulted in remarkable enhancement of the electron-transfer reactivity of the MnIV(O) complexes. Such a dramatic enhancement of the electron-transfer reactivity of the MnIV(O) complexes by binding of Sc3+ ions resulted in the change of mechanism in the sulfoxidation of thioanisoles by MnIV(O) complexes from a direct oxygen atom transfer pathway without metal ion binding to an electron-transfer pathway with binding of Sc3+ ions.
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影响因子：
4.3
作者：
Arunkumar, Chellaiah;Lee, Yong-Min;Nam, Wonwoo
通讯作者：
Nam, Wonwoo
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD
影响因子：
18.3
作者：
Cho, Jaeheung;Sarangi, Ritimukta;Wonwoo Nam
通讯作者：
Wonwoo Nam
影响因子：
4.4
作者：
BECKE, AD
通讯作者：
BECKE, AD
影响因子：
4.6
作者：
Arias, J;Newlands, CR;Abu-Omar, MM
通讯作者：
Abu-Omar, MM