Oxygen-cobalt chemistry using a porphyrinogen platform.
Oxygen-cobalt chemistry using a porphyrinogen platform.
复制标题
使用卟啉原平台的氧钴化学。
DOI：
10.1021/ic802102k
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发表时间：
2009
影响因子：
4.6
通讯作者：
S. Sarkar
中科院分区：
文献类型：
--
作者：
D. Bhattacharya;S. Maji;K. Pal;S. Sarkar
Co（II）卟啉原络合物的四乙基铵盐，[Et（4）N]（2）[LCo（II）]，1，（L =四（环己基）卟啉原四阴离子）被大气氧氧化形成[Et（4）N][LCo（III）]，2，与Co（II）卟啉原的配体氧化[Li（THF）（2）]（2）[L 'Co（II）]相反（L' =八乙基卟啉原四阴离子）与纯氧（Angelis，S. D.的; Solari，E.; Floriani，C.; Chiesi-Villa，A.;里佐利角J. Am. 1994，116，5702）。用四乙基铵阳离子（[Et（4）N]（+））取代[Li（THF）（2）]（2）[L 'Co（II）]的吡咯基环周围的η（4）键合的锂阳离子（[Li（THF）（2）]（+）导致类似于1与氧的金属中心氧化还原反应，因此证明反应性的差异是由于抗衡阳离子的变化而不是外围配体的取代。[Et（4）N][LCo（III）]，2与元素碘反应产生[L（DeltaDelta）Co（II）-I]（I（3））（I（2）），3。该反应被认为是碘诱导的电子转移反应，通过Co（III）-卟啉原，其中源自内部还原剂（卟啉原）氧化成卟啉二甲烯的四个电子被内部氧化剂（Co（III））和外部氧化剂（碘）共享，分别导致还原成Co（II）和碘化物。配合物2和3，其特征在于通过光谱研究，循环伏安法（CV），磁矩测量，并通过单晶X-射线衍射研究。基于密度泛函理论（DFT）框架分析了2的结构性质.
The tetraethylammonium salt of the Co(II)porphyrinogen complex, [Et(4)N](2)[LCo(II)], 1, (L = tetrakis(cyclohexyl)porphyrinogen tetraanion) is oxidized by atmospheric oxygen to form [Et(4)N][LCo(III)], 2, in contrast to the ligand oxidation of Co(II)porphyrinogen, [Li(THF)(2)](2)[L'Co(II)] (L' = octaethylporphyrinogen tetraanion) with pure oxygen (Angelis, S. D.; Solari, E.; Floriani, C.; Chiesi-Villa, A.; Rizzoli, C. J. Am. Chem. Soc. 1994, 116, 5702). Substitution of the eta(4)-bound lithium cation ([Li(THF)(2)](+)) on the periphery of the pyrollyl ring of [Li(THF)(2)](2)[L'Co(II)] with a tetraethylammonium cation ([Et(4)N](+)) resulted in a metal-centered redox reaction analogous to that of 1 with oxygen, and thus demonstrated that the difference in reactivity is due to the change in the countercation rather than the substitution of the peripheral ligand. Reaction of [Et(4)N][LCo(III)], 2, with elemental iodine produced [L(DeltaDelta)Co(II)-I](I(3))(I(2)), 3. This reaction is viewed as an iodine-induced electron transfer reaction across Co(III)-porphyrinogen, in which the four electrons that originated from the oxidation of the internal reductant (porphyrinogen) to porphodimethene are shared by the internal oxidant (Co(III)), and the external oxidant (iodine), resulting in the reduction to Co(II) and iodide, respectively. Complexes 2 and 3 were characterized by spectroscopic studies, cyclic voltammetry (CV), magnetic moment measurements, and by single-crystal X-ray diffraction studies. The structural properties of 2 were analyzed based on the density functional theoretical (DFT) framework.