Xanthene-modified and hangman iron corroles.
Xanthene-modified and hangman iron corroles.
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DOI：
10.1021/ic101943h
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发表时间：
2011-01
影响因子：
4.6
通讯作者：
M. Schwalbe;Dilek K Dogutan;S. Stoian;Thomas S. Teets;D. Nocera
中科院分区：
文献类型：
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作者：
M. Schwalbe;Dilek K Dogutan;S. Stoian;Thomas S. Teets;D. Nocera
用氧杂蒽支架修饰的铁可腐蚀物在缩短的反应时间内从容易获得的起始材料递送。这些新的铁腐蚀物已被光谱检查，特别强调定义的金属中心的氧化态。利用（57）Fe穆斯堡尔谱学结合密度泛函理论（DFT）计算研究了它们的电子结构，揭示了咔咯配体的非无辜性。虽然这些铁corroles包含一个正式的Fe（IV）中心，去质子化的咔咯大环配体是一个电子氧化。这些配合物的电子基态被最好地描述为一个中间自旋S = 3/2 Fe（III）位点与单价二价阴离子corrole [Fe（III）Cl-corrole（+·）]的S = 1/2强反铁磁耦合。我们在这里表明，铁corroles以及氧杂蒽改性和hangman氧杂蒽铁corroles是氧化还原活性和催化过氧化氢通过过氧化氢酶反应，并与氧化电位的规模，这种活动。在过氧化氢酶周转过程中，咔咯大环的中位易受亲核攻击。过氧化物的反应性在这里报告的刽子手裂缝增加了新兴的主题，corroles是善于催化各种底物中的氧-氧键的双电子活化。
Iron corroles modified with a xanthene scaffold are delivered from easily available starting materials in abbreviated reaction times. These new iron corroles have been spectroscopically examined with particular emphasis on defining the oxidation state of the metal center. Investigation of their electronic structure using (57)Fe Mössbauer spectroscopy in conjunction with density functional theory (DFT) calculations reveals the non-innocence of the corrole ligand. Although these iron corroles contain a formal Fe(IV) center, the deprotonated corrole macrocycle ligand is one electron oxidized. The electronic ground state of these complexes is best described as an intermediate spin S = 3/2 Fe(III) site strongly antiferromagnetically coupled to the S = 1/2 of the monoradical dianion corrole [Fe(III)Cl-corrole(+•)]. We show here that iron corroles as well as xanthene-modified and hangman xanthene iron corroles are redox active and catalyze the disproportionation of hydrogen peroxide via the catalase reaction, and that this activity scales with the oxidation potential. The meso position of corrole macrocycle is susceptible toward nucleophilic attack during catalase turnover. The reactivity of peroxide within the hangman cleft reported here adds to the emerging theme that corroles are good at catalyzing two-electron activation of the oxygen-oxygen bond in a variety of substrates.