Novel routes for the modification of iron porphyrins

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• 作者：Latos-Grazynski ; Lechoslaw ; Rachlewicz ; Krystyna ; Wojaczynski ; Jacek
• 关键词：Iron porphyrins ; Cation radicals ; NMR
• 刊名：Coordination Chemistry Reviews
• 出版年：1999
• 出版时间：September, 1999
• 年：1999
• 卷：190-192
• 期：Complete
• 页码：109-125
• 全文大小：240 K

文摘

The effects of unconventional modifications of iron tetraarylporphyrins on their electronic structure and chemical properties were examined. The alterations included the β(meso)-substitution or an oxygen atom insertion into an iron–nitrogen bond. The profound transformation of porphyrin to 2-pyridiniumylporphyrin, isoporphyrin or porphodimethene occurred in reactions involving iron porphyrin in highly-oxidized states and pyridine. Addition of 2,4,6-collidine generated iron porphyrin N-oxides. The 2-hydroxy substituted tetraphenylporphyrin (a hybrid-type ligand) coordinates using a tetranitrogen macrocyclic center and an ionized hydroxy group of the periphery to form the cyclic trimer [(2-O–TPP)Fe(III)]₃. The seven pyrrole protons of (2-X-TPP)Fe(III)Cl and [(2-X–TPP)Fe(III)(CN)₂] provided the direct probe of the spin density distribution around the porphyrin macrocycle as determined by ¹H-NMR. Studies on the controlled modification of the tetraarylporphyrin periphery also included a symmetrical modification of a single pyrrole ring to obtain iron(III) quinoxalinoporphyrin characterized by the less common (d_xzd_yz)⁴(d_xy)¹ low-spin ground electronic state of the bis-cyanide derivative [(QTPP)Fe(III)(CN)₂]⁻.