Synthesis and Characterization of Iron(III) Complexes of 5‐(8‐Carboxy‐1‐naphthyl)‐10, 15, 20‐tritolyl Porphyrin |
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| Authors: | Yu Zhang Jiaxun Jiang Chuanjiang Hu |
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| Affiliation: | 1. Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, P.R. China;2. State Key Lab & Coordination Chemistry Institute, Nanjing University, Nanjing 210093, P. R. China |
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| Abstract: | ![]()
5‐(8‐Carboxy‐1‐naphthyl)‐10, 5, 20‐tritolyl porphyrin (H3CNTTP) and its iron(III) complexes, [Fe(CNTTP)]2 and [Fe(CNTTP)(N‐MeIm)2], were synthesized and characterized. X‐ray crystallography revealed that the carboxylate group is “hanging” over the porphyrin plane. The rigid framework makes the distance between the carboxylate oxygen and iron in the same porphyrin too long to form a coordination bond. On the other hand, the carboxylate group is not bulky enough to block the axial binding site. In the presence of OH–, the carboxylate oxygen is coordinated to iron in the symmetry‐related unit, which led to the dimeric structure, [Fe(CNTTP)]2. In the presence of excess N‐methylimidazole, a six‐coordinate species, [Fe(CNTTP)(N‐MeIm)2], was obtained. In such a structure, CH ··· O interactions between the carboxylate group and imidazole probably play an important role to determine the orientation of imidazole plane. Two imidazole planes have relative parallel orientation. For [Fe(CNTTP)(N‐MeIm)2], 1H NMR shows pyrrole protons at the region –10 to –25 ppm. EPR shows rhombic spectrum. Those suggest [Fe(CNTTP)(N‐MeIm)2] is a type II low‐spin iron(III) porphyrinate. |
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| Keywords: | Iron porphyrin Carboxylate Imidazole Iron CH· · · O interactions |
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