二甲基中卟啉-IX-阿托吡啶钴（II）可逆氧合作用的磁圆二色性

Magnetic circular dichroism on the reversible oxygenation of dimethylmesoporphyrin-IX-atopyridinecobalt (II).

作者信息

Nozawa T, Hatano M, Yamamoto H, Kwan T

出版信息

Bioinorg Chem. 1976;5(3):267-73. doi: 10.1016/s0006-3061(00)82025-6.

DOI:10.1016/s0006-3061(00)82025-6

Abstract

The magnetic circular dichroism spectra were measured for the dimethylmesoporphyrin-IX-atocobalt complexes. As expected dimethylmesoporphyrin-IX-atocobalt (III) and its pyridine complex exhibited the MCD for a typical D4h metalloporphyrins. Dimethylmesoporphyrin-IX-atocobalt (II) and its pyridine complex showed a paramagnetic effect on the MCD especially in the Soret region. A very atypical Soret MCD for the oxygenated dimethylmesoporphyrin-IX-atopyridinecobalt (II) was attributed to the existence of a CT band associated with oxygen from the similarity to the MCD for oxymyoglobin. Temperature-dependent MCD change for the cobalt (II) oxygen complex revealed the reversible oxygen binding to dimethylmesoporphyrin-IX-atopyridinecobalt (II) with KO2 of 3.2 X 10(-3) in (mmHg)-1 at 228 degrees K.

摘要

测量了二甲基中卟啉-IX-阿托钴配合物的磁圆二色光谱。如预期的那样，二甲基中卟啉-IX-阿托钴（III）及其吡啶配合物呈现出典型D4h金属卟啉的磁圆二色性。二甲基中卟啉-IX-阿托钴（II）及其吡啶配合物对磁圆二色性表现出顺磁效应，特别是在索雷特区域。氧化的二甲基中卟啉-IX-阿托吡啶钴（II）的非常不典型的索雷特磁圆二色性归因于与氧相关的电荷转移带的存在，这是因为它与氧合肌红蛋白的磁圆二色性相似。钴（II）氧配合物的磁圆二色性随温度的变化表明，在228 K时，氧与二甲基中卟啉-IX-阿托吡啶钴（II）可逆结合，结合常数KO2为3.2×10(-3)（mmHg）-1。