Electron Spin Resonance Studies of Internal Rotation of Nitrosyl Axial Ligand in Heme Complexes.

血红素复合物中亚硝基轴向配体内部旋转的电子自旋共振研究。

• 批准号: 08672485
• 负责人: SATO Mitsuo
• 金额: $ 0.38万
• 依托单位: Teikyo University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08672485/
• 关键词: ESR; Nitrosyl heme complex; Internal rotation of axial ligand; ESR of nitrosyl heme; Modified Bloch equation; Stochastic Liouville method; ESRスペクトルの温度変化; ESRスペクトル

A number of 5-coordinate nitrosyl heme complexes have been prepared and studied by ESR spectroscopy. Of these Fe (TMP)^<15>NO in toluene has been meaured in most detail in the temperature range between 10 and 380 K,where TMP is tetramesitylporphyrin. The spectral pattern showed a drastic change from rhombic one at lower temperatures (g_1*g_2g_3,10-120K) to axial one at intermediate temperatures (g_1=g_2g_3,120-200K) and to isotropic one at higher temperatures (g_1=g_2=g_3,200-380K). Furthermore, the spectra of rhombic symmetry showed extra absorption peaks near (g_1+g_2)/2 above 40 K,which, gaining intensities with raise in temperature, became the perpendicular peaks of axially symmetric spectra at intermediate temperatures. The observed spectra are analyzed using modified Bloch equations and the stochastic Liouville method. The temperature dependent spectra have been interpreted in terms of the 90ﾟ jump-internal-rotation (R_2) of axially coordinated nitrosyl ligand in addition to the Brownian rotational motion (R_1) of nitrosyl heme complexes, both motions become fast with increasing temperature. Specifically, both the rates of R_1 and R_2 are fast enough at higher temperatures to average out the magnetic anisotropies. R_1 become slower in rate with decreasing temperature and is essentially frozen out near 200 K,while the rate of R_2 is so fast to average out the g_1-g_2 anisotropy above 120 K and is still fast to cause the extra peaks above 40 K.

合成了一系列5配位亚硝基血红素络合物，并用ESR波谱对其进行了研究。在这些化合物中，甲苯中的Fe(TMP)_(15)和NO已在10~380 K的温度范围内得到了最详细的测量，其中TMP是四甲苯基卟啉。在较低温度(g_1*g_2g_3，10-120K)下由菱形谱型向中温(g_1=g_2g_3,120-200K)的轴向谱型和较高温度(g_1=g_2=g_3,200-380K)的各向同性谱型转变。此外，在40K以上，在(g_1+g_2)/2附近出现了菱形对称性的额外吸收峰，并随着温度的升高而增强，在中温区成为轴对称吸收峰的垂直峰。用修正的Bloch方程和随机Liouville方法对观测光谱进行了分析。用轴向配位亚硝基配体的90ﾟ跳跃内旋转(R_2)和亚硝基血红素络合物的布朗自转运动(R_1)来解释随温度变化的光谱，这两种运动都随着温度的升高而变快。具体地说，在较高的温度下，R_1和R_2的速率都足够快，足以平均磁各向异性。随着温度的降低，R_1的速度变慢，在200K附近基本被冻结，而R_2的速度很快，在120K以上可以平均出g_1-g_2各向异性，但在40K以上仍然很快地产生额外的各向异性峰。

项目成果

T.Ohya: "Comparative Study of Moessbauer Spectra of Iron (III) Complexes of para-Substituted Tetraphenylporphyrins. Electronic Effects of Substituents and Axial Ligands" J.Chem.Soc.,Dalton Trans.,. 1519-1523 (1996)

T.Ohya：“对位取代的四苯基卟啉铁 (III) 配合物的穆斯堡尔谱的比较研究。取代基和轴向配体的电子效应”J.Chem.Soc.，Dalton Trans.，。

T.Ohya: "Comparative Study of Moesbauer Spectra of Iron (III) Complexes of para-Substituted Tetraphenylporpjyrins. Electronic Effects of Substituents and Axial Ligands" J.Chem.Soc.,Dalton Trans.,. 1519-1523 (1996)

T.Ohya：“对位取代的四苯基卟啉铁 (III) 络合物的 Moesbauer 光谱的比较研究。取代基和轴向配体的电子效应”J.Chem.Soc.，Dalton Trans.,。

T.Senda, K.Sugiyama, H.Narita, T.Yamamoto, K.Kimbara, M.Fukuda, M.Sato, K.Yano, and Y.Mitsui: "Three-Dimensional Structures of Free Form and Two Substrate Complexes of Extradiol Ring-Cleavage Type Dioxygenase, the BphC Enzyme from Pseudomonas sp. Strain K

T.Senda、K.Sugiyama、H.Narita、T.Yamamoto、K.Kimbara、M.Fukuda、M.Sato、K.Yano 和 Y.Mitsui：“自由形式的三维结构和两种基质复合物

T.Ohya, and M.Sato: "Comparative Study of Moesbauer Spectra of Iron (III) Complexes of para-Substituted Tetraphenylporphyrins. Electronic Effects of Substituents and Axial Ligands" J.Chem.Soc., Dalton Trans.1519-1523 (1996)

T.Ohya 和 M.Sato：“对位取代的四苯基卟啉铁 (III) 络合物的 Moesbauer 光谱的比较研究。取代基和轴向配体的电子效应”J.Chem.Soc.，Dalton Trans.1519-1523 (1996)

T.Ohya: "Comparative Study of Visible Spectra of Iron (III) COmplexes of para-Substituted Tetraphenylporphyrins, Electronic Effects of Substituents and Axial Ligands" Bull.Chem.Soc.Jpn.,. 69. 3201-3205 (1996)

T.Ohya：“对位取代的四苯基卟啉的铁 (III) 络合物的可见光谱、取代基和轴向配体的电子效应的比较研究”Bull.Chem.Soc.Jpn.,。