MN-55 ESE-ENDOR OF A MIXED-VALENCE MN(III)MN(IV) COMPLEX - COMPARISON WITH THE MN CLUSTER OF THE PHOTOSYNTHETIC OXYGEN-EVOLVING COMPLEX
MN-55 ESE-ENDOR OF A MIXED-VALENCE MN(III)MN(IV) COMPLEX - COMPARISON WITH THE MN CLUSTER OF THE PHOTOSYNTHETIC OXYGEN-EVOLVING COMPLEX
复制标题
DOI：
10.1021/ja00152a021
复制
发表时间：
1995-11-29
影响因子：
15
通讯作者：
BRITT, RD
中科院分区：
文献类型：
--
作者：
RANDALL, DW;STURGEON, BE;BRITT, RD
对双核混合价态Mn(III)Mn（IV）配合物[二-mu-氧四元（2,2′-联吡啶）二锰（III，IV）]上获得的Mn-55电子自旋回声-电子核双共振（es - endor）谱分析(1)揭示了Mn（III）和Mn（IV）离子自旋I = 5/2 Mn-55核的超精细和核四极参数。得到如下参数：对于Mn(IV)， A（垂直于）= +212 MHz， A（平行于）= +231 MHz， p -平行于3e(2)Qq/40 = +2.0 MHz, eta = 0.3；对于Mn(III)， A垂直于= -480 MHz， A（平行于）-360 MHz， p -平行于= -4.5 MHz, eta = 0.1。在光系统II的S-2态的g = 2 Mn多线EPR信号上获得的Mn-55 esi - endor数据表明，该EPR信号不可能来自双核Mn(III)Mn（IV）中心。ENDOR光谱与光系统II多线EPR信号的四核Mn簇起源一致。
Analysis of Mn-55 electron spin echo-electron nuclear double resonance (ESE-ENDOR) spectra obtained on a dinuclear mixed valence Mn(III)Mn(IV) complex [di-mu-oxotetrakis(2,2'-bipyridine)dimanganese(III,IV)] (1) reveals the hyperfine and nuclear quadrupolar parameters for the spin I = 5/2 Mn-55 nucleus of both Mn(III) and Mn(IV) ions. The following parameters are obtained: for Mn(IV), A(perpendicular to) = +212 MHz, A(parallel to) = +231 MHz, P-parallel to 3e(2)Qq/40 = +2.0 MHz, and eta = 0.3, and for Mn(III), A perpendicular to = -480 MHz, A(parallel to) -360 MHz, P-parallel to = -4.5 MHz, and eta = 0.1. The Mn-55 ESE-ENDOR data obtained on the g = 2 Mn multiline EPR signal of the S-2 state of the photosystem II oxygen-evolving complex demonstrate that this EPR signal cannot arise from a dinuclear Mn(III)Mn(IV) center. The ENDOR spectra are consistent with a tetranuclear Mn cluster origin for the photosystem II multiline EPR signal.