Pulse-radiolysis study of mixed-valence MoIV,V complexes of EDTA, L-cysteine, and oxalate
Pulse-radiolysis study of mixed-valence MoIV,V complexes of EDTA, L-cysteine, and oxalate
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EDTA、L-半胱氨酸和草酸盐混合价 MoIV、V 复合物的脉冲放射分解研究
DOI：
10.1021/ic00217a040
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
B. Bielski
中科院分区：
文献类型：
--
作者：
J. Rush;B. Bielski
通过脉冲辐解还原Mo/supV/O/sub 4/L/sub n//sup 2 -/，得到了Mo/supV/O/sub 4/L/sub n//sup 2 -/，其中L/sub n/ =（EDTA），（L-cyst）/sub 2/，或（ox）/sub 2/（H/sub 2/O）/sub 2/.发现各种复合物的还原速率相似; k/sub 4/ = k/sub 5/ =（1.5 +/- 0.5）x 10/sup 10/ M/sup-1/S/sup-1/。混合价配合物也可以通过用Zn/sup +/（k/sub 6/ approx. k/sub 7/约= 5 x 10/sup 9/ M/sup -1/ S/sup -1/）。Mo（IV，V）混合价络合物在可见光范围内吸收较弱（约100 nm）。300-500 M/sup-1/ cm/sup-1/）。而在没有氧气的情况下，它们的衰变相对缓慢（t/sub 1/2/ approx. 5-10 s），并且不会导致Mo（III）产物的形成，在O/sub 2/的存在下，它们经历快速的二级氧化（k约为0.001）。10/sup 8/ M/sup-1/ s/sup-9/回到Mo（V）络合物。后一观察结果表明，Mo/sup V//sub 2/O/sub 4//sup 2 +/单元再生的驱动力足以导致还原络合物中配体的还原。用硫化物取代EDTA络合物中的桥接氧化物不会显著改变混合价络合物的稳定性。参考文献18篇，附图3幅。«少
The molybdenum(IV,V) mixed-valence complexes Mo/sup IV/Mo/sup V/O/sub 4/L/sub n//sup 2 -/, where L/sub n/ = (EDTA), (L-cyst)/sub 2/, or (ox)/sub 2/(H/sub 2/O)/sub 2/, were obtained by pulse-radiolytic reduction of the corresponding Mo/sup V/ complexes with the hydrated electron, e/sub aq//sup -/. The rates of reduction for the various complexes were found to be similar; k/sub 4/ = k/sub 5/ = (1.5 +/- 0.5) x 10/sup 10/ M/sup -1/S/sup -1/. The mixed-valence complexes can also be generated by reduction of the parent complexes with Zn/sup +/ (k/sub 6/ approx. k/sub 7/ approx. = 5 x 10/sup 9/ M/sup -1/ S/sup -1/). The Mo(IV,V) mixed-valence complexes absorb weakly in the visible range (epsilon approx. 300-500 M/sup -1/ cm/sup -1/). While in the absence of oxygen their decay is relatively slow (t/sub 1/2/ approx. 5-10 s) and does not result in Mo(III) product formation, in the presence of O/sub 2/ they undergo rapid second-order oxidation (k approx. 10/sup 8/ M/sup -1/ s/sup -9/ back to the Mo(V) complexes. The latter observation suggests that the driving force for regeneration of the Mo/sup V//sub 2/O/sub 4//sup 2 +/ unit is sufficient to cause reduction of the ligands in the reduced complex. Substitution of the bridgingmore » oxides in the EDTA complex with sulfide does not significantly change the stability of the mixed-valence complex. 18 references, 3 figures.« less