Oxygen Atom Transfer from a trans-Dioxoruthenium(VI) Complex to Nitric Oxide
Oxygen Atom Transfer from a trans-Dioxoruthenium(VI) Complex to Nitric Oxide
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DOI：
10.1002/chem.201102297
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发表时间：
2012-01-01
影响因子：
4.3
通讯作者：
Lau, Tai-Chu
中科院分区：
文献类型：
--
作者：
Man, Wai-Lun;Lam, William W. Y.;Lau, Tai-Chu
In aqueous acidic solutions trans-[RuVI(L)(O)2]2+ (L=1,12-dimethyl-3,4:9,10-dibenzo-1,12-diaza-5,8-dioxacyclopentadecane) is rapidly reduced by excess NO to give trans-[Ru(L)(NO)(OH)]2+. When =1 mol equiv NO is used, the intermediate RuIV species, trans-[RuIV(L)(O)(OH2)]2+, can be detected. The reaction of [RuVI(L)(O)2]2+ with NO is first order with respect to [RuVI] and [NO], k2=(4.13 +/- 0.21)x101M-1s-1 at 298.0 K. ?H? and ?S? are (12.0 +/- 0.3) kcal?mol-1 and -(11 +/- 1) cal?mol-1?K-1, respectively. In CH3CN, ?H? and ?S? have the same values as in H2O; this suggests that the mechanism is the same in both solvents. In CH3CN, the reaction of [RuVI(L)(O)2]2+ with NO produces a blue-green species with ?max at approximately 650 nm, which is characteristic of N2O3. N2O3 is formed by coupling of NO2 with excess NO; it is relatively stable in CH3CN, but undergoes rapid hydrolysis in H2O. A mechanism that involves oxygen atom transfer from [RuVI(L)(O)2]2+ to NO to produce NO2 is proposed. The kinetics of the reaction of [RuIV(L)(O)(OH2)]2+ with NO has also been investigated. In this case, the data are consistent with initial one-electron O- transfer from RuIV to NO to produce the nitrito species [RuIII(L)(ONO)(OH2)]2+ (k2>106?M-1?s-1), followed by a reaction with another molecule of NO to give [Ru(L)(NO)(OH)]2+ and NO2- (k2=54.7?M-1?s-1).
