Reaction of a superoxochromium(III) ion with nitrogen monoxide: kinetics and mechanism.
Reaction of a superoxochromium(III) ion with nitrogen monoxide: kinetics and mechanism.
复制标题
超氧铬（III）离子与一氧化氮的反应：动力学和机理。
DOI：
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发表时间：
2002
影响因子：
15
通讯作者：
A. Bakac
中科院分区：
文献类型：
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作者：
A. Nemes;Oleg Pestovsky;A. Bakac
通过激光闪光光解Cr（aq）NO（2+），测定了Cr（aq）OO（2+）和NO之间的快速反应动力学，在25 ℃时，K = 7 × 10（8）M（-1）s（-1）。反应产生一个中间体，被认为是NO（2），它被（[14]aneN（4））Ni（2+）清除。在限制NO的情况下，Cr（aq）OO（2+）/NO反应具有1：1的化学计量，并且产生游离NO（3）（-）和铬硝酸根络合物Cr（aq）ONO（2）（2+）。在过量NO的存在下，化学计量变为[NO]/[Cr（aq）OO（2+）] = 3：1，并且反应产生接近3摩尔亚硝酸根/摩尔Cr（aq）OO（2+）。一种中间体，被鉴定为亚硝酸铬（III）离子，Cr（aq）ONO（2+），是一部分游离NO（2）（-）的前体。在所提出的机理中，最初产生的过氧亚硝基络合物，Cr（aq）OONO（2+），经历O-O键均裂，然后是一些已知的和一些新的Cr（aq）O（2+）和NO（2）的化学反应。Cr（aq）O（2+）与NO反应生成Cr（aq）ONO（2+），k > 10（4）M（-1）s（-1）。Cr（aq）OO（2+）与NO（2）反应，k = 2.3 × 10（8）M（-1）s（-1）。
The kinetics of the rapid reaction between Cr(aq)OO(2+) and NO were determined by laser flash photolysis of Cr(aq)NO(2+) in O(2)-saturated acidic aqueous solutions, k = 7 x 10(8) M(-1) s(-1) at 25 degrees C. The reaction produces an intermediate, believed to be NO(2), which was scavenged with ([14]aneN(4))Ni(2+). With limiting NO, the Cr(aq)OO(2+)/NO reaction has a 1:1 stoichiometry and produces both free NO(3)(-) and a chromium nitrato complex, Cr(aq)ONO(2)(2+). In the presence of excess NO, the stoichiometry changes to [NO]/[Cr(aq)OO(2+)] = 3:1, and the reaction produces close to 3 mol of nitrite/mol of Cr(aq)OO(2+). An intermediate, identified as a nitritochromium(III) ion, Cr(aq)ONO(2+), is a precursor to a portion of free NO(2)(-). In the proposed mechanism, the initially produced peroxynitrito complex, Cr(aq)OONO(2+), undergoes O-O bond homolysis followed by some known and some novel chemistry of Cr(aq)O(2+) and NO(2). The reaction between Cr(aq)O(2+) and NO generates Cr(aq)ONO(2+), k > 10(4) M(-1) s(-1). Cr(aq)OO(2+) reacts with NO(2) with k = 2.3 x 10(8) M(-1) s(-1).