Comment on “Gas-phase ion-molecule interactions in a collision reaction cell with triple quadrupole-inductively coupled plasma mass spectrometry: Investigations with N2O as the reaction gas” by Khadouja Harouaka, Caleb Allen, Eric Bylaska, Richard M Cox,
Comment on “Gas-phase ion-molecule interactions in a collision reaction cell with triple quadrupole-inductively coupled plasma mass spectrometry: Investigations with N2O as the reaction gas” by Khadouja Harouaka, Caleb Allen, Eric Bylaska, Richard M Cox,
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Khadouja Harouaka、Caleb Allen、Eric Bylaska、Richard M Cox 评论“采用三重四极杆电感耦合等离子体质谱的碰撞反应池中的气相离子-分子相互作用：以 N2O 作为反应气体的研究”，
DOI：
10.1016/j.sab.2021.106345
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Armentrout, P.B.
中科院分区：
文献类型：
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作者：
Armentrout, P.B.
M+，m+ O2 3→ MO+，m+ O3（1）其中M+和MO+代表元素阳离子和氧化物阳离子，m是它们的多重数，此处添加了分子和原子氧的三重态多重数。他们指出，所写的这个反应隐含地假设自旋是守恒的。这个陈述显然是假设，因为O2和O都是三重态，那么自旋守恒意味着M+和MO+的自旋态必须相同。这个结论是不正确的。回想三重态自旋态明确地指简并自旋态（αα）、（αβ+ βα）和（ββ），可以认识到这些态与具有多重性m的物质的相互作用将沿着具有（m+ 2）、（m）和（m-2）自旋的表面演化。例如，五重态物质与O2（总简并度为5× 3= 15）的反应将产生七重态（m= 7）、五重态（m= 5）和三重态（m= 3）自旋的表面（总简并度为7+ 5+ 3= 15）。所有这些表面都是自旋守恒的，变化只在于两个反应物上的未成对电子是否单重态耦合。产物也是如此，因此具有七重态自旋的反应表面可以演化形成n= 9、7和5的MO+、n+ O3产物，具有五重态自旋的表面可以具有n= 7、5和3，三重态自旋表面可以导致n= 5、3和1的产物。因此，描述所有保持自旋的反应的正确关系式是：
M+, m+ O2 3→ MO+, m+ O3(1) where M+ and MO+ represent the elemental and oxide cations, and m is their multiplicity, with the triplet multiplicity of molecular and atomic oxygen added here. They state that this reaction as written implicitly assumes that the spin is conserved. This statement apparently presumes that because O2 and O are both triplets, then spin conservation implies that the spin states of M+ and MO+ must be the same. This conclusion is incorrect. Recalling that the triplet spin state refers explicitly to the degenerate spin states (αα),(αβ+ βα), and (ββ), it can be realized that the interaction of these states with a species having multiplicity m will evolve along surfaces having spins of (m+ 2),(m), and (m-2). For example, reaction of a quintet species with O2 (total degeneracy of 5× 3= 15) will generate surfaces of septet (m= 7), quintet (m= 5), and triplet (m= 3) spin (total degeneracy of 7+ 5+ 3= 15). All of these surfaces conserve spin and vary only in whether unpaired electrons on the two reactants singlet couple or not. The same is true for the products, hence the reaction surface having septet spin can evolve to form MO+, n+ O3 products with n= 9, 7, and 5, the surface with quintet spin can have n= 7, 5, and 3, and the triplet spin surface can lead to products with n= 5, 3, and 1. Therefore, the correct relationship that describes all reactions that conserve spin is