Blagojevic Voislav, Blagojevic Vladimir A, Koyanagi Gregory K, Bohme Diethard K
BrightSpec, Inc., Charlottesville, Virginia 22903, United States.
TBP Soft, Belgrade 11000, Serbia.
J Am Soc Mass Spectrom. 2022 Aug 3;33(8):1419-1426. doi: 10.1021/jasms.2c00075. Epub 2022 May 9.
The interaction of the atomic coinage metal cations Cu, Ag, and Au with O, a weak ligand, and CH, a strong ligand, was investigated with measurements of rate coefficients of ligation and quantum-chemical computations of ligation energies with an eye on relativistic effects going down the periodic table. Strong "third row enhancements" were observed for both the rate coefficients of ligation and ligation energies with the O ligand and for the formation of both the mono- and bis-adducts of M and the monoadduct of M(CH). The computations revealed that the third-row enhancement in the ligation energy is attributable to a relativistic increase in the ligation energy. This means that rate coefficient measurements down the periodic table for the ligation of coinage metal cations with O provide a probe of the relativistic effect in ligation reactions, as expected from the known dependence of the rate coefficient of ligation on the ligation energy. The much stronger benzene ligand was observed to ligate the atomic coinage metal cations with nearly 100% efficiency so that there is no, or only slightly, visible third-row enhancement despite the strong relativistic effect in the binding energy that is revealed by the calculations. Relativistic effects contribute substantially to the extraordinary stability against deligation of all the observed mono- and bis-adducts of Au relative to Ag, truly a "third-row enhancement".
通过配位反应速率系数的测量以及配位能的量子化学计算，研究了原子态的铜族金属阳离子Cu、Ag和Au与弱配体O以及强配体CH之间的相互作用，重点关注元素周期表中同族元素的相对论效应。对于与O配体的配位反应速率系数和配位能，以及M的单加合物和双加合物与M(CH)单加合物的形成，均观察到了强烈的“第三周期增强”现象。计算结果表明，配位能的第三周期增强归因于配位能的相对论性增加。这意味着，正如已知的配位反应速率系数对配位能的依赖性所预期的那样，对铜族金属阳离子与O的配位反应在元素周期表中的速率系数测量提供了一种探测配位反应中相对论效应的方法。观察到更强的苯配体以近100%的效率与原子态的铜族金属阳离子配位，因此尽管计算结果表明结合能中存在强烈的相对论效应，但未观察到明显的第三周期增强，或仅有轻微的增强。相对论效应极大地促进了相对于Ag而言，所有观察到的Au的单加合物和双加合物对解配具有非凡的稳定性，这确实是一种“第三周期增强”。
