Guided Ion Beam and Theoretical Studies of the Reactions of Pd+ with CS2: Thermochemistry of PdS+ and PdCS+
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- 作者：P. B. Armentrout ; Ilona Kretzschmar
- 刊名：Inorganic Chemistry
- 出版年：2009
- 出版时间：November 2, 2009
- 年：2009
- 卷：48
- 期：21
- 页码：10371-10382
- 全文大小：994K
- 年卷期：v.48,no.21(November 2, 2009)
- ISSN：1520-510X
文摘
The gas-phase reactivity of the atomic palladium cation with CS2 is investigated using guided-ion beam mass spectrometry. Endothermic reactions forming PdS+ and PdCS+ are observed. Analysis of the kinetic energy dependence of the cross sections for formation of the two products yields the 0 K bond energies of D0(Pd+−S) = 2.36 ± 0.11 eV and D0(Pd+−CS) = 2.67 ± 0.21 eV. Quantum chemical calculations are used to investigate the electronic structure of the two product ions. In addition, detailed calculations of the potential energy surfaces reveal that the mechanism involves oxidative addition of a CS bond to the metal cation followed by simple bond cleavages. Formation of the ground-state PdS+ (4Σ−) product is spin-forbidden from ground-state Pd+ (2D) whereas PdCS+ (2Σ+) formation is spin-allowed. Crossing points between the doublet and quartet surfaces are located in the region of the SPd+(CS) intermediate, which suggests that coupling between the surfaces is efficient, consistent with experimental indications.