Fig. 1. Variation of ion intensity with respect to the pressures of CO on the reactions of CuC₃H⁻ (a), CuC₃D⁻ (b), and CuC₃⁻ (c) with CO. The data points were experimentally measured, and the solid lines were fitted to the experimental data points on the basis of least-square procedure. The fitted results demonstrated that about 31% of laser-ablation generated CuC₃H⁻ and about 37% of such generated CuC₃D⁻ were inert toward CO.

Fig. 1. Time-of-flight mass spectra for the reactions of mass-selected CuC₃H\begin{document}$ ^- $\end{document}, CuC₃D\begin{document}$ ^- $\end{document}, and CuC₃\begin{document}$ ^- $\end{document} anions with He (A, D, and F) and CO (B, C, E, and G). The reaction time is about 1.3 ms for CuC₃H\begin{document}$ ^- $\end{document}+CO and CuC₃D\begin{document}$ ^- $\end{document}+CO, and 2.3 ms for CuC₃\begin{document}$ ^- $\end{document}+CO.

Fig. 2. (A) The DFT-calculated low-lying isomers for CuC₃H\begin{document}$ ^- $\end{document}. Single point energies calculated at the CCSD(T) level are listed in the square brackets. The relative energies are given in eV. M2 and M4 represent the doublet and the quartet electronic states, respectively. (B) Potential energy profile for internal conversion among different CuC₃H\begin{document}$ ^- $\end{document} isomers, and details can be found in FIG. S3 in the supplementary materials.

Fig. 2. The density functional theory (DFT) calculated structures and relative energies of the CuC₃H⁻ and CuC₃⁻ isomers as well as the structures of products COC₃H⁻ and COC₃⁻. The relative energies are in unit of eV and bond lengths are given in pm. Single point energies calculated at the CCSD(T) level are listed in the square brackets.

Fig. 3. Photoelectron spectra of CuC₃H\begin{document}$ ^- $\end{document} measured with (A) 520, 700, and 380 nm photons at 298 K and (B) 520 and 880 nm photons at 10 K, respectively. The simulated Franck-Condon (FC) spectra for the low-lying CuC₃H\begin{document}$ ^- $\end{document} isomers are shown in panels (C-F). The calculated vertical electron detachment energies for each isomer are listed in the square brackets.

Fig. 3. The DFT-calculated profiles on the transformation of different CuC₃H⁻ isomers shown in FIG. S2. The relative energies are in unit of eV and bond lengths are shown in pm. The superscripts "2" and "4" represent the doublet and the quartet electronic states, respectively.

Fig. 4. The DFT-calculated potential energy profiles for reactions (A) CuC₃H\begin{document}$ ^- $\end{document}(IS1)+CO on the doublet state and (B) CuC₃\begin{document}$ ^- $\end{document}+CO on both of the singlet and the triplet states. The zero-point vibration corrected energies (\begin{document}$ \Delta H_0 $\end{document}, eV) are given. Bond lengths are given in pm.

Fig. 4. The DFT calculated potential energy profile for reaction CuC₃H⁻ + CO on the doublet state. The relative energies are in unit of eV. The structures of intermediates and transition states are plotted. Bond lengths are given in pm.

Fig. 5. Natural charge in e distributions on I3, I5, \begin{document}$ ^3 $\end{document}I6, and \begin{document}$ ^1 $\end{document}I7. The blue values indicate the natural charges.

Fig. 5. The DFT-calculated potential energy profiles on the reactions of lower-lying CuC₃H⁻ isomers with CO. The relative energies are in unit of eV and the bond lengths are given in pm. The structures of intermediates and transition states are plotted.

Fig. 6. (A) Spin crossing from the triplet state to the singlet state. The curve for the triplet state is from the intrinsic reaction coordinate (IRC) calculations. The energies of the singlet states are calculated at the IRC determined triplet state structures. (B) Spin crossing from the quartet state to the doublet state. The curve for the quartet state is from the Scan calculation. The energies of the doublet states are calculated at the Scan determined quartet state structures.