Unraveling the Metastability of Cn 2+ (n = 2-4) Clusters

Peng, Z. and Zanuttini, D. and Gervais, B. and Jacquet, E. and Blum, I. and Choi, P.-P. and Raabe, D. and Vurpillot, F. and Gault, B.

Volume: 10 Pages: 581-588
DOI: 10.1021/acs.jpclett.8b03449
Published: 2019

Pure carbon clusters have received considerable attention for a long time. However, fundamental questions, such as what the smallest stable carbon cluster dication is, remain unclear. We investigated the stability and fragmentation behavior of Cn 2+ (n = 2-4) dications using state-of-the-art atom probe tomography. These small doubly charged carbon cluster ions were produced by laser-pulsed field evaporation from a tungsten carbide field emitter. Correlation analysis of the fragments detected in coincidence reveals that they only decay to Cn-1 + + C+. During C2 2+ ? C+ + C+, significant kinetic energy release (5.75-7.8 eV) is evidenced. Through advanced experimental data processing combined with ab initio calculations and simulations, we show that the field-evaporated diatomic 12C2 2+ dications are either in weakly bound 3?u and 3Sg - states, quickly dissociating under the intense electric field, or in a deeply bound electronic 5Su - state with lifetimes >180 ps. © Copyright © 2019 American Chemical Society.

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