Ultrafast Dissociation of Metastable CO2+ in a Dimer

Abstract

We triply ionize the van der Waals bound carbon monoxide dimer with intense ultrashort pulses and study the breakup channel (CO)_{2}^{3+}→C^{+}+O^{+}+CO^{+}. The fragments are recorded in a cold target recoil ion momentum spectrometer. We observe a fast CO^{2+} dissociation channel in the dimer, which does not exist for the monomer. We found that a nearby charge breaks the symmetry of a X^{3}Π state of CO^{2+} and induces an avoided crossing that allows a fast dissociation. Calculation on the full dimer complex shows the coupling of different charge states, as predicted from excimer theory, gives rise to electronic state components not present in the monomer, thereby enabling fast dissociation with higher kinetic energy release. These results demonstrate that the electronic structure of molecular cluster complexes can give rise to dynamics that is qualitatively different from that observed in the component monomers.

Role of a Neighbor Ion in the Fragmentation Dynamics of Covalent Molecules

“…Note added.-Recently, results on the three-body fragmentation of CO dimers induced by intense ultrashort laser pulses were published [26]. Similar shifts of the KER spectra are reported and the appearance of an exotic fast dissociation channel of the CO 2þ dication is observed.…”

Laser-Induced Electron Transfer in the Dissociative Multiple Ionization of Argon Dimers

“…vdW dimers are used to study photoinduced biological processes [12][13][14], photocatalytic reactions [15,16], and energy or charge transfer reactions induced by soft x-ray photons [17][18][19][20] and electron impact [21]. vdW systems are also studied with strong laser fields, but in the case of dimers with a focus on the field-driven ionization and fragmentation dynamics [22][23][24][25][26][27][28][29][30][31][32][33][34][35], or electronic energy conversion processes in the case of larger clusters [36][37][38][39][40][41]. To the best of our knowledge, strong-field driven electron transfer reactions across the system boundary from one entity to another have not been investigated, thus far.…”

Native Frames: Disentangling Sequential from Concerted Three-Body Fragmentation

“…Advances in imaging techniques have led to better understanding of molecular fragmentation [1][2][3][4][5][6]. Experimentally distinguishing between concerted and sequential (sometimes called stepwise) fragmentation mechanisms in polyatomic molecules is a long-standing goal of these efforts (see, for example, [3,5,[7][8][9][10][11][12][13][14][15][16][17]). Key to its achievement is the coincidence detection of all fragments, although alternatives without coincidence measurements have been suggested [7].…”

“…Key to its achievement is the coincidence detection of all fragments, although alternatives without coincidence measurements have been suggested [7]. In recent years, coincidence momentum imaging techniques have progressed significantly toward this goal [5,[10][11][12][13][14][15][16][17].…”