Jahn-Teller distortion and dissociation of CCl 4 + by transient X-ray spectroscopy simultaneously at the carbon K- and chlorine L-edge.
Andrew D RossDiptarka HaitValeriu ScutelnicEric A HaugenEnrico RidenteMikias B BalkewDaniel M NeumarkMartin Head-GordonStephen R LeonePublished in: Chemical science (2022)
X-ray Transient Absorption Spectroscopy (XTAS) and theoretical calculations are used to study CCl 4 + prepared by 800 nm strong-field ionization. XTAS simultaneously probes atoms at the carbon K-edge (280-300 eV) and chlorine L-edge (195-220 eV). Comparison of experiment to X-ray spectra computed by orbital-optimized density functional theory (OO-DFT) indicates that after ionization, CCl 4 + undergoes symmetry breaking driven by Jahn-Teller distortion away from the initial tetrahedral structure (T d ) in 6 ± 2 fs. The resultant symmetry-broken covalently bonded form subsequently separates to a noncovalently bound complex between CCl 3 + and Cl over 90 ± 10 fs, which is again predicted by theory. Finally, after more than 800 fs, L-edge signals for atomic Cl are observed, indicating dissociation to free CCl 3 + and Cl. The results for Jahn-Teller distortion to the symmetry-broken form of CCl 4 + and formation of the Cl-CCl + 3 complex characterize previously unobserved new species along the route to dissociation.