Electronic absorptions of C5+ detected in the visible through action spectroscopy in a cryogenic trap

Abstract

The (Formula presented.) electronic spectrum of C (Formula presented.) in the gas-phase with origin band at (Formula presented.) is reported following experiments in a cryogenic ion trapping instrument. Buffer gas-cooled C (Formula presented.) ions, generated by laser vaporisation of graphite, were investigated using two action spectroscopy approaches. Laser-induced dissociation of weakly bound (Formula presented.) complexes synthesised in the trap reveal a linear dependence of the absorption energies on n allowing prediction of those of the bare ion C (Formula presented.). These results are confirmed in two colour experiments on C (Formula presented.), by monitoring fragmentation into the (Formula presented.) product channel. The data are supplemented with high-level electronic structure calculations which support the assignment of (Formula presented.) symmetry to the ground electronic state. These laboratory results provide the requisite data needed for spectroscopic detection of this structure in terrestrial and extraterrestrial environments.