Chemical Physics Letters, Vol.329, No.1-2, 29-35, 2000
Rotationally resolved A (2)Pi(u)<- X (2)Pi(g) electronic spectrum of tetraacetylene cation
The rotationally resolved A (2)Pi (u) <-- X (2)(g) electronic origin band spectrum of tetraacetylene cation (HC8H+) and its deuterated derivative (DC8D+) has been recorded in the gas phase, applying both frequency modulation spectroscopy in a liquid nitrogen cooled hollow cathode discharge and cavity ringdown spectroscopy in a supersonic planar plasma. The combined analysis of the rotational structure yields accurate molecular constants for the ground and electronically excited states as well as information on the molecular geometry.