Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
J Chem Phys. 2010 Mar 21;132(11):114307. doi: 10.1063/1.3360309.
The A (2)Pi(u)-X (2)Pi(g) band systems of jet-cooled (12)CO(2)(+) and (13)CO(2)(+) have been recorded by laser-induced fluorescence (LIF) techniques. Very intense, vibrationally cold expansions of these cations have been obtained using a pulsed electric discharge jet with a precursor mixture of carbon dioxide or (13)C labeled CO(2) in high pressure argon. The LIF bands have been partially rotationally analyzed to obtain band origins which yielded an accurate measure of the excited state vibronic energy levels. The energy levels of both isotopologues were fitted with a Renner-Teller model that included spin-orbit coupling, Fermi resonance and anharmonic terms. Single vibronic level emission spectra were also recorded for the (13)CO(2)(+) ion and the ground state energy levels fitted using the same Renner-Teller model. The isotope relations have been used to test the validity of the derived parameters. The results give a through description of the vibronic energy levels in the ground and first excited electronic states of the carbon dioxide cation.
采用激光诱导荧光（LIF）技术记录了喷射冷却的（12）CO(2)(+)和（13）CO(2)(+)的 A (2)Pi(u)-X (2)Pi(g) 带系。通过使用前驱体混合物为二氧化碳或（13）C 标记的 CO(2)的高压氩气中的脉冲放电喷射器，获得了这些阳离子的非常强烈且振动冷却的扩展。对 LIF 带进行了部分旋转分析，以获得带的起源，从而准确测量了激发态振动态能级。用包括自旋轨道耦合、费米共振和非谐项的 Renner-Teller 模型拟合了两种同位素的能级。还记录了（13）CO(2)(+)离子的单振动态发射光谱，并使用相同的 Renner-Teller 模型拟合了基态能级。同位素关系用于检验推导参数的有效性。结果全面描述了二氧化碳阳离子基态和第一激发电子态的振动态能级。
