High resolution spectroscopy for the (A)over-tilde 2A1 state of CH3I+ by mass-analyzed threshold ionization/photodissociation

Photodissociation of CH3I+ in the ground vibronic state generated by mass-analyzed threshold ionization resulted in a superb spectrum for the first excited electronic state (A (2)A(1)) with hardly any spurious peak. Rotational structure in the spectrum could be resolved by using a single mode laser. This structure for one vibronic band, 2(1)3(1)6(1), was analyzed with the assumption of Hund's case (a) scheme both in the ground and excited electronic states. (C) 2007 American Institute of Physics.