Multiphoton dissociation of ions derived from 2-propanol in a QUISTOR with low-power CW infrared laser radiation

Abstract

We here report multiphoton dissociation of gas-phase ions derived from 2-propanol, using low-intensity infrared CO 2 laser radiation at 944 cm −1 A quadrupole ion store (QUISTOR) was used to store ions, which were then irradiated for up to 100 ms at a laser intensity of ∼80 W cm −2. The unfocused laser beam was allowed to pass radially through the ring electrode of the QUISTOR. At 4 × 10 −5 torr, the protonated dimer of 2-propanol was photodissociated to the extent of ∼25% in 50 ms, which constitutes evidence strongly supportive of collisional focusing of ions at the center of the QUISTOR. An assumed first-order dissociative rate constant was measured using a pulsed mode wherein the accumulation of protonated dimer was followed by resonance ejection of the precursor ion species, protonated 2-propanol, with concomitant laser irradiation.