Two-photon photoacoustic spectroscopy of acetone 3p Rydberg states

Vibronic coupling in excited states of acetone

“…This would be in line with previous suspicions that the 3p y state is subject to vibronic coupling with the valence excited *( 1 A 1 ) state. Photoacoustic measurements 28,29 give ample reason to believe that this * state has a very short lifetime, and its mixing with the 3 p y state would thus lead to a shortening of the lifetime of this state-in agreement with our observations. Although our photoelectron spectra do not exhibit any direct signature of this 3p y -* vibronic coupling, we can conclude that the excitation spectra indirectly give evidence for its presence.…”

“…24,27 The comparison of the one-photon absorption spectrum with the twophoton resonance enhanced multiphoton ionization ͑REMPI͒ spectrum under linearly and circularly polarized excitation light conditions ultimately enabled the unambiguous assignment of the origin transitions found at 7.36, 7.41, and 7.45 eV as deriving from the 3p x , 3p y , and 3p z states, respectively. 11,24,27,28 Photoacoustic spectroscopy 28 demonstrated dramatic differences in the radiationless decay channels available to the three Rydberg states. In particular the 3 p y Rydberg state was considered to be subject to considerable mixing with the * ( 1 A 1 ) valence excited state, 29 although for the 3p z Rydberg state some mixing with an n* valence excited state was invoked as well.…”

“…In particular the 3 p y Rydberg state was considered to be subject to considerable mixing with the * ( 1 A 1 ) valence excited state, 29 although for the 3p z Rydberg state some mixing with an n* valence excited state was invoked as well. 28 Subsequent extensive studies of the two-and three-photon excitation spectra of the 3 p Rydberg states and their polarization dependence led to assignments of active vibrations in the excitation spectrum. 7,11,27 In these excitation spectra anomaa͒ Author to whom correspondence should be addressed.…”

A multiphoton ionization study of acetone using time-of-flight mass spectrometry

“…The lowest energy transition from the ground state to the 1 A 2 (n y →π * ) [1,2], the transition to the 3s ( 1 B 2 ) Rydberg state [3][4][5][6], and those to the three 3p Rydberg states have been observed [7][8][9][10][11][12][13][14][15]. The 3p x ( 1 A 2 ), 3p y ( 1 A 1 ), and 3p z ( 1 B 2 ) Rydberg states of acetone are positioned at 7.36, 7.41, and 7.45 eV, respectively [9,10,12,14,15]. The 3p Rydberg spectrum of acetone differs from that of the 3s Rydberg state, as the absorption in the 3p region is very weak and the zero point isotopic shift between the assigned origin bands of acetone and acetone-d 6 is small.…”

“…Acetone is the simplest aliphatic ketone and has been broadly studied due to its importance in many areas of chemistry. The electronic spectrum of acetone (in C 2v ) is established by transitions from the ground state ( 1 A 1 ) to the valence states (n y →π * , π→π * , σ→π*) and to some Rydberg states [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The low-energy transitions are well characterized.…”