A photoelectron–photoion coincidence study of H2O, D2O, and (H2O)2

Photoelectron–photoion coincidence (PEPICO) data for OH+(OD+), H+(D+), and H2O+ (D2O+) from H2O (D2O) have been obtained in the region of 625–700 A. The PEPICO measurements allow the construction of breakdown diagrams for the unimolecular dissociation of energy‐selected H2O+ and D2O+ in the B 2B2 state. The breakdown diagrams for H2O+(B 2B2) and D2O+(B 2B2) in the internal energy range of 129–166 kcal/mol are essentially identical. The branching ratios observed for H+ (D+) are higher than those reported previously. About 3%–5% of stable H2O+ (D2O+) is observed in the time scale of ≊10 μs. These stable H2O+ (D2O+) ions are attributed to ultrafast B 2B2→A2A1 nonradiative relaxation followed by the radiative stabilization from H2O+(A2A1) [D2O+(A2A1)] to H2O+ (X2B1) [D2O+(X2B1)]. This observation also supports that the formation of H+ (D+) via the H2O+ (A 2A1)[D2O+(A2A1)] state is a viable process. The relative state‐selected cross sections for the reaction H2O+ (X2B1,A2A1; ν1, ν2)+H2O→H3O+ +H at...

[1]  C. Ng.  Vacuum ultraviolet photoionization and photodissociation of molecules and clusters , 1991 .

[2]  C. Ng,et al.  A state‐selected study of the unimolecular decomposition of C2H+2(Ã,B̃) using the photoion–photoelectron coincidence method , 1989 .

[3]  C. Ng,et al.  Photoion-photoelectron coincidence spectroscopy of the transient molecules SO and S2O , 1989 .

[4]  C. Ng,et al.  A photoion–photoelectron coincidence study of Arn (n=2–4) , 1989 .

[5]  C. Ng,et al.  A Study of intramolecular charge transfer in mixed Ar/CO dimer and trimer ions using the photoion-photoelectron coincidence method , 1989 .

[6]  D. A. Shirley,et al.  Molecular beam photoelectron spectroscopy and femtosecond intramolecular dynamics of H2O+ and D2O+ , 1986 .

[7]  T. Baer,et al.  Autoionization and isotope effect in the threshold photoelectron spectrum of 12CO2 and 13CO2 , 1986 .

[8]  I. Nenner,et al.  Interactions between neutral dissociation and ionization continua in N2O , 1983 .

[9]  X. Chapuisat,et al.  Dynamical study of nonadiabatic unimolecular reactions: The conical intersection between the B̃ 2B2 and à 2A1 states of H2O+ , 1983 .

[10]  Y. Achiba,et al.  Photoelectron spectrum of the water dimer , 1982 .

[11]  S. Manson,et al.  Photoabsorption, Photoionization, and Photoelectron Spectroscopy , 1979 .

[12]  I. Nenner,et al.  Non‐Franck–Condon transitions in resonant autoionization of N2O , 1979 .

[13]  G. Möhlmann,et al.  Lifetimes of the vibronic Ã2A1 states of H2O+ and of the 3Πi (υ′ = 0) state of OH+ , 1978 .

[14]  J. Berkowitz,et al.  Photodissociative ionization in the 21–41 eV region: O2, N2, CO, NO, CO2, H2O, NH3 and CH4☆ , 1976 .

[15]  H. Lew.  Electronic spectrum of H2O , 1976 .

[16]  G. Duxbury,et al.  Ro-vibronic structure in the photoelectron spectra of H2O, D2O and HDO , 1976 .

[17]  J. Eland.  The predissociations of water ions , 1975 .

[18]  J. Brzozowski,et al.  Lifetimes of excited states in D2O+ and OD+ and relative lifetimes between the normal and deuterated species , 1975 .

[19]  R. G. Albridge,et al.  Isotopic and vibronic coupling effects in the valence electron spectra of H2 16O, H2 18O, and D2 16O , 1975 .

[20]  J. Lorquet,et al.  Excited states of gaseous ions. V. The predissociation of the h2o+ ion , 1974 .

[21]  G. Herzberg,et al.  Identification of H_{2}O in the Tail of Comet Kohoutek (1973f). , 1974 .

[22]  D. W. Turner,et al.  High resolution molecular photoelectron spectroscopy II. Water and deuterium oxide , 1968, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[23]  H. Rosenstock,et al.  Mass Spectrometric Study of Photoionization V. Water and Ammonia. , 1966, Journal of research of the National Bureau of Standards. Section A, Physics and chemistry.

[24]  F. Fiquet-Fayard,et al.  Préionisation et prédissociation dans la dissociation des molécules triatomiques par impact électronique , 1966 .