A combined zero electronic kinetic energy spectroscopy and ion-pair dissociation imaging study of the F-2(+)(X (2)Pi(g)) structure

摘要

Rotationally resolved pulsed field ionization and zero electronic kinetic energy photoelectron spectra for the transition F-2(+)(X (2)Pi(g))<- F-2(X (1)Sigma(g)(+)) have been recorded using the extreme ultraviolet coherence radiation. The vibrational energy spacings, rotational constants, and spin orbit coupling constants for the first three vibrational states of F-2(+)(X (2)Pi(g)) have been determined accurately. The first adiabatic ionization potential (IP) of F-2 is determined as IP(F-2)=126 585.7 +/- 0.5 cm(-1). To determine the threshold E-tipp for ion-pair production of F-2, the images of F-(S-1(0)) in the velocity mapping conditions have also been recorded at the photon energy of 126 751 cm(-1). Taking the Stark effect into account, the E-tipp is determined as E-tipp(F-2)=126 045 +/- 8 cm(-1) (15.628 +/- 0.001 eV). By combing the IP(F-2) and the E-tipp(F-2) determined in this work and together with the reported ionization potential and electronic affinity of the F atom, the bond dissociation energies of F-2 and F-2(+) are determined as D-0(F-2)=1.606 +/- 0.001 eV and D-0(F-2(+))=3.334 +/- 0.001 eV, respectively. (C) 2005 American Institute of Physics.