title: Photodissociation mass spectra and mass-selected resonant (1+1)-photodissociation spectroscopy of some alkyl iodide radical cations.
abstract: Photodissociation (PD) mass spectra and mass selected (1+1)-photodissociation spectra of C(2)H(5)I(+•), C(2)D(5)I(+•),1- C(3)H(7)I(+•), 2-C(3)H(7)I(+•), 1-C(4)H(9)I(+•) and 2- C(4)H(9)I(+•) radical cations were studied within the Ã ← X~ absorption band. The photodissociation mass spectra within the range 13,600-15,900 cm(-1) (1.68-1.97 eV) evidence only a simple cleavage of the C-I bond and formation of the corresponding alkyl ions. The resonant (1+1)-photodissociation spectra of C(2)H(5)I(+•) and C(2)D(5)I(+•) show intense vibrational structure in the excited Ã state. The thresholds for formation of the states of C(2)H(5)I(+•) and C(2)D(5)I(+•) were estimated to be (13,278 ± 12) cm(-1) (1.6462 ± 0.0014 eV)and (13,363 ± 12) cm(-1) (1.6586 ± 0.0014 eV), respectively. Whereas a few resonant vibronic excitations could be identified with 1-C(3)H(7)I(+•) and 1- C(4)H(7)I(+), no vibrational features were observable with 2- C(3)H(7)I(+•) and 2-C(4)H(9)I(+•). It is concluded that 1- and 2-iodoalkane radical cations do not rearrange, even under the conditions of electron ionisation used to generate the molecular ions.
authors.affiliation: Institut für Physikalische Chemie, Christian Albrechts Universität zu Kiel, Ludewig-Meyn-Straße 8, 24118 Kiel, Germany.
authors.forename: Hannes
authors.initials: H
authors.lastname: Schüttig
authors.forename: Jürgen
authors.initials: J
authors.lastname: Grotemeyer