TY - JOUR
T1 - N2O
T2 - A case study for acceleration region kinetics in a double-focusing mass spectrometer with a conventional nier-type ion source
AU - Koyanagi, G.K.
AU - McMahon, A.W.
AU - March, R.E.
AU - Harrison, A.G.
PY - 1989/2/15
Y1 - 1989/2/15
N2 - A method is presented for the investigation of unimolecular reactions of short-lived ionic species and ion/molecule reactions occurring in the acceleration region of a double-focusing mass spectrometer equipped with a standard Nier-type ion source. This method, which is described as acceleration region kinetics (ARK), has been applied initially to an investigation of ionic species formed from nitrous oxide. N2O, 15NNO, N15NO, N218O and 15NH4NO3 have been employed in this study. The temporal range of dissociative lifetimes accessible within the acceleration region is estimated as 10-9-10-7 s. The determination of half-lives of N2O+·* in non-competing reactions to yield NO+ and N+·2 has been carried out using ARK and has been compared with the results of linked-scans at constant B2/E, where B and E represent magnetic and electric fields, respectively. Releases of kinetic energy have been measured in the second field-free region of the mass spectrometer for reactions of N2O+·, N2O2+ and isotopically substituted analogues. The kinetic energy release associated with extrusion of the central N atom in isotopically labelled N2O+· is virtually indistinguishable from that accompanying loss of the terminal N atom. Collision induced dissociation has been employed to demonstrate the contribution of N2O+· in excited states to the dissociative channel leading to N+·2 and O, a reaction having a greater energy requirement than that leading to NO+ and N·. The release of kinetic energy associated with charge separation of the dication, N2O2+, to form NO+ and N+ was observed to be greater than published values, and the existence of the competing channel to form N+·2 and O+· is disputed. Isotopic labelling has been used to support the claim that ion signals ascribed previously to N+·2 and O+· are due to CO+· and O+· from charge separation of CO2+2 dications isobaric with N2O2+ dications
AB - A method is presented for the investigation of unimolecular reactions of short-lived ionic species and ion/molecule reactions occurring in the acceleration region of a double-focusing mass spectrometer equipped with a standard Nier-type ion source. This method, which is described as acceleration region kinetics (ARK), has been applied initially to an investigation of ionic species formed from nitrous oxide. N2O, 15NNO, N15NO, N218O and 15NH4NO3 have been employed in this study. The temporal range of dissociative lifetimes accessible within the acceleration region is estimated as 10-9-10-7 s. The determination of half-lives of N2O+·* in non-competing reactions to yield NO+ and N+·2 has been carried out using ARK and has been compared with the results of linked-scans at constant B2/E, where B and E represent magnetic and electric fields, respectively. Releases of kinetic energy have been measured in the second field-free region of the mass spectrometer for reactions of N2O+·, N2O2+ and isotopically substituted analogues. The kinetic energy release associated with extrusion of the central N atom in isotopically labelled N2O+· is virtually indistinguishable from that accompanying loss of the terminal N atom. Collision induced dissociation has been employed to demonstrate the contribution of N2O+· in excited states to the dissociative channel leading to N+·2 and O, a reaction having a greater energy requirement than that leading to NO+ and N·. The release of kinetic energy associated with charge separation of the dication, N2O2+, to form NO+ and N+ was observed to be greater than published values, and the existence of the competing channel to form N+·2 and O+· is disputed. Isotopic labelling has been used to support the claim that ion signals ascribed previously to N+·2 and O+· are due to CO+· and O+· from charge separation of CO2+2 dications isobaric with N2O2+ dications
UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-0006424497&partnerID=MN8TOARS
U2 - 10.1016/0168-1176(89)80027-8
DO - 10.1016/0168-1176(89)80027-8
M3 - Article
SN - 0168-1176
VL - 87
SP - 249
EP - 274
JO - International Journal of Mass Spectrometry and Ion Processes
JF - International Journal of Mass Spectrometry and Ion Processes
IS - 3
ER -
