Comparison of the zero-field pulsing technique and the ICR [ion cyclotron resonance] technique for studying ion-molecule reactions

1970 ◽  
Vol 74 (13) ◽  
pp. 2720-2722 ◽  
Author(s):  
A. A. Herod ◽  
Alexander George Harrison ◽  
Rebecca M. O'Malley ◽  
A. J. Ferrer-Correia ◽  
K. R. Jennings
Keyword(s):  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Zero Field ◽  
Resonance Technique ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron

Time-resolved ion cyclotron resonance

1978 ◽  
Vol 364 (1718) ◽  
pp. 367-381 ◽  
Keyword(s):  
Cyclotron Resonance ◽  
Low Energy ◽  
Interstellar Space ◽  
Ion Cyclotron Resonance ◽  
Absolute Rate ◽  
Time Resolved ◽  
Ion Molecule Reactions ◽  
Quadrupole Trap ◽  
Ion Cyclotron ◽  
Improved Technique

Ion cyclotron resonance (i. c. r.) is a technique for the study of ion-molecule reactions in the collisional range from thermal to several electron volts. The study of these reactions at low energy has been given impetus by the discovery of their importance in the ionosphere and in interstellar space. This communication identifies some possible weaknesses inherent in current i. c. r. work and suggests an improved technique with which it is possible to determine absolute rate constants more reliably. As an illustration of the technique a measurement of the rate constant for the reaction CH 4 + + CH 4 → k CH 5 + + CH 3 is presented. This value is k = 1.21 ± 0.09 × 10 -15 m 3 s -1 . A new i. c. r. cell design is discussed with which it is hoped to provide further improvement in reliability by the production of a homogeneous radiofrequency field within a true quadrupole trap.

Mechanism and Structure in the Ion Chemistry of Tetramethyldiphosphine: An Ion Cyclotron Resonance Spectrometric Study

1976 ◽  
Vol 31 (5) ◽  
pp. 414-421 ◽  
Author(s):  
Karl-Peter Wanczek
Keyword(s):  
Mass Spectrum ◽  
Rate Constants ◽  
Cyclotron Resonance ◽  
Double Resonance ◽  
Ion Cyclotron Resonance ◽  
Spectrometric Study ◽  
Ion Chemistry ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Ion Cyclotron Resonance Spectrometry

Abstract The mass spectrum of tetramethyldiphosphine and the ion chemistries of this compound and of its mixtures with phosphine and dimethylphosphine have been investigated by ion cyclotron resonance spectrometry. Numerous ion molecule reactions have been observed. The rate constants of the two most abundant ions formed by the molecular ion, the tetramethyldiphosphonium ion, H(CH3)2P-P(CH3)2+ and the hexamethyltriphosphonium ion, P3(CH3)6+ , are k2.35≦0.1X10-10 cm3 molecule-1 s-1 and k2.40 = 1.5 X10-10 cm3 molecule -1 s -1 respectively. The structures of several ions have been determined with the aid of their ion-molecule reactions. The ions m/e = 79 and 93 are thought to have the structures HP - P(CH3)H+ and HP-P(CH3)2+ . The most probable structures of the ions m/e = 169 and 183 are HP(CH3)2-P(CH3)-P(CH3)2+ and (CH3)2P-P(CH3) - P(CH3)3+ . The protonated molecule undergoes several ion-molecule reactions, which proceed via an intermediate, m/e = 183, [(CH3)6P3+]* which is detected by double resonance experiments.

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