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.

Mass Spectra and Ion Chemistry of Methylphosphine, Dimethylphosphine and Dimethyldeuterophosphine, Investigated by Ion Cyclotron Resonance Spectrometry

1975 ◽  
Vol 30 (3) ◽  
pp. 329-339 ◽  
Author(s):  
Karl-Peter Wanczek
Keyword(s):  
Rate Constants ◽  
Cyclotron Resonance ◽  
Mass Spectra ◽  
Ion Cyclotron Resonance ◽  
Exchange Reactions ◽  
Ion Chemistry ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron ◽  
Product Ions ◽  
Ion Cyclotron Resonance Spectrometry

The mass spectra and the ion molecule reactions of methylphosphine, dimethylphosphine and dimethyldeuterophosphine have been studied by ion cyclotron resonance spectrometry. About 50 ion molecule reaction are observed for each compound. The product ions can be classified as ions with two phosphorus atoms: P2R5+, P2R3+, P2R2+ and P2R+ (R = CH3 or H), as phosphonium and phosphinium ions and ions resulting from collision dissociations and charge exchange reactions. Tertiary ions with three phosphorus atoms like CH3P3H2+ (from CH3PH2) and (CH3)4P3H2 (from (CH3)2PH) have also been detected. The mechanisms of the ion molecule reactions, rearrangements, P -H- and C-H-reactivities and product ion structures are discussed, using in the case of dimethylphosphine the results obtained with the deuterated compound. Rate constants of formation of the more abundant product ions from the molecular ion and the CH3P+ ion, both odd electron particles, have been determined. The reactions with dimethylphosphine have much smaller rate constants than the reactions with methylphosphine.

Untersuchung der Ion-Molekül-Reaktionen des Thiothionylfluorids mit Hilfe der Ionen-Cyclotronresonanz-Spektrometrie / Investigation Of Ion-Molecule Reactions Of Thiothionylfluorid By Ion Cyclotron Resonance Spectrometry

1972 ◽  
Vol 27 (1) ◽  
pp. 155-158 ◽  
Author(s):  
K.-P. Wanczek ◽  
K.-H. Lebert ◽  
H. Hartmann
Keyword(s):  
Mass Spectrum ◽  
Chemical Reactions ◽  
Rate Constant ◽  
Cyclotron Resonance ◽  
Ion Cyclotron Resonance ◽  
Consecutive Reaction ◽  
Ion Molecule Reactions ◽  
Secondary Ions ◽  
Ion Cyclotron ◽  
Ion Cyclotron Resonance Spectrometry

Abstract The ion-molecule reactions of thiothionylfluoride have been studied by ion cyclotron resonance spectrometry. The major secondary ions are S2F3+ , S3F+ , and S3F2+. In a consecutive reaction of S3F2+ the tertiary ion S4F2+ is formed. The rate constant of the IMR with the greatest yieldS2F2+ + SSF2 → S3F2+ + SFwas estimated tok = 2 · 10-9 cm 3 molecule -1 sec -1 .The results were compared with the mass spectrum of thiothionylfluoride. They permit conclusions on chemical reactions of lower sulphurfluorides.

Proton transfer as a first step in ion-molecule reactions of diethyl ether and tetrahydrofuran

1976 ◽  
Vol 29 (8) ◽  
pp. 1837
Author(s):  
T McAllister
Keyword(s):  
Proton Transfer ◽  
Mass Spectrometer ◽  
Diethyl Ether ◽  
Cyclotron Resonance ◽  
Double Resonance ◽  
Ion Cyclotron Resonance ◽  
Ion Molecule Reactions ◽  
Ion Cyclotron

Mechanisms may be written for several of the ion-molecule reactions in tetrahydrofuran and diethyl ether for which the first step is protonation to give the ion (M+l)+. This hypothesis was tested inan ion cyclotron resonance mass spectrometer by double-resonance experiments on mixtures of each of the ethers with methane. It was shown that CH5+ is a precursor for the tetrahydrofuran reactions,but not, with one exception, for the diethyl ether reactions.

Bimolecular production of gas phase ionic hydrates by ion cyclotron resonance spectroscopy

1980 ◽  
Vol 58 (8) ◽  
pp. 863-865 ◽  
Author(s):  
R. L. Clair ◽  
T. B. McMahon
Keyword(s):  
Gas Phase ◽  
Cyclotron Resonance ◽  
Resonance Spectroscopy ◽  
Ion Cyclotron Resonance ◽  
Ion Chemistry ◽  
Ion Molecule Reactions ◽  
Hydronium Ion ◽  
Dominant Feature ◽  
Ion Cyclotron ◽  
Gas Phase Ion

The gas phase ion–molecule reactions of α,α,α′,α′ tetrafluorodimethyl ether both alone and in mixtures with water have been examined. The dominant feature of the ion chemistry of these mixtures is the sequential bimolecular production of the hydrated hydronium ion, H5O2+. Two independent mechanistic pathways for production of H5O2+ are outlined arising from reaction of H3O+ with (CF2H)2O and from CF2H—O=CHF+ with H2O. Implications for examination of solvent switching equilibria are discussed.

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