Selective detection of the tolyl cation among other [C7H 7] (+) isomers by ion/molecule reaction with dimethyl ether
T G Heath1, J Allison, J T Watson
1Department of Biochemistry, Biochemistry Building, Michigan State University, 48824, East Lansing, MI.
Abstract:
The ion/molecule reaction of the tolyl cation with dimethyl ether has been investigated using triple quadrupole mass spectrometry. Three isomers with [C7H7](+) composition, the 3-tolyl, benzyl, and tropylium cations, were individually selected and reacted with dimethyl ether at a pressure of 1 mtorr in the second quadrupole (Q2) collision cell. Only the tolyl ion reacted to yield a methoxylated product ion peak at m/z 122. This reaction product having m/z 122 is postulated to be identical in structure with the molecular ion of 3-methyl anisole, as supported by thermochemical data and the similarity of the collision induced dissociation (CID) daughter ion mass spectra of the product ion and the molecular ion of authentic 3-methyl anisole. The daughter ion mass spectra of the three [C7H7](+) isomers during CID, by using a triple quadrupole mass spectrometer, are nearly identical; on the other hand, the analytical approach based on the ion/molecule reaction with dimethyl ether clearly exhibits distinct gas-phase chemistry reflecting structural differences among the isomers. Sot.
More Related Videos
07:50Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
Related Concept Videos
01:21Chemical Ionization (CI) Mass Spectrometry
01:17Thermal Electrocyclic Reactions: Stereochemistry
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
02:36Crown Ethers
01:20¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
02:34Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
02:17Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...