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Characterization of tetra-aryl benzene isomers by using preparative gas chromatography with mass spectrometry, nuclear magnetic resonance spectroscopy, and x-ray crystallographic methods
journal contribution
posted on 2023-05-17, 03:02 authored by Ruehle, CPG, Niere, J, Morrison, PD, Jones, RC, Caradoc-Davies, T, Allan CantyAllan Canty, Michael GardinerMichael Gardiner, Tolhurst, V, Marriott, PJThe present study describes a preparative gas chromatographic (GC) approach employed to study a series of products arising from reaction of phenylacetylene with para-substituted aryl-iodides under Sonogashira catalysis conditions. GC analysis resolves the isomers from each reaction; however, it cannot provide structural details (their MS data are virtually identical). Since classical liquid chromatography cannot resolve the isomers, preparative-scale GC is the only practical approach to provide further spectroscopic characterization of the isomers. The products are well separated by GC so a single thick-film capillary column is adequate for this case, with operation up to +300 °C. By collection of 50+ repeat injections, sufficient material could be isolated for 1H NMR spectral analysis of the isomers, and for one isomer (isomer I) of a number of analogous related catalytic reaction mixtures, X-ray crystal structure determination enabled complete structural elucidation (absolute configuration) of the substitution pattern of the structure of this isomer. This confirmed isomer I to be the 2-para-aryl-substituted 1,3,5-triphenylbenzene product in all cases. 1H NMR spectra of isomer I products generally had similar patterns but differed markedly from the second major isomer product (isomer II).
History
Publication title
Analytical ChemistryVolume
82Issue
11Pagination
4501-4509ISSN
0003-2700Department/School
School of Natural SciencesPublisher
Amer Chemical SocPlace of publication
1155 16Th St, Nw, Washington, USA, Dc, 20036Rights statement
Copyright © 2010 American Chemical SocietyRepository Status
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