Characterization of Tetra-aryl Benzene Isomers by Using Preparative Gas Chromatography with Mass Spectrometry, Nuclear Magnetic Resonance Spectroscopy, and X-ray Crystallographic Methods

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• 作者：Christian P. G. Rhle ; Julie Niere ; Paul D. Morrison ; Roderick C. Jones ; Tom Caradoc-Davies ; Allan J. Canty ; Michael G. Gardiner ; Vicki-Anne Tolhurst ; Philip J. Marriott
• 刊名：Analytical Chemistry
• 出版年：2010
• 出版时间：June 1, 2010
• 年：2010
• 卷：82
• 期：11
• 页码：4501-4509
• 全文大小：243K
• 年卷期：v.82,no.11(June 1, 2010)
• ISSN：1520-6882

文摘

The 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).