Proton nuclear magnetic resonance spectroscopy solvents, effect

Charge transfer complexes of styrene and acrylonitrile have been shown to exist when in the presence of zinc chloride. Proton nuclear magnetic resonance spectroscopy has been used to establish this effect. In the proper solvents styrene and acrylonitrile will form occluded macroradicals which may then be used to form block copolymers. These block copolymers occur both in the presence and absence of zinc chloride. Pyrolysis gas chromatography, differential scanning calorimetry, and solubility studies show the properties of the two copolymers and their various block copolymers to be quite similar. Differences in the copolymers may be seen from carbon-13 nuclear magnetic resonance spectroscopy. Yield data for the block copolymers is reported. 

For its H-NMR (Nuclear Magnetic Resonance Spectroscopy), the two P-protons (HP) show up at 6.32 ppm, whereas the two a-protons (Ha) show up at 6.87 ppm, further down field from the two p-protons, because of the inductive effect from the nitrogen atom. As far as die NH is concerned, its chemical shift often is affected by solvents and concentrations for the NMR samples. The coupling constant between Ha and HP is 2.6 Hz, whereas the coupling constant between HP and HP is 3.4 Hz. 

Ronayne, J., Williams, D. H. Solvent Effects in Proton Magnetic Resonance Spectroscopy. Annual Review of NMR Spectroscopy, Vol. 2,pp. 83-124, New York 1969. Laszlo, P. Solvent Effects and Nuclear Magnetic Resonance. Progr. N.M.R. Spectroscopy 3, 231-403(1968). 

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