Infrared C–D Stretching and<sup>2</sup>H NMR Spectra of Isopropyl-2-<i>d</i>1-(<i>p</i>-Substituted Phenyl)ethyl Ketones. Evidence for the Hydrogen Bond-Like Interaction between C–D Group and Aromatic π-Electrons
Isopropyl-2-d 1-(p-X-phenyl)ethyl ketones (where, X=H, NO2, Br, Cl, C2H5, CH3, and NH2) were shown to have two absorption bands in the C–D stretching region. The absorption band at the higher frequency (ca. 2177 cm−1) is assigned to the C–D···π approached conformer, and the high frequency shift is ascribed to the effect of steric compression. Weak C–D···π hydrogen bond was shown to occur by the measurement