Knowledge Bank

“Infrared spectra (solution and vapor) have been obtained for p-benzoquinone, p-benzoquinone-$d1,-2,5-d2,-2,6-d2$, and $-d4$. In addition, solution spectra were it obtained for quinone-$O213$ and quinone-$d4,-O218$. These data, together with normal coordinate $calculations1$, and new Raman spectra of quinone, quinone-$2,5-d2$ and quinine-$d4\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$ were used to establish virtually complete vibrational assignments for this series of molecules. Changed in the infrared spectrum of quinone in the carbonyl stretching region with isotopic substitution and with change of solvent demonstrate conclusively the presence of Fermi resonance involving the $C=O$ fundamental in quinone, quinone-$2,5-d2$ and quinone-$d4$, but not in the other molecules.”