Knowledge Bank

The ultraviolet spectrum of cyclobutanone vapour has been recorded under conditions of high resolution. The oxygen wagging vibrational levels have been found to be strongly anharmonic in the $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}A2$ electronic state and have been fitted to a double minimum potential function with a central barrier of $1550cm-1$. A double minimum potential function was used to describe ring puckering. A barrier greater than $100cm-1$ gave the best fit to the intensity of the (2-0) transition.