Knowledge Bank

The microwave spectrum of 6-hydroxy-2-formyl-fulvene has been studied in order to determine the nature of its hydrogen bonding potential. Assignments made for the ground state have shown that the rotational states have statistical weights characteristic of a $C2$ axis. The observed A-type lines fit a rigid rotor spectrum with A=2816.41. B=1613.433, and C=1025.852 MHz. The inertial defect for this planar molecule is --0.030 Amu \AA$\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$. The statistical weights and the observed lack of deviation from a rigid rotor spectrum suggests that the hydrogen bond-stretching potential has a symmetric single minimum or very low double minimum. Work is continuing on vibrational states and isotopic derivatives.