Knowledge Bank

Deuteron quadrupole coupling strengths were measured in a number of small molecules using a molecular beam maser spectrometer. The resolution in the maser spectrometer is typically 6 kHz and hyperfine structure due to deuteron quadrupole coupling and spin-rotation interactions is well resolved. These splittings are too small to resolve in many cases using conventional techniques. Since the quadrupole moment of the deuteron is known this allows us to measure electric field gradients at positions of hydrogen nuclei in a molecule. This information is complementary to other parameters such as dipole moment and molecule quadrupole moment and significantly improves our experimental knowledge of electronic charge distributions. These experimental parameters may be combined to provide a good test for electronic structure calculations. We have recently observed hyperfine structure for DFCO, $CF3$, D and $CH2DCl$. Deuteron quadrupole coupling strenths and other interaction strengths will be reported and discussed.