Knowledge Bank

Microwave and radiofrequency Stark spectra have been observed for $(NO)2$ is a pure singlet state, precise values have been determined for rotational, nuclear quadrupole coupling, and spin-rotation constants. The values obtained are as follows: \begin{eqnarray*} &A= 25829.4803(20) MHz, B = 5614.3093(4) MHz, C = 4605.4396 (12) MHz&\ &\chi_{aa} = -4.0652(2) MHz, \chi_{bb}-\chi_{cc} = -8.5498(6) MHz&\ &C_{aa} = 10.4(5) KHz, C_{bb} = 13.8(4) KHz, C_{cc} = 0.8 (4) KHz&\end{eqnarray*} The electric dipole moment of the dimer has also been determined, $\mu =0.17120(2)$ D. These data will be discussed in terms of the structure and bonding of the dimmer.