The Nuclear Spin and Quadrupole Moment ofI131

Measurements on the $J=2\mathrm{}\to 3$ rotational transition of C${\mathrm{H}}_3$ ${\mathrm{I}}^{131}$ have been made in the 6.75-mm wavelength region. The nuclear spin of ${\mathrm{I}}^{131}$ was found to be $\frac{7}{2}$ and the quadrupole coupling, -973±9 Mc/sec. This coupling gives -0.412×${10}^{-24\mathrm{}}$ ${\mathrm{cm}}^2$ for the quadrupole moment of ${\mathrm{I}}^{131}$.