Knowledge Bank

About fifty a- and b-type transitions have been measured and assigned for disilanyl fluoride $(Si2H5F)$. Many of the lines are split due to tunnelling through the barrier to internal rotation about the Si--Si bond. Analysis of these splittings gives a barrier value of 1,048 cal/mole. The ground-state rotational constants of the A and E levels are: $AA=16,025.78McAE=16,023.66McBA=3,338.26McBE=3,338.25McCA=2,948.60McCE=2,948.60Mc$ Structural calculations give a preliminary value for the Si-Si bond distance of $2.33\backslash AA$. This corresponds to a single-bond value and is consistent with the low barrier. A preliminary value of the dipole moment is $\mu =1.23D$. $\mathrm{<mrow\; data-mjx-texclass="ORD">\ast </mrow>}$This research was made possible by support extended Harvard University by the Office of Naval Research.