With what neutral molecule is `CIO^-` isoelectronic? Is that molecule a Lewis base?

Explanation

`ClO^-` is iso-electronic with CIF (replace `O^-` with `F`-bond have 9 electrons each). Both `ClO^-` and CIF have 26 electrons each.
Yes, CIF is a Lewis base as Cl atom can accept a pair of electrons and expand its octect. It is due to the presence of vacant d-subshell in the valence shell of chlorine.