Clc1ccc(C[n+]2c(-c3ccccc3)cc(-c3ccccc3)cc2-c2ccccc2)cc1.[O-][Cl+3]([O-])([O-])[O-]
A rotatable bond is defined as any single non-ring bond, attached to a non-terminal, non-hydrogen atom. Amide C-N bonds are not counted because of their high barrier to rotation.  How many rotatable bonds does the molecule have?