CCCC(=O)OC[n+]1cccc(-c2c(COC(=O)NC(C)C)c(COC(=O)NC(C)C)c3n2CCC3)c1.[I-]
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?