O=C1[C@H]2C(c3ccccc3[N+](=O)[O-])=[N+](c3ccccc3)O[C@H]2C(=O)N1c1ccc(Cc2ccc(N3C(=O)[C@H]4O[N+](c5ccccc5)=C(c5ccccc5[N+](=O)[O-])[C@H]4C3=O)cc2)cc1
Hydrogen bond acceptor is the chemical compound which contains the lone electron pairs that participate in the hydrogen bond formation. This compound should contain a more electronegative atom (more electronegative than hydrogen) with lone electron pairs. Then it can attract protons from a donor. Moreover, the electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?