COc1cc2c(cc1Cl)[n+]([O-])c(C#N)c(N1CCN(c3ccc([N+](=O)[O-])cc3)CC1)[n+]2[O-]
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?