CC(=O)[O-].Cc1cccc2nc3cccc(C(=O)NCCC[N+](C)(CCCNC(=O)c4cccc5nc6cccc(C)c6nc45)Cc4c([N+](=O)[O-])ncn4C)c3nc12
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?