O=Cc1ccc(OCc2cccc(COc3ccc(/C=N\Nc4ccc([N+](=O)[O-])cc4[N+](=O)[O-])cc3)n2)cc1
Hydrogen bond acceptor: The atom, ion, or molecule component of a hydrogen bond which does not supply the bridging (shared) hydrogen atom. How many hydrogen bond acceptors does the molecule have?