O=C1c2cccnc2C(=O)c2c1nc1ccccc1c2-c1ccc2c3c(nc4ccccc42)C(=O)c2cccnc2-c13
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?