COc1cccc(C(C#N)NNC(=O)c2c(Cl)c(Cl)c(Cl)c(Cl)c2-c2nc3cc(C(=O)c4ccccc4)ccc3[nH]2)c1O
The electronegative atoms usually involved in hydrogen bonding are oxygen, nitrogen and fluorine. How many hydrogen bond acceptors does the molecule contain?