O=[N+]([O-])c1cc([N+](=O)[O-])c2c(Nc3ccccc3)n(-c3ccccc3)[n+]([O-])c2c1
The donor in a hydrogen bond is usually a strongly electronegative atom such as N, O, or F that is covalently bonded to a hydrogen bond. How many hydrogen bond donors does the molecule have?