The molecule is the dianion obtained by deprotonation of the phenol and carboxy functions of (4-hydroxy-3-nitrophenyl)acetic acid. It is a monocarboxylic acid anion and a phenolate anion. It is a conjugate base of a (4-hydroxy-3-nitrophenyl)acetate.
2-(3-nitro-4-oxidophenyl)acetate