[{"from": "human", "value": "Create a molecule with the structure as the one described. The molecule is a dicarboxylic acid monoanion that is the conjugate base of butynedioic acid. It is a conjugate base of a butynedioic acid. It is a conjugate acid of an acetylenedicarboxylate(2-)."}, {"from": "gpt", "value": "[C][#Branch1][#Branch1][#C][C][=Branch1][C][=O][O-1][C][=Branch1][C][=O][O]"}]