O=C1C(O)=C(Br)C(=O)C(O)=C1Br    mol9609    0_1
O=C1C(O)=C(Br)C(=O)C([O-])=C1Br    mol9609    -1_1
O=C1C([O-])=C(Br)C(=O)C([O-])=C1Br    mol9609    -2_1