[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an organophosphonate oxoanion that is the conjugate base of phosphonoacetaldehyde, arising from deprotonation of one of the two phosphonate OH groups; major species at pH 7.3. It is a conjugate base of a phosphonoacetaldehyde."}, {"from": "gpt", "value": "[C][Branch1][Ring1][C][=O][P][=Branch1][C][=O][Branch1][C][O][O-1]"}]