[{"from": "human", "value": "Design a molecule that meets the criteria outlined in the description. The molecule is an organic cation that is the conjugate acid of dimethylamine; major species at pH 7.3. It is an organic cation and a secondary aliphatic ammonium ion. It is a conjugate acid of a dimethylamine."}, {"from": "gpt", "value": "[C][NH2+1][C]"}]