[{"from": "human", "value": "Please give me some details about this molecule. [C][C][N][Branch1][=Branch2][C][C][N][Ring1][=Branch1][C][C][O][C][C][S][=Branch1][C][=O][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is a HEPES that is ethanesulfonic acid in which one of the methyl hydrogens is replaced by a 4-(2-hydroxyethyl)piperazin-1-yl group. A Good's buffer substance, pKa = 7.55 at 20 \u2103. It is a HEPES and an organosulfonic acid. It is a conjugate acid of a 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonate. It is a tautomer of a 2-[4-(2-hydroxyethyl)piperazin-4-ium-1-yl]ethanesulfonate."}]