CC1(C)Cc2c(cnn2-c2ccccc2)-c2c1c1ccccc1n2CC(O)CCl
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?