COC(=O)c1ccc(COc2ccccc2/C=C(\C#N)C(=O)Nc2c(C)cccc2C)cc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?