CCCCOc1ccc(C(=O)N/C(=C\c2ccc(OC)cc2)C(=O)OCc2ccco2)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?