O=C(Cc1ccc(-n2c(=S)[nH]c3ccccc3c2=O)cc1)N1CCN(c2ccccc2)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?