Cc1ccc(N=C(S)N2CCCC(c3nc4cc(C)ccc4[nH]3)C2)c(C)c1
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?