C/C(=N\Nc1ccccc1Br)c1cccc(/C(C)=N/Nc2ccccc2Br)n1
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?