O=C1CN2CCN(CC2)CC(=O)Nc2ccc(cc2)S(=O)(=O)c2ccc(cc2)NC(=O)CN2CCN(CC2)CC(=O)Nc2ccc(cc2)S(=O)(=O)c2ccc(cc2)N1
A higher negative pKa value denotes a less powerful acid. What is this molecule's negative pKa value?