Dianilinium bis(pyridine-2,6-dicarboxylato-κ3O2,N,O6)cuprate(II) hexahydrate

The asymmetric unit of the title complex, (C6H8N)2[Cu(C7H3NO4)2]·6H2O, contains half a copper(II)–dipicolinate complex located on a twofold rotation axis, one protonated aniline molecule and three solvent water molecules. The CuIIatom is coordinated by four O atoms and two N atoms from two dipicolinate ligands in a distorted octahedral environment. In the crystal, the components are linked into a three-dimensional framework by intermolecular O—H...O and N—H...O interactions.

Substituent Effects on the Acidity of Weak Acids. 4. Anilinium Ions

The gas phase acidity of anilinium ions has been calculated at a number of theoretical levels from B3LYP/6-311++G** to MP2 and CCSD/6-311++G(2dp,2pd). The highest level calculations find anilinium ion and p-protonated aniline to have essentially the same energy, in agreement with experimental studies. They also give a proton affinity for aniline that is in very good agreement with the experimental value. The B3LYP and MP2 calculations are less successful, with B3LYP favoring p-protonation and MP2 favoring N-protonation for aniline. Despite this difficulty, the calculated effect of substituents on the proton affinities of p-substituted anilines that undergo N-protonation agreed well with the experimental data. The effect of substituents on the anilinium ions and on the anilines were examined separately using a series of group transfer reaction.