Toward engineering of very strong organic bases: pronounced proton affinity of molecules possessing imino structural and electronic motif

The absolute proton affinity of a group of compounds involving AN imino group is examined by employing the MP2(fc)/6-311+G∗∗// HF/6-31G∗ + ZPVE(HF/6-31G∗) theoretical model. It appears that these systems exhibit high proton affinity thus representing good candidates for efficient proton sponges. Their heavily substituted derivatives, involving bulky alkyl groups, which protect the reactive double bonds, should possess even higher proton affinity being at the same time apt to chemical synthesis.