Amine Superbases Stabilized by Extended Hydrogen Bond Networks

Extended hydrogen-bonding networks as a mechanism for creating superbases is explored through six different amine scaffolds: linear acenes, cyclohexane, decalin, triptycene, adamantane, and [2.2]­paracyclophane. The gas-phase proton affinities of 21 different potential superbases were computed at the ωB97X-D/6-311+G­(2d,p) level. This method was benchmarked against the experimental proton affinities of 44 nitrogen bases. Extended hydrogen-bonding networks, including second- and third-layer hydrogen bonding, led to bases with proton affinities 20 kcal mol^–1 greater than that of bis­(dimethylamino)­naphthalene. The strongest bases are the decalin base <b>25</b> and the adamantane base <b>31