Self-assembly of molecular ions via like-charge ion interactions and through-space defined organic domains.

Reaction stoichiometry, dynamic light scattering, and DFT are used to explore tertiary ammonium bicarbonates that exist as ideal solutes and those that self-assemble. Self-assembling tertiary amines featured organic surfaces beyond a through-space defined sphere around the charge center. Like-charge hydrogen-bonded ion pairs (or anti-electrostatic hydrogen bonding (AEHB)) also play a role in the self-assembly and provide the first evidence of this bonding motif by bicarbonate in aqueous solution. A single crystal neutron structure of a tertiary ammonium bicarbonate featuring a bicarbonate dimer is presented.