Complementarity principle in heteromeric assembling via NH⋯O, CH⋯O, CH⋯π, and π⋯π interactions in the crystal structure of [(1R)-2-(benzyloxy)-2-oxo-1-phenylethyl]ammonium 4-methyl-1-benzenesulphonate

The complementarity principle, a basic concept of the crystal packing, is illustrated by the presented crystal structure optimising numerous noncovalent interactions: hydrogen bonding, CH⋯π, π⋯π interactions, and pronounced electrostatic interactions. Hydrogen bonds acting between polar parts of cations and anions organise molecules in one-dimensional pattern with a hydrophilic interior, while the complementary shaped hydrophobic parts use CH⋯π and π⋯π interactions to complete the crystal structure. The criteria for the close packing of ions are confronted requirements of hydrogen bonding directionality between the counter ions and chirality of cation. These conflicting demands are satisfied by the doubling of the asymmetric unit.