Structural study of salt forms of amides; paracetamol, benzamide and piperine

- Single crystal structures of 6 salt forms of pharmaceutical amides.
- Salt structures of paracetamol and benzamide with organic anions.
- Systematic changes to molecular geometry on protonation.
- Hemi-halide forms feature robust amide to amide OH⋯O interaction.
- Orthorhombic paracetamol isolated from aqueous Ba solutions.