Propane-1,3-diaminium bis-(tetra-fluoro-borate)-18-crown-6 (1/2).

In the title compound, C(3)H(12)N(2) (2+)·2BF(4) (-)·2C(12)H(24)O(6), the central C atom of the propane-1,3-diammonium cation lies on a crystallographic twofold rotation axis. The terminal NH(3) (+) groups insert into the crown rings through strong N-H⋯O hydrogen-bonding inter-actions, resulting in the formation of a 1:2 supra-molecular [(C(3)H(12)N(2))·(C(12)H(24)O(6))(2)](2+) complex. The anions are linked to the supra-molecular complexes via weak C-H⋯F hydrogen bonds. The F atoms of the anion are disordered over two orientations with site occupancies of 0.5.