Host–guest‐like thi­amine–anion complexation in thia­minium bis­(tetra­fluoro­borate)

In the title compound, 3‐(4‐amino‐2‐methyl‐5‐pyrimidin‐1‐io)methyl]‐5‐(2‐hydroxy­ethyl)‐4‐methyl­thia­zolium(2+) bis(tetra­fluoro­borate), C₁₂H₁₈N₄OS²⁺·2BF₄^?, the divalent thia­mine cation (in the F conformation) is associated with BF₄^? anions via two characteristic bridging interactions between the thia­zolium and pyrimidinium rings, i.e. C—H?BF₄^??pyrimidinium and N—H?BF₄^??thia­zolium interactions. Thi­amine mol­ecules are linked by N—H?O hydrogen bonds to form a helical chain structure.