Ethene-trans-1,2-bis(4-pyridinium) dihydrogenphosphite and dihydrogenphosphate compounds exhibiting cooperative and directed hydrogen bonds between cations and anions: H₂bpe(H₂PO₃) ₂ and H₂bpe(H₂PO₄) ₂·H₂O

H₂bpe(H₂PO₃)₂ (1) and H ₂bpe(H₂PO₄)₂·H₂O (2) (H₂bpe = ethene-trans-1,2-bis(4-pyridinium), H₂PO ₃ = dihydrogenphosphite, and H₂PO₄ = dihydrogenphosphate) have been prepared and structurally characterized. In compound 1, the dihydrogenphosphite anions form dimers, with a P⋯P distance of 4.2073(7) Å, by two O-H⋯H hydrogen bonds, and the dimeric dihydrogenphosphite units interact with the H₂bpe cations by way of N-H⋯O and O-H⋯O hydrogen bonds, resulting in a one-dimensional chain. The chains are held together by C-H⋯O interactions. In compound 2, the phosphate ions are connected by O-H⋯O hydrogen bonds into an unusual 2D square grid-type framework with P⋯P separations ranging from 4.7533(7) to 4.9506(8) Å. The H₂bpe cations crosslink the dihydrogen phosphate layers by N-H⋯O hydrogen bonds, forming a three-dimensional supramolecular network with channels. The water molecules in compound 2 occupy these channels and make O-H⋯O bonds to adjacent phosphate O atoms and also O-H⋯O bonds to the next water O atom in the channel.