Bis(2-amino-5-benzyl-3-eth­oxy­carbonyl-4,5,6,7-tetra­hydro­thieno[3,2-c]pyridin-5-ium) bis­(4-meth­oxy­phen­yl)di­phos­phon­ate

The asymmetric unit of the title salt, 2C(17)H(21)N(2)O(2)S(+)·C(14)H(14)O(7)P(2) (2−), contains half of a centrosymmetric bis­(4-meth­oxy­phen­yl)di­phospho­nate anion and one 2-amino-5-benzyl-3-eth­oxy­carbonyl-4,5,6,7-tetra­hydro­thieno[3,2-c]pyri­din-5-ium cation. In the anion, the O atoms of the di­phospho­nate group are disordered over two positions with equal occupancies. In the cation, the ethyl group is disordered over two orientations with a refined occupancy ratio of 0.753 (5):0.247 (5), and the tetra­hydro­pyridinium ring adopts a distorted half-chair conformation. In the crystal, the ions are linked by C—H⋯O, N—H⋯O and C—H⋯S hydrogen bonds into a three-dimensional network.