9-O-Ethylberberrubinium iodide monohydrate

In the title compound (systematic name: 9-ethoxy-10-methoxy-5,6-dihydro-1, 3-dioxolo[4,5-g]isoquinolino-[3,2-a]isoquin-olin-7-ium iodide monohydrate), 2C₂₁H₂₀NO₄⁺·2I ^-·H₂O, two independent molecules pack in the unit cell, where interactions between the molecules are stabilized by weak inter-molecular π-π stacking interactions [centroid-centroid distances in the range 3.571 (4) to 3.815 (4)Å]. Inter-molecular C - H⋯O interactions are also observed. The iodide anions are disordered with occupancy ratios of 0.94 (1):0.06 (1) and 0.91 (1):0.09 (1). The cationic molecule is planar in structure with a small torsion resulting from the dihydropyridine ring.