A new pseudopolymorph of berberine chloride: crystal structure and Hirshfeld surface analysis

Abstract

A new pseudopolymorph of berberine, 9,10-dimethoxy-5,6-dihydro-2H-7λ5-[1,3]dioxolo[4,5-g]isoquinolino[3,2-a]isoquinolin-7-ylium chloride methanol monosolvate, C20H18NO4+·Cl−·CH3OH, was obtained during co-crystallization of berberine chloride with malonic acid from methanol. The berberine cations form dimers, which are further packed in stacks. The title structure was compared with other reported solvates of berberine chloride: its dihydrate, tetrahydrate, and ethanol solvate hemihydrate. Hirshfeld analysis was performed to show the intermolecular interactions in the crystal structure of the title compound, and its fingerprint plots were compared with those of the already studied solvates.

Keywords

• crystal structure
• stacking interactions
• methanol solvate
• hirshfeld surface analysis