The methanol sesquisolvate of sodium naproxen

Abstract

The asymmetric unit of the methanol solvate of sodium naproxen, systematic name: sodium (2S)-2-(6-methoxynaphthalen-2-yl)propanoate methanol sesquisolvate, Na+·C14H13O3 −·1.5CH3OH, comprises two formula units of the molecular salt and three methanol molecules. One of the sodium cations exhibits a coordination number of six and is bonded to three carboxylate O atoms and three methanol OH groups whereas the second sodium cation has a coordination number of seven, defined by five carboxylate O atoms and two methanol OH groups. Both coordination polyhedra around the sodium cations are considerably distorted. The two types of cations are bridged into polymeric chains extending parallel to [010]. This arrangement is stabilized by intrachain O—H...O hydrogen bonds between methanol ligands as donor and carboxylate O atoms as acceptor groups. The hydrophobic 6-methoxynaphthyl moieties flank the hydrophilic sodium oxygen chains into ribbons parallel to [010]. There are no noticeable intermolecular interactions between these ribbons. One of the 6-methoxynaphthyl moieties is disordered over two sets of sites in a 0.723 (3):0.277 (3) ratio.