A co-crystal of nona-hydrated disodium(II) with mixed anions from m-chloro-benzoic acid and furosemide.

In the title compound, [Na2(H2O)9](C7H4ClO2)(C12H10ClN2O5S) {systematic name: catena-poly[[[triaquasodium(I)]-di-μ-aqua-[triaquasodium(I)]-μ-aqua] 3-chlorobenzoate 4-chloro-2-[(furan-2-ylmethyl)amino]-5-sulfamoylbenzoate]}, both the original m-chloro-benzoic acid and furosemide exist with deprotonated carboxyl-ates, and the sodium cations and water mol-ecules exist in chains with stoichiometry [Na2(OH2)9](2+) that propagate in the [-110] direction. Each of the two independent Na(+) ions is coordinated by three monodentate water mol-ecules, two double-water bridges, and one single-water bridge. There is considerable cross-linking between the [Na2(OH2)9](2+) chains and to furosemide sulfonamide and carboxyl-ate by inter-molecular O-H⋯O hydrogen bonds. All hydrogen-bond donors participate in a complex two-dimensional array parallel to the ab plane. The furosemide NH group donates an intra-molecular hydrogen bond to the carboxyl-ate group, and the furosemide NH2 group donates an intra-molecular hydrogen bond to the Cl atom and an inter-molecular one to the m-chloro-benzoate O atom. The plethora of hydrogen-bond donors on the cation/water chain leads to many large rings, up to graph set R 4 (4)(24), involving two chains and two furosemide anions. The chloro-benzoate is involved in only one R 2 (2)(8) ring, with two water mol-ecules cis-coordinated to Na. The furan O atom is not hydrogen bonded.