Crystal structure of a host–guest complex of the tris-urea receptor, 3-(4-nitrophenyl)-1,1-bis{2-[3-(4-nitrophenyl)ureido]ethyl}urea, that encapsulates hydrogen-bonded chains of dihydrogen phosphate anions with separate tetra-<i>n</i>-butylammonium counter-ions
Acta crystallographica. Section E, Crystallographic communications