Synthesis and Crystal Structure of Sodium Arsenate Oxyhydroxide: Na\u3csub\u3e4\u3c/sub\u3e(AsO\u3csub\u3e4\u3c/sub\u3e)OH

Single crystals of Na4(AsO4)OH were grown using the hydroflux method and characterized by single crystal X-ray diffraction. Na4(AsO4)OH crystallizes in the orthorhombic space group Pnma with a = 8.9467(11) Å, b = 7.3854(9) Å, and c = 8.2395(10) Å. The moisture sensitive material exhibits a three-dimensional crystal structure consisting of isolated AsO4 3− tetrahedra with the charge balance maintained by Na+ and OH−. The asymmetric unit consists of one arsenic atom, three sodium atoms, four oxygen atoms, and one hydroxyl hydrogen atom. Arsenic, sodium, and oxygen atoms, as well as the hydroxyl hydrogen, are located on mirror planes; sodium is located on an inversion center