New catalytically active neodymium sulfate

Abstract

Two novel isotopic rare earth sulfates, R(SO₄)₂·NH₄ (R = Nd, Eu), have been synthesized hydrothermally at 170 °C for 5 days. The crystal structures of these compounds have been established by single crystal X-ray diffraction to be the monoclinic space group P2₁/c, with a = 8.867(1), b = 7.187(1), c = 10.804(2) Å, β = 91.653(3)° and Z = 4 for Nd(SO₄)₂·NH₄. The structure can be conceived as being formed of parallel layers [R(SO₄)₂]⁻, in which a honeycomb (6, 3) layer of sharing edge RO₉ polyhedra is bonded to different isolated SO₄ tetrahedra. Inside the inter-block space a row of NH₄⁺ ions are hosted, which connect the layers through hydrogen bonds. The magnetic measurements, and catalytic studies of the Nd(SO₄)₂·NH₄ in alkene hydrogenation, and selective oxidation of organic sulfides are reported. This material shows good activity and selectivity, and can be reused for at least four cycles without significant loss in catalytic activity.