The reaction of sodium N-morpholine acetate with selenic and sulfuric acid and uranyl nitrate results in the formation of two novel open-framework compounds, |Na(Hmfa)|[(UO ₂) ₂(SeO ₄) ₃(H ₂O)](H ₂O) ₂ (NaUSe) and [Na ₂(SO ₃OH)(Hmfa)]|(UO ₂)(SO ₄) ₂| (NaUS), respectively. Despite identical synthetic procedures, sulfate structure dramatically differs from selenate compound. Their common feature is an open-framework featuring two-dimensional system of channels occupied by protonated morpholino-N-acetic acid species. Coordination of Na atoms is different. In NaUSe, [(UO ₂) ₂ (SeO ₄) ₃(H ₂O)] ^2- layers are pillared by {Na ₂O ₈(H ₂O) ₂(Hmfa) ₂} complexes to form a microporous framework. In NaUS, UO ₇ and SO ₄ polyhedra of [(UO ₂)(SO ₄) ₂] ^2- chains share common oxygen atoms with Na-centered tetrameric complexes providing a three-dimensional integrity of the structure. Both of the compounds are characterized by IR spectroscopy.