Three novel uranyl selenate and sulfate oxysalts templated by protonated azetidine molecules, [AzH]⁺, and its ring-opened counterpart 1-azetidinepropanamine, [AzH(CH₂)₃NH₃]²⁺, have been prepared and studied by X-ray structural analysis. Conformations of azetidinium cations were analysed by means of infrared vibrational assignments supported by the DFT calculations. Crystallization of [AzH]₂ [(UO₂)₂(SeO₄)₃(H₂O)] (I) from highly acidic solutions suggests that low pH does not necessarily result in the opening of azetidine ring. [AzH(CH₂)₃NH₃][(UO₂)₂(SeO₄)₃(H₂O)](H₂O) (II) and [AzH(CH₂)₃NH₃](H₅O₂)[(UO₂)₂(SO₄)₃(HSO₄)] (III) are the first structurally characterized crystalline compounds bearing isolated ring-opened azetidine moiety.