Phase Transition Originating from Disorder–Order Transformation Coupled with Reorientation in the Organic–Inorganic Hybrid Compound (C₄H₁₄N₂)[Cd₂(H₂O)₆(SO₄)₃]

Abstract

The organic-inorganic hybrid compound 1,4-butyldiammonium hexaaquadicadmium(II) trisulfate (C 4 H 14 N 2 )[Cd 2 -(H 2 O) 6 (SO 4 ) 3 ] (1) was synthesized by the reaction of 3CdSO 4 ·8H 2 O with 1,4-butanediamine in sulfuric acid aqueous solution. Differential scanning calorimetry measurements indicate that 1 undergoes a reversible phase transition at 243.4 K with a thermal hysteresis of 3.3 K. Single-crystal X-ray diffraction data disclose that the phase transition is from the room-temperature phase with the space group C2/c to the low-temperature phase with the space group P1 with the Aizu notation of [a]