Synthesis, Crystal Structure, and Dielectric Properties of (3-Aminopropyl-imidazolium) Pentachlorobismuthate (III) [C6H13N3]BiCl5

A new organic–inorganic hybrid material of formula [C6H13N3]BiCl5 was synthesized and characterized by X-ray diffraction. This compound crystallizes in the monoclinic system with space group P21/n. The unit cell dimensions are a = 10.287(5) A, b = 13.845(7) A, c = 10.605(6) A and β = 108.46(3)° with Z = 2. The atomic arrangement can be described as an alternation of organic and inorganic layers. The anionic layer is built up of bioctahedral [Bi2Cl10]4− arranged in sandwich between the organic ones. The crystal packing is governed by means of the N–H···Cl hydrogen bonds, forming a three dimensional network. Differential scanning calorimetry and thermogravimetric analysis disclose structural phase transition of order–disorder type at 465 K. Dielectric investigations revealed a step-wise change of the electric permittivity at Ttr1 characteristic of the crystal in the high-temperature phase. The evolution of dielectric constant as a function of temperature of the sample has been investigated in order to determine some related parameters. Solid-state 13C MAS NMR spectroscopy results are in agreement with the X-ray structure.