Novel anionic water-containing inorganic fragment in [4-NH2PyH]8[Bi2Cl11] [Bi2Cl9(H2O)2]: Structural characterization, thermal, dielectric and vibrational properties

A novel compound, [4-NH2PyH]8[Bi2Cl11][Bi2Cl9(H2O)2] (abbreviated as 4APCB), was synthesized and structurally characterized at 100, 150 and 301 K. 4APCB crystallizes in a triclinic centrosymmetric space group, P1¯. The anionic framework is built up of two types of inorganic fragments, namely [Bi2Cl11]5-[Bi2Cl11]5- and [Bi2Cl9(H2O)2]3-[Bi2Cl9(H2O)2]3-, and 4-aminopyridinium- cations stacked between inorganic chains via π–π interactions. The latter type of anionic fragment was found for the first time in halobismuthate(III) solid complexes. Based on the results of differential scanning calorimetry (DSC), dilatometric and dielectric studies, 4APCB was found to undergo irreversible phase transition at ca. 342 K, accompanied by a partial decomposition of the compound (loss of water molecules). This chemical transformation is well reflected in the infrared spectrum of 4APCB.

Graphical abstractThe view of the independent part of the title compound crystal structure at 100 K. The probability of thermal ellipsoids is 50%. The numbering is shown for the independent part of the structure.Figure optionsDownload full-size imageDownload as PowerPoint slide