ИСТИНА

Complex bismuth (III) halides have a wide variety of anionic substructures and in combination with organic or inorganic cations form an ever-expanding family of compounds. In these compounds, the anionic substructures’ assembling occurs as a result of {BiX6} octahedral sharing by vertex, edges or faces, resulting in polynuclear anions involving from 2 to 10 octahedra or one-dimensional infinite anionic chains. It is assumed that the nature of the cation is one of the fundamental factors affecting the process of the octahedral condensation and the final iodobismuthate anions nuclearity. However, among many other factors influencing the iodobismuthates anionic substructure organization is the interstitial Br2 or I2 molecules acting as bridges. In this case, Br2/I2 moieties combine Bi/X anions into extended architectures by alternating shorter covalent and longer secondary bonds [1]. Herein we report on the synthesis, crystal and electronic structure, and properties of several new bismuth polyiodides: (NH4)7Bi3I16(I2)0.5∙4.5H2O, K18Bi8I42(I2)0.5∙14H2O, [PDA(BiI4)2∙I2] (PDA = phenylenediammonium, [NH3C6H4NH3]2+) and [(C5NH10OH)3Bi2I9∙I2] (C5NH10OH = 3-hydroxypiperidinium) in which I2 molecules serve as additional linkers for increasing the anionic substructure dimensionality. It is shown that in the presence of interstitial I2 linkers the number of octahedra condensed in anionic substructures changes, and the possibility of combining several polynuclear fragments in the same crystal structure appears. The bonding within iodobismuthate clusters and interstitial I2 moiety was analysed using electronic structure calculations.