ИСТИНА

In this work, we report the synthesis and crystal structure of some new compounds featuring the Ag-Te or Ag-S framework with embedded oxoanions. Compounds were investigated with differently charged anions such as NO3-, SO42-, PO43-. General features of compounds frameworks are relarively high coordination numbers of chalcoges atoms and numerous silver-silver distances about 3 Å. We revealed that the frameworks structures are independent from the synthesis methods. Framework [Ag4Te]2+, contaning Ag44+ units, has identical structure in two compounds [Ag4Te]SO4 and [Ag4Te](NO3)2, the former being obtained at high temperature, whereas the latter was crystallized from the solution. Moreover the structure of [Ag3S]+ framework in [Ag3S]NO3 , which was precipitated from silver nitrate water solution , is different from [Ag4Te]2+ framework only by additional silver atoms, which is connected to Ag3+ forming Ag44+ tetrahedron. In all described compounds guest anions are located in the cage of 12 or 14 silver atoms , and the anions is distorted in accordance with the cage geometry. The influence of anion on the host framework dimention appears in two isostructural compouns [Ag5Te]PO4 and [Ag5Se]PO4. These compounds have a peculiar crystal structure featuring a two-dimensional framework [Ag5E]3+ and separate tetrahedral PO43- ions.