Expanding the structural versatility of thiostannate(iv) complexes

Abstract

The synthesis of new thiostannate(IV) complexes is of key importance for further progress in the formation of both extended thiostannate compounds and multinary tin sulphide containing functional materials. Here we report on the crystal structures of three new thiostannate(IV) compounds with complex structures: ((CH₃C(NH₂)₂)₈Sn₂S₆SnS₄1, ((CH₃)₂NH₂)(NH₄)SnS₃2 and (NH₄)₆Sn₃S₉·1.3H₂O 3). They have been synthesised by utilising different crystallisation solvents (DMF and acetonitrile) starting from the same ammonium thiostannate(IV) containing solution. The size and shape of the thiostannate(IV) complexes take the form of discrete monomeric [SnS₄]⁴⁻ and dimeric [Sn₂S₆]⁴⁻ complexes in 1, infinite linear [SnS₃]²⁻ chains in 2 and as a trimeric six-membered [Sn₃S₉]⁶⁻ complex in 3. Hirshfeld surface analysis shows that the number of interacting hydrogen atoms with the thiostannate(IV) complex in 3 is responsible for elongation of the Sn–S bonds, regardless of the origin of the hydrogen atom (neutral water molecules or charged ammonium cations). Furthermore, statistics on the bond distances and angles for the most common dimeric thiostannate(IV) complex [Sn₂S₆]⁴⁻ is collected and compared with the three thiostannate(IV) structures obtained here.