Tuneable tetrel bonds between tin and heavy pnictogens.

The first example of a binary cocrystal, comprised of SnPh3Cl and PPh3, whose components are organized via short and directional tetrel bonds (TtB) between tin and phosphorus, is described. DFT elucidates, for the first time, the factors influencing the strength of TtBs involving heavy pnictogens. A CSD survey reveals that such TtBs are also present and determinative in single component molecular systems, highlighting their significant potential as tuneable structure-directing elements.