The layered polyphosphide Ag3.73(4)Zn2.27(4)P16

The silver zinc hexa-deca-phosphide Ag3.73(4)Zn2.27(4)P16 is the first polyphosphide in the ternary system Ag/Zn/P. It was synthesized from stoichiometric mixtures of Ag, Zn and P in the molar ratio 4:2:16, using AgI as a mineralizing agent in a gas-phase-assisted reaction. Ag3.73(4)Zn2.27(4)P16 crystallizes in the Cu5InP16 structure type. The asymmetric unit contains two Ag/Zn sites with mixed occupancies and four P sites. One of the Ag/Zn sites is located on a twofold rotation axis. The polyanionic [P16]-substructure consists of corrugated six-membered rings that are connected into a layer via the 1-, 2-, 4- and 5-positions of the rings by a bridging P atom in each case. The layers extend parallel to the bc plane and are stacked along the a axis. Both Ag/Zn sites are tetra-hedrally coordinated by P atoms.