Synthesis and crystal structures of novel LaOAgS-type alkaline earth – Zinc, manganese, and cadmium fluoride pnictides

• Sight new alkaline earth – Mn, Zn, Cd fluoride pnictides were prepared.
• All new compounds adopt the LaOAgS structure type.
• Bond distances in their structures are transferable within 2–3%.
• Very close similarities are observed in structural chemistry of LaOAgS- and HfCuSi2-type compounds of Mn, Cu, Zn, Ag, and Cd.

Systematic studies of the LaOAgS-type compounds among alkaline earth – Zn/Cd/Mn fluoride pnictides revealed the existence of new representatives SrFMnP, SrFMnAs, SrFMnSb, SrFZnAs, SrFZnSb, BaFZnAs, BaFCdP, and BaFCdAs. Similar to rare-earth oxide compounds and contrary to isolobal chalcogenides of Cu/Ag, not all possible compositions could be realized. No compound of the structure type is formed for calcium; strontium forms fluoride pnictides only with zinc and manganese, while for barium, new representatives are also formed with cadmium. This trend, which possibly has a geometrical origin, is corroborated by quantum chemical calculations. Formation of NdOZnP-type compounds also was not observed suggesting the structure to be characteristic only for rare earth – zinc oxide phosphides.