Ca 12 [Mn 19 N 23 ] and Ca 133 [Mn 216 N 260 ]: Structural Complexity by 2D Intergrowth

Two new calcium nitridomanganates, Ca 12 [Mn 19 N 23 ] ( P 3, a =11.81341(3) Å, c =5.58975(2) Å, Z =1) and Ca 133 [Mn 216 N 260 ] ( P 3 ‾ , a =39.477(1) Å, c =5.5974(2) Å, Z =1), were obtained by a gas–solid reaction of Ca 3 N 2 and Mn with N 2 at 1273 K and 1223 K, respectively. The crystal structure of Ca 12 [Mn 19 N 23 ] was determined from high‐resolution X‐ray synchrotron powder diffraction data, whereas single‐crystal X‐ray diffraction was employed to establish the crystal structure of the Ca 133 [Mn 216 N 260 ] phase, which classifies as a complex metallic alloy (CMA). Both crystal structures have 2D nitridomanganate layers containing similar building blocks but of different levels of structural complexity. Bonding analysis as well as magnetic susceptibility and electron spin resonance measurements revealed that only a fraction of the Mn atoms in both structures carries a localized magnetic moment, while for most Mn species the magnetism is quenched as a result of metal–metal bond formation.