Ca₁₂[Mn₁₉N₂₃] and Ca₁₃₃[Mn₂₁₆N₂₆₀]: Structural Complexity by 2D Intergrowth

Abstract

Two new calcium nitridomanganates, Ca12[Mn19N23] (P3, a=11.81341(3) Å, c=5.58975(2) Å, Z=1) and Ca133[Mn216N260] ( , a=39.477(1) Å, c=5.5974(2) Å, Z=1), were obtained by a gas–solid reaction of Ca3N2 and Mn with N2 at 1273 K and 1223 K, respectively. The crystal structure of Ca12[Mn19N23] 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 Ca133[Mn216N260] 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.

Ba4[Mn3N6], a Quasi-One-Dimensional Mixed-Valent Nitridomanganate (II, IV)

“…Such a description provides a link between salt-like alkaline-earthmetal-rich nitridometalates [50], like Li7[MnN4] [40] and Ba3[MnN3] [32], and transition-metal-rich nitrides with pronounced metal-metal interactions, like Ca12[Mn19N23] [47] and Mn4N [36] (Figure 9). …”