(Ca₇N₄)[M_x] (M=Ag, Ga, In, Tl): Linear Metal Chains as Guests in a Subnitride Host

Li16Sr6Ge6N, Li16Sr6Ge6.5 and related lithium alkaline‐earth metal tetrelides: Alternative filling of voids by nitride or tetrelide ions

“…[12] However, the presumed electron transfer from cations to anions in these phases may be sometimes overstated and both interactions between the cationic and anionic parts of these structures and mixing of states may play an important role in stabilizing these phases, [13] resulting in rather unexpected properties like metallic behavior in Ca 7 N 4 [Ga 1 .33 ]. [14] In this contribution, we demonstrate that depending on whether nitrogen is offered within the starting mixture, either metalide nitrides or intermetallic compounds can be obtained in the systems LiÀ AeÀ Tt(À N) (Ae = Ca, Sr; Tt = Si, Ge, Sn, Pb). The obtained phases have a very similar composition and only quite subtle differences in the crystal structures with germanide or nitride ions providing a part of the anionic substructure, but occupying different crystallographic sites.…”

“…In most of the phases discussed above, both complex anions and metalide ions can be described on the basis of the extended Zintl‐Klemm‐concept [12] . However, the presumed electron transfer from cations to anions in these phases may be sometimes overstated and both interactions between the cationic and anionic parts of these structures and mixing of states may play an important role in stabilizing these phases, [13] resulting in rather unexpected properties like metallic behavior in Ca 7 N 4 [Ga 1.33 ] [14] …”

Alkaline‐earth Metal Nitrides of the Main‐Group Elements: Crystal Structures and Properties of Inverse Perovskites

“…On increasing the In or Tl content in the composition related phases with E-E covalent bonding, nitrogen exclusively sur- 8 ] ions of more complicated shape (2-fold edge-capped octahedron), [62] to infinite chains contained in, e.g., (Ca 7 N 4 )E x (E = In, Tl, x close to 1), [63] (Ca 2 N)In, [64] and [66] A close similarity in structural chemistry and chemical bonding properties of these compounds to isostructural compounds containing anionic silver or gold next to nitride ions is indicated with the existence of (Ca 19 N 7 )[Ag 4 ], [67] (Ca 7 N 4 )Ag x (x = 2.72), [68] and (A 2 N)Au. [68,69] Originally the cubic calcium Perovskites with E = Ge, Sn, Pb were reported with the composition (Ca 3 N)E, [18] later the systems Sr,Ba-Sn,Pb-N were exemplarily studied in deeper detail indicating the formation of further cubic Perovskites but with a nitrogen deficiency according to (A 3 N x )E. [20,70] DTA/ TG measurements on melt beads with the general composition "A 3 E" in nitrogen atmosphere already indicated the uptake of less than one equivalent nitrogen per "A 3 Sn,Pb" composition.…”

One-dimensional composite host–guest structure in BaVS3

“…This controversy could be resolved by applying an approach called the host-guest commensurate composite structure (Arakcheeva et al, 2002;Hö hn et al, 2006;McMahon & Nelmes, 2006). This type of crystal structure assumes different symmetries for the host (usually a 3D matrix) and the guest The group-subgroup relationships for BaVS 3 between 10 and 295 K. The bold black arrows indicate the relationships within the host (H) and the guest (G) components of the structure.…”