Lanthanido ammonium cations [NM4]9+ as main structural features in lanthanide(III) nitride chalcogenides and their derivatives

All lanthanide(III) nitride chalcogenides contain lanthanido ammonium cations [NM4](9+) (M=La-Lu) as main structural features. They can occur isolated ((0)(infinity) ([NM4](9+)}, N:M= 1:4) as in compounds of the compositions M(4)NCh(3)X(3) (Ch=S, Se; X=Cl, Br) and NaM10NS14 Or form discrete [N2M6](12+) units (N:M = 1:3) as a pair of tetrahedra with a common edge in the M5NSe6-type representatives. With the same stoichiometry (N:M = 1:3), but a one-dimensional infinite solution (1)(infinity){[NM3](6+)}, they share two vertices to build up chains in the formula types M(3)NCh(3) (Ch = S, Se) and CsM6N2,Te-7. By sharing two edges (cis-oriented in M(4)N(2)Ch(3) (Ch = S, Se), trans-oriented in M4N2Te3 and M5N2Se4Br), chains of the composition (1)(infinity)[NM2,](3+)} (N:M = 1:2) are generated, but also the condensation via one fused edge and two common comers can lead to chains of the same stoichiometry ((1)(infinity)[NM2] (3+)}) in M4N2S3, when pairs of edge-shared bitetrahedra ([N2M6](12+)) join with their four free vertices. The latter way of interconnection is used to construct even porous layers infinity 2[NM2](3+)} in the nitride chalcogenides M(4)N(2)Ch(3) with four-and-eight(Ch = S) or double-six-ring pores (Ch = Se). Two different types of chains (a cis-edge shared one and a one edge plus two comers shared one, both commensurate by translation) characterize the structure of the nitride chalcogenide halogenides with the formula M6N3S4X (X=Cl, Br), without changing the overall composition (N:M = 1:2). When two chains of cis-edge shared [NM4](9+) tetrahedra are connected by an extra edge per unit, a complex strand with the composition (1)(infinity) ([N2M3](3+)) (N:M = 1:1.5) emerges as in the mixed anion compounds M3N2SeBr. Almost the same (1)(infinity){[N2M3](3+))-chain feature is exhibited by one of the two different chains in compounds such as M5N3S2Cl2, where the other one displays the motif of the pairs of edge-shared bitetrahedra ([N2M6](12+)) interconnected via their four free vertices ((1)(infinity) {[NM2 ](3+)}). (c) 2007 Elsevier B.V. All rights reserved.