ChemInform Abstract: Dimers [Al₂N₆]^12‐ and Chains ¹_∞[AlN^3‐_4/2] in the Crystal Structures of Ca₆[Al₂N₆] and Ba₃[Al₂N₄].

Abstract

structure structure (solids and liquids) D 2000 27 -014 Dimers [Al 2 N 6 ] 12− and Chains 1 ∞[AlN 3− 4/2 ] in the Crystal Structures of Ca 6 [Al 2 N 6 ] and Ba 3 [Al 2 N 4 ].-Single crystals of the title compound are prepared by reaction of the corresponding metals in N 2 at 1000 • C (ambient pressure, 10 h). The structure of Ca[Al 2 N 6 ] is monoclinic and contains isolated dimeric [Al 2 N 6 ] 12− units formed by two edge-sharing AlN 4 tetrahedra. Ba 3 [Al 2 N 4 ] is isotypic with Sr 3 [Al 2 N 4 ] (orthorhombic, Pnna, Z = 4). In this structure, the AlN 4 tetrahedra form infinite chains by sharing trans-edges. -(LUDWIG, M.; NIEWA, R.; KNIEP, R.; Z. Naturforsch., B: Chem. Sci. 54 (1999) 4, 461-465; Eduard-Zintl-Inst., TH Darmstadt, D-64289 Darmstadt, Germany; EN)

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

“…Ba2 is coordinated by seven N atoms at distances of 2.82-3.07 Å and a further one at 4.06 Å. These distances are in good agreement with the typical values found in other nitridometalates containing Barium [24,27,29,32]. All nitrogen atoms in the structure have four Ba and two Mn atoms in the closest proximity ( Figure 3b).…”

“…An additional Ba1 atom at 3.44 Å and the Ba2 atom at the farthest corner residing at a distance of 4.06 Å complete the (6 + 2)-fold coordination of N2. A similar coordination of nitrogen is observed in the above-mentioned AE3[Al2N4] (AE = Sr, Ba) compounds [24,25] and can be regarded as a strongly distorted square anti-prism. The corresponding longest distance in Ba3[Al2N4] is 4.04 Å [24].…”

Ba4Al7Li28.08O26.92N1.08, the Barium Oxonitridolithoaluminate with a Highly Condensed LiO4 Tetrahedra Framework

“…Considering the Ba3 and Ba4 site, the Ba3–O distances are between 279.1(2) and 322.4(2) pm, while the Ba4–O distances range from 275.1(2) to 324.5(2) pm. The Ba–O/N distances of the Ba1 and Ba2 site, including the split position Ba3 and Ba4 site, correspond well with the sum of the ionic radii and are in good accordance with Ba–O/N distances known from literature. − The described split positions above are then referred to as the Ba2 site in the following. The polyhedra of the Ba1 and Ba2 sites could be described as distorted single-capped triangular cupola, which polyhedron shape could also be observed in compounds such as Eu 3 Be 22 N 16 O .…”

Structural Classification of Quasi-One-Dimensional Ternary Nitrides

“…A 3 M 2 N 4 (A = Sr, Ba; M = Al, Ga), space group Pnna, also show SiS 2 -like chains of tetrahedra [48][49][50][51]. In A 3 M 2 N 4 , the nitrogen atoms are in a distorted-cubic close-packed arrangement, with a quarter of the tetrahedral holes occupied by Ga 3+ /Al 3+ , generating the 1 In this case, the nitrogen atoms are eight coordinate, surrounded by six lithium atoms and two iron atoms to give a distorted cube.…”