Ba₂[Ni₃N₂]: A Low‐Valent Nitridonickelate—Synthesis, Crystal Structure, and Physical Properties

Abstract

The ternary alkaline-earth nitridonickelate Ba2[Ni3N2] (Ba2[NiI2Ni0N2]) was prepared by the reaction of mixtures of Ba2N and Ni in nitrogen gas of ambient back-pressure at 1173 K. The crystal structure determined by X-ray single-crystal and powder diffraction methods as well as from neutron diffraction data at various temperatures between 2 and 298 K is orthorhombic (Cmca (no. 64), 298 K: a=715.27(18) pm, b=1032.99(21) pm, c=740.12(20) pm) and provides the first example of a nitridonickelate with a two-dimensional complex anion. The Ni2 atom is described with a split position and the corresponding superstructure variants are investigated by theoretical full-potential nonorthogonal local-orbital calculations (FPLO). The average oxidation state of Ni in Ba2[Ni3N2] is +0.67, the lowest average value observed in nitridonickelates so far. Investigations of the physical properties demonstrate that Ba2[Ni3N2] acts as a "poor" metal with a large resistivity of approximately 2.7 mOmega cm at 300 K and exhibits low-dimensional magnetism with antiferromagnetic ordering at T approximately 90 K. XAS spectra correspond with low-valent Ni states.

Ba2Ni3- a new phase in the binary system Ba-Ni

“…The chains in this compound are isolated from each other by organic groups which are connected to the chains by H-bonds only. The same type of structures has been recently described in the literature [1].…”

“…Therefore, the synthesis of these compounds with the high-melting RE metals is rather a difficult task. However, two new isomorphic compounds, Lu6B3.33S14 (yellow) and Ho6B3.33S14 (red), were obtained by a hightemperature high-pressure route from the elements [1] at 3 GPa (5 h, 1400 o C). The crystal structures were solved and refined using the Rietveld method.…”

“…Cd .. and organic groups. In the case of ethylenediamine inorganic chains were joined by diamine molecules forming two-dimensional layers (1,2), whereas in the case of triethyleneamine (a bigger molecule, one nitrogen atom) double inorganic chains with the formula Cd 2 Cl 5 (H 2 O) were formed (3). The chains in this compound are isolated from each other by organic groups which are connected to the chains by H-bonds only.…”

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

“…New compounds with extended nitridometalate structures can be of great interest in respect to magnetic and electronic properties. Up to now the most transition‐metal‐rich nitridometalates are Ba 2 [Ni 3 N 2 ] and La 3 [Cr 9.236 N 11 ] in alkaline‐earth and rare‐earth metal systems, respectively.…”

Low-dimensional magnetism in calcium nitridonickelate(ii) Ca2NiN2

“…Multinary 3d transition metal nitrides have been extensively investigated with ambient and medium pressure (< 1 GPa) synthesis methods for their diverse physical and electronic properties, their structural chemistry, and their close relation to the well-studied oxometallates. [1][2][3][4][5][6][7] However, access to nitrogenrich transition metal nitrides is limited by the low energy of nitride formation [8][9][10] and especially for later transition metals such as Co, Ni and Cu, the obtainable nitrides are usually nitrogen-poor and metallic: While in molecular chemistry lowcoordinate Ni II imido complexes and a transient Ni IV nitrido complex have been investigated, 11,12 currently reported solidstate nitridonickelates such as MNiN (M = Ca, Sr, Ba), Ba 2 Ni 3 2/3 N 2 , and Li 3 Sr 3 Ni 4 3/4 N 4, [13][14][15][16][17] feature low nitrogen to metal ratios and mean Ni oxidation states of +1 or lower. LiNiN is the only well-characterized compound with Ni(II) 18 as a proposed Na 2 HgO 2 -type Sr 2 Ni II N 2 was later shown to be a cyanonitridonickelate(0) i.e.…”