Preparation and Single-Crystal Structure Analysis of Ca2NF

Abstract

Single-crystalline samples of Ca 2 NF were prepared by heating a stoichiometric mixture of Ca metal and CaF 2 under N 2 to 10003 3C, followed by slow cooling from the melt. The resulting Ca 2 NF crystals were yellow in color, and highly air-sensitive. A single-crystal X-ray di4raction analysis indicated that the compound is isostructural with L-Mg 2 NF, with tetragonal cell parameters a ‫؍‬ 4.9018(9) A s and c ‫؍‬ 10.516(3) A s , Z ‫؍‬ 4, and space group I4 1 /amd (No. 141). X-ray re5nement was carried out by full-matrix least-squares on F 2 on all data, to give R 1 ‫؍‬ 0.0426 (all data) and wR 2 ‫؍‬ 0.0630 for 12 parameters and 101 independent re6ections. The 5nal position assignments were analyzed via bond valence sum calculations. Academic Press

Layered electrides as fluoride intercalation anodes

“…We note that while Ca2NCl and Ca2NBr are experimentally reported to exist in the 3 ̅ phase, 34,35 Ca2NF has only been made in the I41/amd phase, 36 which we find is 5 meV/atom higher in energy than the 3 ̅ phase. Therefore, we expect that low-temperature fluorination, which has emerged as a successful strategy to produce fluoride structures topochemically, 37,38 should yield 3 ̅ Ca2NF from 3 ̅ Ca2N.…”

Layered Electrides as Fluoride Intercalation Anodes

“…We note that while Ca2NCl and Ca2NBr are experimentally reported to exist in the 𝑅3 ̅ 𝑚 phase, 34,35 Ca2NF has only been made in the I41/amd phase, 36 which we find is 5 meV/atom higher in energy than the 𝑅3 ̅ 𝑚 phase. Therefore, we expect that low-temperature fluorination, which has emerged as a successful strategy to produce fluoride structures topochemically, 37,38 should yield 𝑅3 ̅ 𝑚 Ca2NF from 𝑅3 ̅ 𝑚 Ca2N.…”

Crystal growth and redetermination of strontium nitride iodide, Sr2NI

“…Sr 2 NI belongs to the A 2 NX (A = Ca-Ba, X = F-I) family of compounds which were originally synthesized several decades ago (Ehrlich & Deissmann, 1958;Ehrlich et al, 1964;Emons et al, 1964;Emons et al, 1968;Andersson, 1970;Ehrlich et al, 1971). It has only been recently that the structures and properties of these compounds have been revealed (Hadenfeldt & Herdejürgen, 1987;Hadenfeldt & Herdejürgen, 1988;Bowman et al, 2001;Nicklow et al, 2001;Reckeweg & DiSalvo, 2002;Wagner, 2002;Sebel & Wagner, 2004;Bowman et al, 2005;Jack et al, 2005;Bowman et al, 2006). With the exception of Ca 2 NX (X = Cl, Br, I) (Hadenfeldt & Herdejürgen, 1987;Hadenfeldt & Herdejürgen, 1988), single-crystal determinations have been restricted to the lighter halide (X = F) members.…”